The Singapore Engineer December 2016 by The Singapore Engineer

The Magazine Of The Institution Of Engineers, Singapore December 2016 MCI (P) 002/03/2016

Celebrating 50 Years of Engineering Excellence

www.ies.org.sg

THE

SINGAPORE ENGINEER COVER STORY: CIVIL & STRUCTURAL ENGINEERING

HDB project demonstrates safety in design and construction

FEATURES: • Health & Safety Engineering • Concrete Technology • Precision Engineering

CONTENTS Celebrating 50 Years of Engineering Excellence

Founded in 1966

FEATURES 22 CIVIL & STRUCTURAL ENGINEERING: COVER STORY: HDB project demonstrates safety in design and construction The creation of sky bridges and non-uniform floor layouts were among the major challenges in the project.

28 HEALTH & SAFETY ENGINEERING: The collapse of table formworks at a construction site - a case study

30 HEALTH & SAFETY ENGINEERING: Design and testing of a crash bollard system Software-based simulation of its performance matched crash test results.

34 CONCRETE TECHNOLOGY: Advances in the use of concrete for supertall buildings Technological developments have contributed to improved properties of the material while minimising possible problems.

40 PROJECT APPLICATION: Repair work on the Parks Viaduct in Milan Several construction chemical products were used in the multi-step process.

44 PRECISION ENGINEERING: Map for transforming Precision Engineering industry released The new growth areas in manufacturing are identified and the strategies for exploiting their potential are outlined.

02 MESSAGE 04 INDUSTRY NEWS 14 EVENTS 45 IES UPDATE

CEO Angie Ng angie@iesnet.org.sg Publications Manager Desmond Teo desmond@iesnet.org.sg

The incident is analysed and valuable lessons shared.

REGULAR SECTIONS

Chief Editor T Bhaskaran t_b_n8@yahoo.com

Publications Executive Queek Jiayu jiayu@iesnet.org.sg Media Consultant Roland Ang roland@iesnet.org.sg Published by The Institution of Engineers, Singapore 70 Bukit Tinggi Road Singapore 289758 Tel: 6469 5000 Fax: 6467 1108 Cover designed by Irin Kuah Cover image by Housing & Development Board

The Singapore Engineer is published monthly by The Institution of Engineers, Singapore (IES). The publication is distributed free-of-charge to IES members and affiliates. Views expressed in this publication do not necessarily reflect those of the Editor or IES. All rights reserved. No part of this magazine shall be reproduced, mechanically or electronically, without the prior consent of IES. Whilst every care is taken to ensure accuracy of the content at press time, IES will not be liable for any discrepancies. Unsolicited contributions are welcome but their inclusion in the magazine is at the discretion of the Editor.

Design & layout by 2EZ Asia Pte Ltd Printed in Singapore

December 2016 THE SINGAPORE ENGINEER

MESSAGE

Digitalisation and Sustainability among key issues for engineers Globally, Year 2016 has been a tumultuous period, with political and economic uncertainties that continue to cloud our vision, as we prepare to usher in the New Year. For the engineering sector in Singapore, these developments have created challenges for companies as they have had to work very hard to remain profitable and ensure sufficient demand for their products. Many specific industries have suffered, however, resulting in retrenchment of staff, including engineers. There is therefore a need for engineers to upgrade their skills (upskill) and to acquire new qualifications (reskill). In this context, the IES Chartered Engineers Programme could be an attractive option. Being registered as a Chartered Engineer (Singapore) will be an external validation of one’s experience, expertise and competence, and could open new avenues of employment for engineers. At the same time, the ‘disruptive’ impact of digitalisation has already begun to be felt by the engineering industries. Experts have stated that whilst this process is going to intensify further, with its weakening effect on the security of employment, it will also create tremendous opportunities for those who are able to exploit the full potential of these phenomenal changes.

IES Council Members 2016 / 2017 President Er. Edwin Khew Vice Presidents Er. Chan Ewe Jin Mr Mervyn Sirisena Er. Ng Say Cheong Er. Ong See Ho Er. Seow Kang Seng Dr Yeoh Lean Weng Honorary Secretary Dr Boh Jaw Woei Honorary Treasurer Er. Joseph Goh Immediate Past President Er. Chong Kee Sen

“… more needs to be done as the demand for engineers is expected to increase in the years ahead – not just in the application of existing and new technologies but also in research and development ...” It is too soon to make a judgement on how fast and how much this development will affect all engineering activity, but there will certainly be great demand for those with qualifications in Information and Communications Technology (ICT) and Electronics Engineering, in the years ahead. Regional co-operation will also create opportunities. A good example is the bilateral agreement recently signed by Singapore and Malaysia for the High-Speed Rail project. Railway Engineering, as a subject will acquire added importance, with areas of highlighted interest such as infrastructural development, operations, maintenance and asset management. And a continuing objective for engineers and scientists is the development of products and technologies that help to minimise the use of resources as well as the generation of waste, in order to ensure a sustainable future. This brings into focus the need to motivate students to take up engineering as a career of choice. Efforts are ongoing, but more needs to be done as the demand for engineers is expected to increase in the years ahead - not just in the application of existing and new technologies but also in the field or research and development which will extend the boundaries of what is possible, even further. These priorities will continue to engage the attention of thinkers and decisionmakers from the engineering sector, in 2017.

Editor The Singapore Engineer

THE SINGAPORE ENGINEER December 2016

Past Presidents Prof Chou Siaw Kiang Er. Ho Siong Hin Assistant Honorary Secretary Mr Joseph William Eades Er. Joseph Toh Dr Lim Kok Hwa Assistant Honorary Treasurer Mr Tan Sim Chuan Council Members Prof Chan Eng Soon Dr Chew Soon Hoe Mr Dalson Chung Mr David So Prof Er Meng Joo Mr Goh Yang Miang Ms Jasmine Foo Mr Lee Kwok Weng A/Prof Lee Poh Seng Mr Norman Lee Prof Ramakrishna Seeram Er. Teo Chor Kok Dr Zhou Yi Honorary Council Members Er. Dr Lee Bee Wah Er. Ong Ser Huan Er. Tan Seng Chuan

December 2016 THE SINGAPORE ENGINEER

INDUSTRY NEWS

Bentley Systems announces collaboration arrangements Bentley Systems, a leading global provider of comprehensive software solutions for advancing infrastructure, and Topcon Positioning Group, a world leader in positioning instruments for survey and construction, have announced their joint intentions to connect cloud services for ‘constructioneering’. During keynote presentations at Bentley’s Year in Infrastructure 2016 Conference, the CEOs of the two companies presented new construction workflows designed to increase efficiency and productivity with enhanced integration between their respective cloud services. Each company will bring to market cloud-based solution offerings, which include services of both, and provide construction workflows not previously possible. Initially, Bentley will offer its ProjectWise CONNECT Edition users seamless connectivity with Topcon’s MAGNET Enterprise, and Topcon will incorporate Bentley Systems’ ContextCapture image processing for its mass data collection via unmanned aerial systems (UAS). Compared to traditional workflows between design and construction, in which data from survey and digital engineering models can be lost and inefficiently recreated, constructioneering empowers engineers to extend their role within both surveying and construction. Cloud services first bring the construction site conditions to the engineers so that their work starts with an accurate model of the current 3D context - as captured by Topcon UAS photogrammetry and laser scanners and then processed into engineeringready 3D reality meshes, by Bentley’s ContextCapture software. Cloud services subsequently convey the engineers’ work directly to construction processes in the field.This automation process, achieved through the connection between Topcon MAGNET cloud service and Bentley’s ProjectWise CONNECT Edition cloud services, improves project delivery, with 04

design performed in context, and the resulting digital engineering models feed the 3D machine control that guides the construction machinery. Topcon and Bentley expect to expand the constructioneering workflow to further applications for infrastructure services. At the Year in Infrastructure 2016 Conference, Bentley Systems also announced that its new AssetWise CONNECT Edition (introduced at the conference) and ProjectWise CONNECT Edition (introduced at Year in Infrastructure 2015) support hybrid computing environments across desktops, mobile devices, and in-house servers. And together, ProjectWise CONNECT Edition and AssetWise CONNECT Edition leverage Microsoft’s Azure cloud services to advance beyond common data environments to connected data environments. During conference keynotes, Bentley and Microsoft discussed the advancements made possible through their partnership and some of their future priorities working together. Bentley Systems’ CEO, Greg Bentley, offered user organisations the company’s plans for ‘going digital’ through Azure, to ensure that the ‘BIM potential’, created through digital engineering models, can be fully realised in infrastructure project delivery and asset performance. The Azure-provisioned connected data environment

experiences and benefits realised by Crossrail, Shell, Maryland State Highway Administration, and Mott MacDonald, were cited. According to Bentley, the next step for connected data environments is to enable business- and operationalintelligence analytics to have open and live access to information within digital engineering models, in order that ‘ET’ (engineering technologies) can support ‘IT’ and ‘OT’ (operational technologies) to improve the throughput, safety, and reliability of infrastructure asset performance. Year in Infrastructure 2016 Conference Bentley’s Year in Infrastructure Conference is a global gathering of leading executives in the world of infrastructure design, construction, and operations. The conference features a series of presentations and interactive workshops exploring the intersection of technology and business drivers, and how they are shaping the future of infrastructure project delivery and asset performance. The Year in Infrastructure 2016 Conference was held from 1 to 3 November 2016, in London, UK. A highlight of the conference was the presentation of the 2016 Be Inspired Awards. The awards recognise excellence and innovation in the design, construction and operation of infrastructure projects around the world.

At Bentley’s Year in Infrastructure 2016 Conference, the City of Helsinki, in Finland, won the 2016 Be Inspired Award, under the category ‘Innovation in Reality Modelling’, for ‘Helsinki 3D+’.

THE SINGAPORE ENGINEER December 2016

INDUSTRY NEWS

Government announces support measures for marine & offshore engineering companies The Ministry of Trade and Industry announced on 25 November 2016 enhancements to IE Singapore’s Internationalisation Finance Scheme (IFS) and the re-introduction of SPRING’s Bridging Loan (BL) for companies in the Marine and Offshore Engineering (M&OE) industry. These measures will help to address the intensifying financing challenges faced by the M&OE industry in recent months, as it experiences a unique and prolonged slowdown. The schemes aim to facilitate M&OE companies’ access to working capital and financing. For example, the

BL will help Singapore-based M&OE companies finance their operations and bridge short-term cash flow gaps. Eligible companies will be able to borrow up to SGD 5 million each, with a loan tenure of up to six years. The maximum loan quantum for each borrower group is SGD 15 million. For IE Singapore’s existing IFS, which provides project/asset financing support for companies, the maximum loan quantum will be raised to SGD 70 million per borrower group from the current SGD 30 million for M&OE companies. These one-off measures, developed

in consultation with industry players, are targeted at stabilising the M&OE sector, as it copes with the prolonged weakness in oil prices amidst the slowdown and uncertainty in the global economic environment. The Government will take on 70 per cent of the risk-share for both BL and IFS. The BL and IFS will be available from December 2016 and could catalyse about SGD 1.6 billion of loans over a period of one year. For more information, visit the IE Singapore and SPRING websites at http://www.iesingapore.gov.sg/ and http://www.spring.gov.sg/ respectively.

December 2016 THE SINGAPORE ENGINEER

INDUSTRY NEWS

Rockwell Automation names new president for Asia-Pacific region

Mr Joseph Sousa. Photo: Rockwell Automation

Rockwell Automation has named Mr Joseph Sousa president of its AsiaPacific region. Mr Sousa, who recently served as president for Latin America, will be responsible for executing the company’s growth and performance strategy, and leading the commercial and selling organisation in China, India, South Pacific, Southeast Asia, Korea and Japan. The Asia-Pacific region contributed nearly USD 850 million in sales for the 2015 fiscal year. “Joe builds high-performance teams and develops leaders. Both skills will be critical to achieving our

business objectives in Asia-Pacific,” said Mr John McDermott, senior vice president, global sales and marketing. “His long and successful career makes him ideal for this important leadership role.” Mr Sousa joined Rockwell Automation in 1988, serving as a district manager, sales vice president and regional president. He succeeds Mr Tom O’Reilly, who will be transferred to the United States to become Rockwell Automation’s vice president for global business development. Mr O’Reilly has over 25 years of service with the company as a global business leader.

LG Electronics promotes head of successful home appliance business to company CEO LG Electronics announced on 1 December 2016 that Mr Jo Seong-jin, the head of its Home Appliance & Air Solution (H&A) Company and one of the three Representative Directors responsible for key decisions of the entire organisation, has been promoted to the position of CEO with immediate effect. Mr Jo will oversee the entirety of LG Electronics’ business units including the H&A Company, Mobile Communications, Home Entertainment and Vehicle Components, as well as 120 operations around the world. The 60-year-old, who joined LG’s predecessor Goldstar in 1976, was part of the team which developed LG’s first automatic washing machine in 1980. Prior to becoming president of the H&A Company in 2015, he was the head of LG’s H&A washing machine division. In 2007, Mr Jo received the Bronze Tower Order of Industrial Service Merit from the Korean government in recognition of his valuable contributions to the development of new

Mr Jo Seong-jin.

Mr Song Dae-hyun.

technologies and the Korean industry. More recently, he was instrumental in LG’s move into premium appliances with the introduction of the LG SIGNATURE brand and built-in Signature Kitchen Suite as well as building the foundation for future businesses in the areas of IoT (Internet of Things) and smart homes. Mr Jo’s former position will be filled by Mr Song Dae-hyun, 58, currently the head of LG in the Commonwealth

of Independent States (CIS) as well as president of LG Russia. A 33-year veteran of LG Electronics, Mr Song has been involved on the business side of nearly every major product line of the H&A Company, including air conditioners, refrigerators and cooking appliances. As head of Russia and CIS since 2012, he was responsible for successfully growing LG’s business in the region during an economically challenging period.

THE SINGAPORE ENGINEER December 2016

INDUSTRY NEWS

*Reproduced with permission from the Workplace Safety and Health (WSH) Insitute Note: 2016 ďŹ gures are preliminary

December 2016 THE SINGAPORE ENGINEER

INDUSTRY NEWS

German MNC sets up high-tech logistics facility in Singapore

Dr Gunther Kegel, CEO of Pepperl+Fuchs Group (left) takes Minister of Trade and Industry (Industry) S. Iswaran (second from left) on a tour through the Global Distribution Centre. Photo: Pepperl+Fuchs Group

German controls and automation manufacturer Pepperl+Fuchs marks another milestone in Singapore with the opening of its newly established, five-storey Global Distribution Centre in Jurong. With an investment of over SGD 65 million and spanning an area of 17,700sqm, the state-of-the-art centre serves as the central warehouse from which Pepperl+Fuchs Group provides worldwide distribution of more than 15,000 products. Integrated with the Internet of Things (IoT)-enabled high bay automated storage and retrieval system (ASRS) and an Intelligent Warehouse Management Software system, the fully automated warehouse will increase productivity by more than 400 per cent. This will allow Pepperl+Fuchs to increase its efficiency and cost-effectiveness while providing customers with shorter delivery times. “Facilitating a worldwide control tower function out of Singapore will enable us to manage the entire logistics process, which includes tracking, distribution, and production planning more

efficiently,” said Dr Gunther Kegel, CEO of Pepperl+Fuchs Group. “Additionally, our decision to include some of the latest Industry 4.0 concepts within our Global Distribution Centre is also a demonstration of our commitment to take on the leadership role in this exciting new space.” The centre will also include one floor of manufacturing operations, in which the deployment of automated guided vehicles (AGV) will automate the moving of both raw materials and finished goods between ASRS and the production lines. “We warmly welcome Pepperl+Fuchs’ decision to set up its Global Distribution Centre in Singapore, which will further strengthen its existing manufacturing presence here. The success of this facility is underpinned by the holistic application of industrial Internet of Things technologies, which Singapore has identified as a key capability in our advanced manufacturing pillar,” said Mr. Yeoh Keat Chuan, managing director of the Economic Development Board.

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MHE-Demag opens South East Asia’s largest crane manufacturing plant in Malaysia MHE-Demag, a joint venture between Terex MHPS GmbH and Jebsen & Jessen (SEA) Pte Ltd, has officially opened its largest manufacturing and warehouse facility in Bukit Raja, Malaysia. Developed at a cost of MYR 45 million, the facility can operate at a capacity of 200,000 production hours a year, a 54% increase from the previous site. It is expected to support the fabricated metal products and machinery & equipment industries. With a built-up area of close to 15,000 square metres, the plant is also the largest and first-of-its kind crane manufacturing facility in Malaysia and the region. Capable of building cranes of up to 50-metre span, it will primarily serve customers from Malaysia, Australia, Cambodia, Myanmar and Singapore, who hail from various industrial sectors where lifting, moving and maintenance of materials or machinery are required.

INDUSTRY NEWS

A*STAR and NUS establish national centre of excellence to advance Singapore’s marine & offshore engineering industry A next-generation Deepwater Ocean Basin research facility at NUS will leverage petascale supercomputing capabilities for integrated physical modelling and numerical simulation. The Agency for Science, Technology and Research (A*STAR) and the National University of Singapore have established a joint venture to spur research excellence and advance Singapore’s marine & offshore engineering (M&OE) industry. Named the Technology Centre for Offshore and Marine, Singapore (TCOMS), it is also supported by the Economic Development Board (EDB) and the Maritime and Port Authority of Singapore (MPA). The launch of the centre on 31 October 2016 was officiated by Mr S. Iswaran, Minister for Trade and Industry (Industry). Through strategic global partnerships with industry, research institutions and academia, TCOMS aims to sustain Singapore’s leadership position in the sector by enabling the local M&OE industry to undertake highervalue activities. “TCOMS is an excellent national platform to facilitate partnerships under an open innovation framework to draw on the strengths of our public sector research performers to develop meaningful industry collaborations locally and beyond. This joint initiative by A*STAR and NUS will position Singapore as a key hub for M&OE research globally,” said Mr Lim Chuan Poh, Chairman of A*STAR. State-of-the-art research capabilities A key feature of TCOMS is a next-generation Deepwater Ocean Basin with forefront simulation capabilities, including smart sensing and integrated physical modelling and numerical simulation. Currently being constructed at NUS, it is scheduled for completion in 2019 and boasts state-of-the art wave and current generation systems that could

Artist’s impression of the TCOMS building at NUS. Image:Technology Centre for Offshore and Marine, Singapore

(Foreground, left to right) Prof Chan Eng Soon, CEO of TCOMS; Mr S Iswaran, Minister for Trade and Industry (Industry); and Prof Tan Chorh Chuan, President of NUS, at the launch of TCOMS. Photo: NUS

simulate harsh ocean environments, including those in ultra-deep waters. This would facilitate the development of innovative concepts including intelligent floating platforms and ships, autonomous systems, marine robotics and subsea systems. Professor Chan Eng Soon, CEO of TCOMS and Provost’s Chair Professor in the Faculty of Engineering, NUS, explained, "A key differentiator in TCOMS is the development of a simulation system featuring the integration of basin modelling, numeri-

cal modelling, smart-sensing, and real time data analytics. “This novel approach will not only enhance the value-added services for the clients, but also unleashes new opportunities to better understand non-linear fluid structure interactions in complex sea states. “It will also pave the way for the development of intelligent systems that would help transform the M&OE industry, especially in the enhancement of efficiency, safety and reliability in harsh environments.”

December 2016 THE SINGAPORE ENGINEER

INDUSTRY NEWS

More built-up areas considering solar power as cleaner alternative Homegrown solar power company Sunseap Group has clinched two deals with Singapore-based premise owners to install solar panels as an alternative to fossil-fuel energy. Under a 25-year Solar Power Purchase Agreement with Panasonic Factory Solutions Asia Pacific, more than 3,400 solar panels have been installed on the roof areas across three factory buildings located at Jalan Ahmad Ibrahim. This is the second solar project undertaken between Sunseap and Panasonic in Singapore, after a successful implementation at the latter’s Refrigeration Devices complex in Bedok last year. The 2016 roll-out was completed in September and enables the generation of some 1.2 million kilowatthours (kWh) of solar energy annually, enough to power 3,000 four-room HDB flats. It will also reduce the factory complexes’ yearly carbon dioxide emissions by about 500 tonnes. At its peak, the factory’s photo-

voltaic (PV) system is expected to power, on average, close to 20% of its entire energy consumption. The solar panels, which can maintain their performance at the high temperatures found in tropical climates, are manufactured in Malaysia. “This is definitely a value-creating initiative towards our environmental and energy sustainability contribution,” stated Mr Tatsuyoshi Ishii, Managing Director of Panasonic Factory Solutions Asia Pacific. “Together with Sunseap, we hope to reduce our operational carbon footprint and promote the significance of solar energy usage in executing business activities.” Solar education and an active, healthy lifestyle Seeking to use renewable energy in a different way is Tanglin Academy (TA), a tennis school located at Turf City in Bukit Timah. Sunseap will collaborate with the academy to install solar panels to com-

The solar panel arrays on the roof areas of the Panasonic factory complex at Jalan Ahmad Ibrahim.

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plement its diesel generator, which currently fulfils all electricity needs. Tanglin Academy is the first tennis centre in Singapore to introduce clean energy practices, whilst promoting solar education and a healthy lifestyle. Mr Elvin Chee, its business and operations director, shared that “the motivation for the collaboration with Sunseap on the off-grid solar project came from the desire to reduce air and noise pollution created by the diesel generator, and to provide solar energy education to children.” He also mentioned that the academy recognised the importance of influencing the mindset of younger generations from an early age about renewable energy and the environment. Through the use of solar energy, the academy is expected to save 15 to 20 per cent of their energy costs, while reducing their carbon footprint by an estimated 8.3 tonnes per year. This is equivalent to daily carbon dioxide emissions from 500 cars.

INDUSTRY NEWS

NTU to build an offshore integrated system of renewable energy sources

Some of the solar PV panels that are a part of the hybrid microgrid system. Photo: NTU

Nanyang Technological University is building an offshore system that will integrate multiple renewable energy sources such as solar, wind, tidal, diesel, and power-to-gas technologies. The region’s first large-scale offshore power grid system, it will have four hybrid microgrids, occupying over 64,000 square metres of land or roughly about eight soccer fields. The system will be built at Semakau Landfill which is managed by the National Environment Agency (NEA). It will have over 3,000 square metres of photovoltaic (PV) panels, including energy storage systems that are already in operation. The deployment of the first hybrid microgrid was announced in October by Mr Masagos Zulkifli, Minister for the Environment and Water Resources at the Asia Clean Energy Summit, held at Marina Bay Sands.

“I am happy to announce that the first microgrid has just been deployed and it will enable the NEA to power its infrastructure on Semakau Landfill using electricity generated through zero-carbon means. The use of energy storage and microgrid control technologies will allow the landfill to … transition towards renewable energy,” he said. Harnessing nature’s power Built under the Renewable Energy Integration Demonstrator-Singapore (REIDS) initiative led by NTU, the hybrid power grid system will test the integration of solar, wind, tidal-current, diesel, energy storage and power-togas technologies and ensure these energy sources operate well together. REIDS will also deploy three other microgrids on Semakau Landfill to test how well the various solutions can integrate with each other.

Once all four hybrid microgrids are fully built, they are expected to produce stable and consistent power in the megawatt range, suitable for small islands, isolated villages, and emergency power supplies. It will also produce energy amounting to the equivalent of the average energy consumption of 250 4-room HDB flats for a year. Fish hatcheries and nurseries located at Semakau Landfill will be among the first to be powered. NTU Chief of Staff and Vice-President (Research), Prof Lam Khin Yong, said: “The deployment of this first hybrid microgrid is a big leap towards low-carbon electricity production for the nation and the region. As a global leader in sustainability research, NTU is proud to champion this groundbreaking initiative and lead Singapore’s charge in developing practical renewable energy solutions.”

December 2016 THE SINGAPORE ENGINEER

INDUSTRY NEWS

Technip awarded a subsea contract in Malaysia Technip has been awarded a subsea contract by Petronas Carigali Sdn Bhd, a wholly owned subsidiary of Petronas, for the Samarang Redevelopment Project Phase 2 EOR (Enhanced Oil Recovery), in Malaysia.

Under this contract, Technip will manage the engineering, supply, construction, installation and commissioning (EPCIC) of flexible pipelines, as well as that of associated platform I-tubes. The contract will be executed by

Technip’s operating center in Kuala Lumpur, Malaysia and is scheduled for completion in the third quarter of 2017. To find out more, visit http:// www.technip.com/en/press/technipawarded-subsea-contract-malaysia

New Innovation Centres to serve customers better Multi-industry specialist Jebsen & Jessen (SEA) has launched two new regional centres of innovation in Bangkok, under its ingredient business unit, to help customers and principals in the consumer and coating industries bring and adapt products to the South East Asian market faster and more effectively. The innovation centres span a total of 630 square metres and will see 12 dedicated scientists and technicians operating a range of cutting edge analysis and prototyping equipment in the THB 28 million (SGD 1.1 million) laboratories. “Besides having ingredients adapted to specific local needs and palates of South East Asian customers and consumers, we can also provide technical assistance and support within the same time-zone and conduct testing more quickly,” said Mr Marc Deschamps, Regional Managing Director

Mr Marc Deschamps (back row, seventh from left), Regional Managing Director & CEO of Jebsen & Jessen Ingredients poses for a group photo with Jebsen & Jessen (SEA) staff at the opening ceremony of the Coating Innovation Centre. Photo: Jebsen & Jessen (SEA).

& CEO of Jebsen & Jessen Ingredients. He also mentioned that the laboratories can host regional customers for a modern, hands-on training experience. In these new facilities, Jebsen & Jessen Ingredients is now also able to pro-

duce samples and prototypes within the region, conduct batch testing of products as well as to custom-formulate principals’ ingredients for customers, while providing prompt technical support and trouble-shooting.

World’s largest floating solar panel test-bed launched here From now till mid-2017, the world’s largest floating photovoltaic (PV) test-bed will be put through its paces at Tengeh Reservoir. A joint initiative led by the Economic Development Board and national water agency PUB, the investigation seeks to find

out more about the economic and technological feasibility of utilising inland water bodies to host large-scale floating PV systems. The Solar Energy Research Institute of Singapore, located at NUS, will conduct the study and manage the SGD

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11 million, one-hectare plot during this period, with the power generated during the test being used to supplement Singapore’s electricity consumption. For more information, visit http:// news.nus.edu.sg/highlights/11022floating-solar-panels-make-waves

INDUSTRY NEWS

Electric scooter latest addition to growing stable of self-driving vehicles With eyes set firmly on a smart, carlite society, Singapore has tested out self-driving taxis, driverless pods, and self-driving golf carts. Now, another vehicle is set to join the lot â&#x20AC;&#x201C; the self-driving electric scooter. Built by a four-member team from the Singapore-MIT Alliance for Research and Technology (SMART), based at NUS, the 50 kg scooter is able to carry one passenger autonomously for up to five hours, at a maximum speed of 6 km/h. The scooter is able to detect and navigate around obstacles in

its path, slowing down or stopping when necessary. It has a sensor range of 2.5 m forward and 0.1 m at the sides, and works indoors and outdoors. The development team, headed by NUS Associate Professor Marcelo Ang, is working on mapping areas in Taman Jurong, Sembawang and Queenstown in preparation for public trials. For more information, visit: http://techxplore.com/news/201611-self-driving-mobility-scootershown-singapore.html

The autonomous electric scooter and related software were designed by researchers from MITâ&#x20AC;&#x2122;s Computer Science and Artificial Intelligence Laboratory, NUS and the Singapore-MIT Alliance for Research and Technology (SMART). Photo: Autonomous Vehicle Team, SMART Future of Urban Mobility Project

December 2016 THE SINGAPORE ENGINEER

EVENTS

BuildTech Asia 2016 unveils technologies for transforming the building and construction sector Organised by Sphere Exhibits and hosted by the Building and Construction Authority (BCA), BuildTech Asia 2016, the sixth edition of the annual trade show for the building and construction industry, was held from 18 to 20 October 2016, at Singapore EXPO, as part of the Singapore Construction Productivity Week 2016 (SCPW 2016). At Build-Tech Asia 2016, over 100 exhibiting brands showcased the latest productive and cutting-edge technologies covering construction machinery to architectural and building solutions. Robotics and Internet of Things (IoT) technologies were also on display, alongside 3D concrete printers as well as immersive Big Data and Virtual Reality applications. BuildTech Asia 2016 attracted around 7000 visitors from 32 countries, which represents an increase of 35% over the figure recorded for last year’s event. Held from 18 to 21 October 2016, the key events at SCPW 2016 included, besides BuildTech Asia, Build Smart Conference, Skilled Builders Project, the inaugural SCAL Productivity Innovation Competition and Awards, the Experiential Workshop, as well as the Productivity Workshop, Productivity Challenge and Productivity Race to engage tertiary students on construction productivity concepts. Mr Lawrence Wong, Minister for National Development and Second Minister for Finance, graced the opening of SCPW 2016. In a speech made on the occasion, he announced that the Singapore government is committed to helping firms harness the full potential of Building Information Modelling (BIM) and Virtual Design and Construction (VDC), to improve collaboration and enhance the construction management process.

Mr Lawrence Wong, Minister for National Development and Second Minister for Finance, was the Guest-of-Honour at the opening of the Singapore Construction Productivity Week 2016.

Thirty-five key technologies, under seven R&D clusters, were identified, that would enable the built environment sector to sustain productivity improvements in the long term.These areas include Design for Manufacturing and Assembly (DfMA), automated equipment and robotics, Infocomm Technology, BIM and VDC, 3D printing, advanced construction materials and productive solutions for civil engineering works. Additionally, BCA’s announcement on a S$2 million funding for four research projects will focus on DfMA solutions that enable the shifting of much of the on-site construction to off-site prefabrication and automation, in a factory environment, as well as improving integration across the construction value chain. Strengthening knowledgebased platforms As Singapore is in a leadership position, as a hub for developing Southeast Asian markets such as Indonesia, India, Malaysia,Thailand and the Philippines, BuildTech Asia plays a facilitation role in knowledge-sharing. Some 100 trade delegates joined site visits to the BCA Skylab, a state-of-the-art rotatable test facility pivotal to developing innovative energy-efficient building technologies, as well as to a project site for a residential estate, that incorporates the use of produc-

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tive technologies such as Prefabricated Prefinished Volumetric Construction (PPVC). Property developers are creating customer-centric one-to-one (O2O) experience through sensor technology, Internet of Things, cloud, RFID technology, social media and data analytics, to develop touchpoints with consumers. The inaugural Building Internet of Things Asia (B-IoT Asia) Conference, featuring a panel of speakers from the region, demonstrated how such knowledge and technology can be applied and how buildings can be constructed to cater to evolving technology requirements. Delegates engaged in deep discussions on how to apply technologies like Big Data and IoT to the building and construction sector. The Environment Sustainability Conference featured presentations on how to think, build and operate ‘Green’. Speakers showed how BIM can pave the way towards sustainable building; how machine-based learning contributes to energy management; and how to design with a view to achieving Green Mark 2015 certification. The conference also discussed how acting sustainably while constructing a building was as important as creating a building that is inherently sustainable. Productive practices in innovative construction Innovation and technology have strong impact on a company’s productivity. The inaugural SCAL Productivity and Innovation Awards (PIA) 2016 were presented at BuildTech Asia 2016. PIA 2016 is an industry-led initiative, designed to raise productivity in the construction sector through a ground-up approach for innovative ideas that aim to generate significant improvements at the workplace.

EVENTS Three winners were announced at the Environmental Sustainability Conference, held in conjunction with BuildTech Asia 2016. The winners were: • Gold - Lian Soon Construction Pte Ltd, for Innovative Drain (iDrain), a durable reusable ECM drain • Silver - Samwoh Corporation Pte Ltd, for Productive and Green Solution for Pavement Retexturing & Spillage Removal • Bronze - S C Ang Consortium Pte Ltd, for Global Navigation Satellite System (GNSS) for Piling Projects Forging partnerships and collaborations in SMART construction Besides exploring the latest technologies and materials, delegates and exhibitors fostered new business relationships as well as commercial partnerships at BuildTech Asia 2016. Visitors saw a wide range of new innovations that could help them improve construction productivity and reduce manpower expenses, at the Public Sector Co-ordinated Pavilion, amongst country pavilions and company exhibits. BuildTech Asia 2016 also provided a conducive springboard for exhibiting companies to launch new products, services and technologies into the local and international markets. Various industry players announced new initiatives and partnerships aimed at elevating construction productivity in Singapore and the region. Bointec, a Taiwanese company, launched its latest IoT product. FINALCAD, a Paris (France)based provider of mobile construction apps announced a US$20 m funding to help expand its suite of services in Southeast Asia. This new round of funding aims to assist the development of new technology such as object recognition, predictive analytics and augmented reality, and complements the company’s existing mobile apps.

Build-Tech Asia 2016 featured over 100 exhibiting brands and attracted around 7000 visitors from 32 countries.

THE SINGAPORE ENGINEER December 2016

EVENTS

Singapore hosts the ITA Tunnelling & Underground Space Awards 2016 The International Tunnelling and Underground Space Association (ITA) held the second edition of the ITA Tunnelling Awards event at Marina Bay Sands, Singapore, recently. The objective of the awards is to recognise and reward the most ground-breaking achievements and innovations in underground infrastructures.

PROJECT AWARDS MAJOR PROJECT OF 2016 (EXCEEDING €500 MILLION) New Guanjiao Tunnel on Qinghai-Tibet Railway (China) The New Guanjiao Tunnel is a key component of the second line of the Xining-Golmud section of the Qinghai-Tibet Railway, with a total length of 32.690 km. Electrified freight and passenger trains travel through the two-set, single-track tunnel, with a design speed of 160 km/h.The tunnel has an average elevation of 3400 m. After overall consideration, the borehole blasting method was chosen. The construction began on 6 November 2007 and the tunnel was opened for operation on 28 December 2014.The total investment is 4.96 billion RMB. TUNNELLING PROJECT OF THE YEAR 2016 (FROM €50 MILLION TO €500 MILLION) Downtown Line Stage 3 Contract 937 Construction of Fort Canning Station and Tunnels in Singapore (Singapore) As Singapore’s underground space becomes more congested with various competing needs, such as underground basements, utilities tunnels and metro infrastructures, the construction of new underground metro lines has correspondingly become more challenging and complex, and this results in the need to push the boundaries of engineering. This tunnelling project encountered many challenges such as cutter head interventions to remove foundations of buildings, close proximity to national monuments and in-service metro lines with only 1 m separation. Tunnelling at such close proximity to’live’ tunnels, which carry hundreds of thousands of commuters daily, poses exceptionally high risk.This project has since been suc-

INDIVIDUAL AWARDS LIFETIME ACHIEVEMENT Dr Martin Herrenknecht Dr Martin Herrenknecht received the Lifetime Achievement Award for his remarkable contributions in tunnelling. Dr Herrenknecht studied at the Konstanz University of Applied Sciences in Germany, from where he earned his diploma in 1964. He founded his own company in 1975, specialising in tunnel boring machines. In 2010, Herrenknecht AG, his company, was recognised for drilling the largest tunnel in the world. He also took part in the Eurasia Tunnel Project, which was selected as the Major Project of the Year 2015.

Dr Martin Herrenknecht (left) receives the Lifetime Achievement Award from ITA President, Prof Tarcisio Celestino.

cessfully completed with no disruption to any community partners. OUTSTANDING TUNNELLING PROJECT OF THE YEAR (UP TO €50 MILLION) Chongqing Hongqihegou Metro Station (China) The Chongqing Hongqihegou Metro Station is an interchange station con-

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YOUNG TUNNELLER OF THE YEAR Mr Derek Eng Mr Derek Eng studied Civil Engineering and professionally trained in the field of tunnelling. He currently works as an Assistant Manager in the tunnel department for MMC Gamuda KVMRT (T) Sdn Bhd, Malaysia, the Main Contractor for the underground stations and tunnel constructions for mass rapid transit projects. Derek's career has moved beyond the technicalities of tunnelling, to focusing a lot on providing professional training related to tunnelling and inspiring young school leavers to take up engineering as the career of choice.

Mr Derek Eng

necting Line 3 and Line 6 in Chongqing, China. The station is located under the main road to the airport, in the bustling area of Chongqing, where there are many buildings around. It is built with moderately weathered sandstone and moderately weathered sandy mudstone. The minimum cover thickness of the overburden strata of the project

EVENTS is 8.6 m, and the rate of overburden to span is 0.4. Its maximum excavation section is 760 m. The concept of the ‘inner rocks’ and the ‘inner rocks supporting’ tunnelling method was put forward in the project. The whole tunnel section is divided into four drifts.Two are on the top and another two are at the bottom which had to be excavated. In this way, four drifts could be driven simultaneously. By using the inherent bearing capacity of ‘inner rocks supporting’, the horizontal and vertical temporary support of the tunnel were saved. Moreover, the ‘time-space’ effect was controlled precisely for the safety of the force transmitting between primary support and final lining. RENOVATION/UPGRADING PROJECT OF THE YEAR Vauxhall Station Upgrade Project (UK) London underground’s (LU) Vauxhall Station Upgrade will soon provide step-free access for tube users. The project is led by Bechtel Ltd, as the Main Contractor, and designed by Gall Zeidler Consultants, in a designbuild contract, with tunnelling works carried out by Joseph Gallagher Ltd. The project team changed the reference design to a complete SCL design, to provide a more efficient construction programme and reduce ground movements. A more economical reinforced concrete collar was designed, rather than traditional steel lintel beams installed to support new openings in the existing platform tunnels with steel props. These eliminated health and safety risks associated with the installation of heavy steel framing and encroachment onto platform clearance. From the design phase, the project team engaged the owners of the St George’s Wharf, a high-rise building next to the site, and integrated a design review by their appointed engineer. A potential damage assessment (PDA) and real-time instrumentation and monitoring programme formed the integral part of the assurance process. The project has successfully increased existing station capacity

without fundamentally altering the operational station. A LU representative confirmed the above. The value added was in the elimination of utility relocation, which cut the construction duration by at least six months. Early third-party outreach efforts led to a smooth approvals process during the design and construction phases. The SCL approach aided to the nearly €12 million in total cost savings. TECHNICAL INNOVATION OF THE YEAR Large diameter shield tunnelling in pure sands with hybrid EPB shield technology (Brazil) The shield-driven tunnel of Metro Line 4, in Rio de Janeiro, Brazil, has an approximate length of 5.2 km. The excavation was performed using a hybrid earth pressure balance shield with an excavation diameter of 11.51 m, and passed through complex geology that included a long stretch of pure sand bounded by two stretches of hard, highly abrasive rock. Considerable reduction in materials, for conditioning consumables, and in power consumption, was achieved with this hybrid EPB technology. ENVIRONMENTAL INITIATIVE OF THE YEAR The Emscher Project - Back to Nature! (Germany) The Emschergenossenschaft in Essen, Germany, is currently implementing one of the largest environmental projects in the world, namely, the restructuring of a whole river system. This system has been used as an open wastewater transport system for more than 100 years as a consequence of extensive coal mining activities. After 2020, the whole river Emscher, (total catchment 865 km2) will be transporting clean water again. To reach this target, it will be necessary to build a large 51 km long, underground sewer from Dortmund to Dinslaken, through a densely populated conurbation. This central Emscher sewer will have diameters varying between 1600 mm and 2800 mm, at depths between 25 m and 40 m below the surface. Shafts will be constructed at up to 1200 m intervals. Three large

THE SINGAPORE ENGINEER December 2016

pumping stations, up to 48 m in diameter, will lift the wastewater from the Emscher sewer into the existing treatment plants. The largest section of the Emscher interceptor is called Lot 30. In early 2012, its construction was awarded to Wayss & Freytag Ingenieurbau. The contract requires the construction of about 47 km of sewer tunnels. In addition to the tunnels, more than 100 construction pits have to be excavated, from which the tunnels will be driven by pipe jacking. In October 2015, tunnelling was successfully completed, ensuring that upon project completion, the whole river Emscher will be free of wastewater and can be returned to its natural state with ecologically redesigned rivers and new recreational areas. SAFETY INITIATIVE OF THE YEAR ABSIS (Activity Based Safety Improvement System) (Singapore) The Cable Tunnel project involves the construction of a 35 km long tunnel, with an average depth of 60 m, to house the 400 kV and 230 kV transmission cables. ABSIS was introduced in this project as a systematic approach to address safety issues in various critical tunnelling activities. It is a platform where work activities are captured in a video. By viewing the video footage of themselves carrying out the works, the workers, without any language barriers, are able to see the safety lapses they are responsible for, as well as the good practices they achieve and can also adopt. INNOVATIVE USE OF UNDERGROUND SPACE Jurong Rock Caverns (Singapore) Jurong Rock Caverns (JRC) is located on Jurong Island and is Southeast Asia’s first commercial rock caverns facility for the storage of liquid hydrocarbons such as crude oil and condensate. Located 150 m below the ground, JRC is able to optimise land use by saving up to 60 ha of above-ground land, whilst ensuring safety and security of the products in storage, and reinforcing Singapore’s position as a leading energy and chemicals hub.

COVER STORY

HDB project demonstrates safety in design and construction SkyTerrace @ Dawson won a DESIGN AND ENGINEERING SAFETY EXCELLENCE AWARD, in the RESIDENTIAL CATEGORY, at BCA AWARDS 2016.

SkyTerrace @ Dawson comprises five 40- to 43-storey high residential blocks. Image by Housing & Development Board.

INTRODUCTION Located adjacent to the Alexandra Canal Linear Park,SkyTerrace @ Dawson comprises five 40- to 43-storey high residential blocks. The Housing & Development Board (HDB) project was completed in early 2015. The five blocks, which house 758 units, are linked to a four-storey carpark podium and six sky bridges, two of them linking Blocks 92 and 93 (at the 33rd storey and the 18th storey levels), two linking Blocks 89 and 90 (at the 34th storey and 19th storey levels) and two linking Blocks 90 and 91 (at the 28th storey and 13th storey levels). There are two levels at each sky bridge. The top level is a sky garden

accessible to the public, whereas the bottom level is a maintenance deck accessible only to maintenance personnel. The two sides and bottom of the steel structure are clad with galvanised steel mesh. The bridge structure comprises 3D trusses on the sides, RC slabs on the top level and a steel platform at the bottom level. There were several challenges that the project team had to overcome for the successful completion of the project. These include the following:â&#x20AC;˘ Designing of the structural framing of the tower blocks, due to the different layout for every floor, loft and split level - the tower blocks are made up of four dwelling units

THE SINGAPORE ENGINEER December 2016

Loft / double volume space

COVER STORY

The modular effect was created every three floors. It repeated itself so that it can be constructed efficiently and gives the effect of greater height than that of each floor.

Sixth-storey floor plan (typical Plan A)

on each floor, with the lift core and staircase at the centre of the building. • Designing the precast concrete, to create a 3D modular effect for the façade, with every three floors of units combining to form a module. The module is then repeated along the height of the block. • Designing of sky bridges which act as refuge floors and sky terraces. The sky bridges straddle between the five blocks, on two levels of each block.

STRUCTURAL DESIGN EMPHASISING SAFETY

Location of sky bridges

THE TOWER BLOCKS Due to the different layout of each floor, the consultant’s design team faced the difficulty of placing columns inside the unit. After discussion, the consultant’s design team decided to place the column at the perimeter of the unit, to avoid transfer columns and transfer beams, in accordance with the HDB’s structural requirements and also to increase the lateral and rotational rigidity. There are two levels on each sky bridge.

December 2016 THE SINGAPORE ENGINEER

COVER STORY

Structural layout plan (2nd storey)

All perimeter beams and columns were precast, as no scaffoldings were allowed for the entire construction stage. Internally, all the beams and slabs were also precast to reduce temporary supports, dust and noise at site. Typical module In order to create the effect of a threefloor module system for the faĂ§ade, the consultantâ&#x20AC;&#x2122;s design team needed to consider how to split and join the individual precast components together. The team needed to consider the construction sequence and its constructability. A 3-D model for each module was created by assembling the precast components together, to study the constructability and the safety aspects. In addition, a prototype demonstration model was created, to observe the visual impact and the potential risk during installation of precast components at the construction stage. Before erecting of any new precast component, the contractor had to submit the method statement, to ensure that the component could be installed safely.

The three-floor module system

Precast components were used in the construction of the blocks.

THE SINGAPORE ENGINEER December 2016

COVER STORY

Lifting the main bridge

Synchronised hydraulic strand jacks were used to lift the skybridges which were assembled on the ground.

SKY BRIDGE CONSTRUCTION Various schemes were studied for the construction of the sky bridges. Eventually, the consultant’s design team decided to assemble the steel structure on the ground, using BONDEK structural steel decking together with a safety barrier, and lift it up by using synchronised hydraulic strand jacks. These jacks were installed on I-beams that were temporarily fixed on the roofs. As the external profile of the unit protrudes unevenly, the sky bridges were split into three portions - two cantilevered portions and the main bridge portion. The two cantilevered portions are located at the left and right recessed parts of the building surface and therefore could be easily installed from the edges of the respective floors. These two portions were installed using a tower crane and secured by temporary bracing. The temporary hoisting beam was installed on the roof to lift the main portion into position, using the hydraulic strand jacks, and it was then bolted to the two cantilever portions. Information was obtained from the Meteorological Service to ensure that the weather on the day of the lifting was good and there would be no rain

or strong winds that could cause the steel structure to sway, during the lifting operations.

QUALITY IN DESIGN, DETAILS AND SPECIFICATIONS The lateral stability of the building was checked, based on the static wind load, notional load, dynamic wind load and ground acceleration (0.03 g). The maximum deflection at the tips of the building was 72 mm (dynamic wind load) which is less than the allowable value of H/500 = 240 mm. In terms of the comfort level, the peak acceleration at the tip of building was 5.7 milligrams which is less than the allowable value of 20 milligrams. Therefore, the building is able to resist the lateral loads, in terms of deflection and comfort level. The lateral movements at the level of the sky bridges were monitored every month and the results were checked against calculated values. STRUCTURAL SYSTEM Superstructure A semi-precast structural system was chosen, comprising the following: • Cast-in situ concrete columns and beams mainly, precast concrete columns and beams where exposed • All load bearing walls - precast concrete lift walls / staircase walls / household shelter walls • Precast concrete volumetric house-

hold shelter with hollow-core wall system with infill concrete and reinforcement • All structural elements made of reinforced concrete for the 4th storey and below • Slab using precast prestressed concrete plank with cast in-situ topping supported by precast concrete / reinforced concrete beams • Sky bridge (structural steel truss) - 2.2 m deep main truss supported by pot bearings. - Main sky bridge has a weight of approximately 25 t. - Cantilever truss connected to wall and column. - 130 mm thick reinforced concrete slab with BONDEK on steel truss, on the top level. - Maintenance catwalk on the bottom level. - Planter boxes on the top chord of the truss. Design loading • Dead load - the unit weight of materials used for calculation of dead loads, as given in BS6399. • Superimposed dead load - finishes, planters, partition walls, M&E installations etc. • Live load - uniformly distributed loads used in the design are generally based on BS6399 and HDB requirements. • Wind load - wind loads acting on the structures are calculated using coeffi-

December 2016 THE SINGAPORE ENGINEER

COVER STORY cients from BS6399 Pt2:1995 and are based on a design mean speed of 22 m/s and HDB requirements. • Robustness - the RC core walls and columns were checked for robustness by applying a notional load of 1.5% of the characteristic dead load acting horizontally at each level on the structure as required under Cl.3.1.4.2 of CP 65:Part 1:1999. Foundation system The project area lies within the geological demarcation called Jurong Formation.The area covered is wide, with thin to thick layers of clayey/silty sand and sandy silt, silt and clay, which are decomposed or completely weathered products of underlying sedimentary rocks such as mudstone, siltstone, sandstone and thin layers of peaty clay from the Kallang Formation. Bored piles of diameter 500 mm to 1600 mm were installed. The pile depths vary from 20 m to 34 m and are socketed into moderately weathered (G3) rock or SPT>100 soil. A pile raft has been used for the majority of the internal columns, as building loads are large and the piles would have been too close to one another.

DESIGN FOR SAFE OPERATION AND MAINTENANCE MAINTENANCE OF FAÇADE • There is a reachable gondola all around the building, for maintenance purposes. • Waste stacks are designed for easy inspection/maintenance and are accessible. • There is provision for fixings or attachments for cyclical maintenance equipment, eg a gondola for maintenance of external walls of the building. • All parts of the building are accessible for periodic building inspection and maintenance work. • Sanitary pipes and lightning conductors are not embedded in the slabs, beams, columns or RC walls. • RC structures and piles are not used as lightning conductors or used as earth electrodes. 26

Maintenance catwalk on bottom chord

MAINTENANCE OF SKY BRIDGES An additional inspection deck was designed to facilitate future inspection of the sky bridges and bearings.

CONSTRUCTION QUALITY AND SAFETY NO EXTERNAL SCAFFOLDING All external beams, slabs and columns were designed as precast structures, so that no external scaffoldings are required. All finishes were completed off-site and fixed in place. INSTALLATION OF SKY BRIDGES When the lifting operation approached the final level, four I-beams of the cantilever trusses were found to be slightly out of position, resulting in an obstruction to the installation. The affected I-beams were immediately trimmed to facilitate the installation of the main bridge. The affected I-beams were rectified subsequently. To avoid similar problems in subsequent lifting operations, the four secondary members were installed only after the main bridge was lifted. Improvement in the lifting process As part of the lower bridge, the twoedge portions were installed before lifting the main bridge. Care was taken to ensure that the joints in the main bridge being lifted did not clash with the joints of the lower bridges.

THE SINGAPORE ENGINEER December 2016

Chain blocks were used to pull the upper bridge away from the joints of the lower bridge. This process took more than an hour, in order to clear the obstruction of both the top and bottom chords of the joint. To cut short this process during subsequent lifting, the upper bridge was offset from the actual position to avoid clashing with the lower bridge joints. After lifting to the final level, chain blocks were used to pull the lifted bridge into the final position, for bolting. IMPROVEMENTS IN SAFETY • Ensuring that all the lifting crew members have attended the basic Safety Instruction Course for the project. • Improving the lifelines installed on the bridge/and from the building, for easy and safe use by the lifting crews. • Installing additional lifelines that are adequate for crews to work on the bridge, whilst avoiding the sharing of lifelines by the crews. • Installing rigid or firm tag lines to secure the bridge and not using lifelines to control the bridge during the lifting process. • Improving the access /platforms to be used during the lifting process and ensuring all the areas necessary for the crews to access or work on the bridge are provided with safe and stable access / platforms.

COVER STORY specifications. Random samples of the materials were sent to an accredited laboratory for testing and the test reports were sent to the consultant to interpret the results and take appropriate action. QUALITY CONTROL Work progress was monitored by site staff and recorded in the minutes. Site staff signed off inspection forms whenever the contractor completed installation works or after each inspection. The site staff ensured that the tools and instruments are used by the contractor correctly. Regular site walks were undertaken by the consultants, site staff and the contractor, to identify non-conformance and design issues.

Cantilevered I-beams form part of the sky bridges.

• Teaching the lifting crews on the proper use of the safety harness and emphasising the significance of the safety equipment issued to them. Giving proper training on how to use it, if necessary. • Emphasising to the workers on the safe work practices to ensure the safety of each and every crew member involved in the lifting process. • Providing proper access to ensure the safety of the workers when crossing from the building to the bridge and vice versa. Ensuring all necessary personal protection equipment are also utilised correctly. • Ensuring that all the necessary components of the scaffolding / access are provided. • Educating the workers on the safety aspects when working on the scaffolding /access, such as avoiding short cuts and improper access to avoid any untoward incidents. • The use of a lifting system for sky bridges eliminates the requirements of building falsework at high levels. Façade and aluminium windows • No external scaffolding during the construction stage.

• Monitoring of work, with weekly technical meetings with the contractor. • Checking design details to ensure compliance with the design requirements (modularity) and technical specifications, authorities’ regulations and HDB standard details. • Samples sent by the contractor, for testing, to ensure compliance for water tightness, safety and loading. • Construction of a two-storey precast façade mockup, as a visual reference. QUALITY ASSURANCE Selection of materials was based on the compliance with the Codes of Practice, specifications and user requirements, as well as on considerations of functionality, cost, safety, durability, aesthetics, maintenance and availability. Approvals were based on compliance with specifications as well as on whether the materials came from an approved source. When taking delivery of the materials and storing them, the considerations were whether they were approved types of materials and were in good condition. The materials were then properly stored and protected. The testing of the materials sought to ensure their compliance with

PUBLIC SAFETY

Noise management measures were implemented to reduce inconvenience to the occupants of buildings in the neighbourhood. These included a cut-off time for stoppage of noisy work, so that there is no disturbance at night. Good workplace safety and health measures as well as safety management were adopted, as were good housekeeping, pest control and Earth Control Measures (ECM).

PROJECT CREDITS Qualified Person Er. Koh Boon Liang

Civil & Structural Consultant Ronnie & Koh Consultants Pte Ltd

Builder Sunhuan Construction Pte Ltd

Developer Housing & Development Board

Architectural Consultant SCDA Architects Pte Ltd

All images by Ronnie & Koh Consultants Pte Ltd, unless otherwise stated

December 2016 THE SINGAPORE ENGINEER

HEALTH & SAFETY ENGINEERING

The collapse of table formworks at a construction site - a case study by Dr Goh Yang Miang, Yee Yew Seng, Er. Liau Wai Kun and Jonathan Tan, Health and Safety Engineering Technical Committee, IES Twenty-four table formworks collapsed at a construction worksite in a coastal area in Singapore, on 3 August 2016. Fortunately, no one was injured as a result of the collapse. The Ministry of Manpower was notiďŹ ed of the incident. One of the parties involved in the project felt the need to share the lessons learned, so as to prevent similar incidents in the future. Accordingly, they invited members of the Health and Safety Engineering Technical Committee of IES to visit the site and learn about the incident. This article highlights the risk of table formwork collapsing, especially in windy areas. If applicable, designers and contractors should identify this hazard in their design risk review and risk assessment, and implement the relevant risk controls to prevent such incidents from happening in their projects. Background The building under construction was more than 40 m tall at the point of the incident. On the night of 2 August 2016, a total of 27 formworks were lifted and stored on the top level of the building, to facilitate dismantling during the following day shift. According to site personnel, the table formworks could not be stored on the lower levels, due to site constraints. Each of the table formworks was about 10.2 m tall. The lifting was completed at about 5 am on 3 August 2016, the day of the incident, after which, the night shift workers ended their shift. At about 5.50 am, the workers found that 24 of the formworks had collapsed. Workers reported strong winds, prior to the collapse. This was corroborated by the meteorological report on wind speeds in the vicinity, between 5 am and 6 am on 3 August 2016. The cause of the incident Based on observations from the site visit and the photos provided, the formworks seemed to have collapsed in the same direction. At the same time, the formwork bracings and base plates seemed to have remained largely intact and damage was probably due to the collapse. Based on the information supplied by the site personnel, strong winds appeared to be the most likely direct

The scene of the incident on the morning of 3 August 2016

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HEALTH & SAFETY ENGINEERING

•

• • •

Wind speeds between 5 am and 6 am

cause of the collapse.The meteorological report showed that the maximum wind speed near the worksite, between 5.50 am and 6 am (estimated time of the collapse), was 46.5 knots (23.9 m/s) and the average wind speed was 40.1 knots (20.6 m/s). This is significantly higher than the average monthly surface wind speed of 2.5 m/s in August 2016 (http://www.weather.gov.sg/climate-climate-of-singapore/). As can be observed from the time series plot of average and maximum wind speed, the wind speed rose suddenly at about 5.35 am. A rough calculation was conducted by a Professional Engineer (PE), in accordance with CP3: Chapter V: Part 2: 1972, on a pro-bono basis. Using parameters provided by site personnel, it was found that the factor of safety against overturning was less than 0.7. The key overturning moment was due to the wind pressure acting on the free-standing formworks on the windward side. The wind pressure was magnified due to the height of the formwork (10.2 m). Other factors contributing to the overturning include the uplift, wind drag and the lack of stabilising moments. Once the formworks on the windward side collapsed, they triggered a domino effect, leading to the collapse of the 24 formworks. Implications for design and construction This incident should remind the industry of the need to consider stability issues for formwork and other tempo-

rary structures. It was fortunate that site personnel stored the table formworks away from the building edges and the formworks did not fall off the building. In addition, the collapse occurred when there were no workers in the vicinity. However, a recurrence of such an incident can easily lead to multiple fatalities and severe injuries. With the implementation of the Workplace Safety and Health (Design for Safety) Regulations on 1 August 2016, stability of temporary structures must be considered during design for safety reviews, more specifically, during GUIDE-3: Pre-construction review. During the review, tall formworks should be avoided, whenever possible, through pre-fabrication or other measures. If formworks are used, the stability of the formwork has to be considered in sufficient detail, including the possible effects of wind and other lateral loads. It will be necessary to have detailed discussions with the suppliers of system formwork, to understand possible measures to prevent instability. It is also recommended that suppliers of formwork systems should provide specific instructions to their clients on ways to prevent similar incidents from happening. Other possible risk controls during construction include: • Careful site and work planning, taking into consideration the possible hazards at different stages of construction. In this particular incident, the location for dismantling the

formworks was not suitable, as the tall, free-standing table formworks were stored at a substantial height and the site was in a coastal area, where the effects of wind become more significant. Reducing the exposure of free-standing table formwork to effects of wind, by dismantling them as part of the lifting process and as soon as possible. Weighing down vertical footings of formwork, by means of anchorage or temporary counterweights. Attaching outriggers to vertical footing of formwork. Providing for diagonal and horizontal bracing, to connect the table formworks to form a more rigid integrated structure.

Conclusions Construction work will always be constrained by many factors like time, cost and space. Thus, it will be more effective, if hazards are considered upstream during design, so that inherently safer methods of work can be implemented during construction. Nevertheless, equipment suppliers and contractors have to conduct detailed risk assessment to identify and implement suitable risk control measures, to ensure that work can be conducted safely. More fundamentally, all stakeholders must see safety as an important aspect of their work. If not, safety regulations, risk assessment and safety measures will have no effect at all. It must be noted that this article was written, based on information collected informally, and the authors do not have the authority and resources to verify all the details about the incident. Nevertheless, this article presents useful information and hopefully it will help to prevent such incidents. References Circular on Safety Requirements for Formwork Structures https://www.wshc.sg/files/wshc/upload/ cms/file/20130131-55 Safety Requirements for Formwork Structures.pdf Workplace Safety and Health Guidelines - Design for Safety https://www.wshc.sg/files/wshc/upload/cms/file/WSH_Guidelines_Design_for_Safety(1).pdf

December 2016 THE SINGAPORE ENGINEER

HEALTH & SAFETY ENGINEERING

Design and testing of a crash bollard system by Ang Choon Keat, Lim Siew Fern and Lim Jiunn Jie, Prostruct Consulting Pte Ltd, Singapore A crash bollard system is a type of physical security measure used to prevent forced entry by vehicles as well as to provide adequate stand-off distance between the target and a VehicleBorne Improvised Explosive Device (VBIED). Thus, the design of a crash bollard system will have to take into consideration high energy vehicle impacts and the need to minimise postimpact penetration. This article brieďŹ&#x201A;y describes the design objectives, code provisions and methodologies related to designing and testing of a crash bollard system. Introduction Terrorism remains a serious threat in the world today. A terrorist attack is a very disruptive force which can destabilise the normalcy and unity of a society. The tactics of terrorism nowadays are getting more diverse, as a result of the relative ease of access to chemicals used to make explosives. Attacks can be made by individuals such as suicide bombers, or by vehicles - the latter is becoming more common in the wake of recent terror events. In the recent 2016 Nice attack in France, a cargo truck was deliberately driven into crowds, resulting in the deaths of close to 100 people and injuries to nearly 450. Another vehicle, driven by a suicide bomber hit a shopping area in Baghdad, in July 2016, causing hundreds of casualties. Therefore, protection against vehicle-borne explosive threats and vehicle impact threats has developed into an important requirement. A combination of security measures could be employed to protect the building from these attacks. It would involve active measures covering access control, security screening and surveillance, as well as passive measures such as barriers and bollards. Stand-off distance is one of the most effective ways to reduce the blast effects of a VBIED. This can be accomplished by designing blastresistant structures and/or vehicle security barriers (VSBs), to provide a hardened perimeter around the building. This would prevent or deter unscreened vehicles from approaching too close to a building by keeping

them at a certain distance from the building. It can also mitigate the blast effects if a vehicle bomb is detonated at the perimeter. Crash bollards There are many barrier options that can be considered, when designing VSBs to protect against a VBIED. Typical designs consist of concrete mass barriers, cable barriers, bollards, crash gates etc. A crash bollard is a barrier system which is commonly used through-

out heavy industries and in building management, to protect assets. They usually consist of a steel post, either anchored to concrete, buried in the ground, or secured by a locking system, to protect the surrounding foundations when a bollard is struck. Crash bollards can be of a permanently fixed type or of a removable type that enables them to be inserted or removed from base frame sleeves, to facilitate vehicular access.

Figure 1: Crash bollards.

Figure 2: Fixed crash bollard system

THE SINGAPORE ENGINEER December 2016

Figure 3: Removable crash bollard system

HEALTH & SAFETY ENGINEERING Designation

Dynamic Penetration Rating

≤1 m (3.3 ft)

1.01 to 7 m (3.31 to 23.0 ft)

7.01 to 30 m (23.1 to 98.4 ft)

30 m (98 ft) or greater

V/7500(N2)/80/90:0/1.2 V

7500

(N2)

1.2

Vehicle

Test Weight of Vehicle (shown in Kg)

Vehicle Class

Speed of Vehicle (shown in KPH)

Angle (angle at which the vehicle hit the barrier)

Penetration of Vehicle (shown in metres)

Dispersion (debris dispersion shown in metres)

Table 1: Classification of penetration ratings

Table 2: Interpreting the PAS 68 Classification Code

Test standards Several codes and guidelines have been developed to assist in the testing and certification of crash barriers. ASTM F2656-07 ‘Standard Test Method for Vehicle Crash Testing of Perimeter Barriers’ is an accredited test method which provides a structured procedure to establish a penetration rating for vehicle perimeter barriers subjected to vehicle impacts. The test standard designates six types of vehicles and four different test speeds as the impact conditions, and assigns corresponding penetration distances as classification ratings for the tested VSBs. The classification of penetration ratings are presented in Table 1.These ratings are based on the measurements of the extent to which the test vehicle penetrates or vaults over the reference point of the barrier. British Standards Institute (BSI) also published PAS 68 which has become the UK’s standard and specifications for vehicle security barriers tests. The test standard and classification code rates the crash barrier, based on information such as vehicle mass, test speed, impact angle, penetration and dispersion of major debris. . Table 2 depicts an example of interpreting the classification code.

in crashworthiness and vehicle barrier design applications. It can analyse the dynamic response of structures by employing an explicit time integration methodology that accounts for large deformations, non-linear material behaviour and contact separation behaviour, among many other specialised features. Using LS-DYNA to simulate the crash impact not only helps us to understand the response behaviour of the crash bollards, it also aids in optimising the design, in order to create a cost-effective specimen for physical testing in the validation stage. Figure 4 shows a LS-DYNA model simulating a real crash test scenario created by a 6,708 kg medium-duty truck impacting a triple crash bollard assembly. The test vehicle impact speed was 48.76 km/h at normal angle to the bollard assembly, as stated

A design approach Analysing the dynamics of a vehicle impact process is complicated, as it tends to result in highly non-linear, inelastic and dynamic engineering behaviours. To assist in the design, we have used LS-DYNA as a design tool for the crash bollards system. LS-DYNA is a finite element analysis (FEA) software that is widely used

Figure 4:Truck vehicle (6,708 kg) impacting the centre of a bollard system at 48.76 km/h

Figure 5:Tow tug (70,000 kg) impacting a bollard system at 30 km/h

in the project requirements. The next section of this article presents the comparison of data between the actual ASTM F2656 crash test and the simulation model. Figure 5 shows another LS-DYNA model detail, of a bollard system design under impact from a 70,000 kg tow tug travelling at 30 km/h. The bollard system was later subjected to tests based on ASTM F2656. Testing and model validation During the full-scale vehicle crash tests, conducted in accordance with ASTM F2656-07, on the vehicle modelled in Figure 4, a series of test data was recorded, such as vehicle impact velocity, vehicle acceleration, barrier deformation and vehicle penetration. Accelerometers were mounted on the test vehicle, to record the vehicle deceleration profile during the vehicle impact. Real-time video cameras and highspeed cameras were also deployed, in accordance with the requirements of the impact test standard, to capture the impact sequence, vehicle and bollard assembly response. Figure 6 compares the sequential snapshots taken at distinct times, for the crash test on the above vehicle and the numerical simulation. Figure 7 compares the vehicle velocity-time plot and bollard displacement versus time plot, from the crash test results, with the numerical simulation. Based on the qualitative and quantitative comparisons, we observed that there is a reasonable match, with minor deviations, between the actual field test data and the outputs from the finite element vehicle model.

December 2016 THE SINGAPORE ENGINEER

HEALTH & SAFETY ENGINEERING Conclusions Crash bollards are an effective security barrier measure to deter unscreened vehicles from accessing a protected site. Designing and testing of a crash bollard system before installing it is therefore essential to ensure that the bollard system is able to resist the impact loads and protect the desired assets. During the design-

ing process, utilising LS-DYNA as an analysis tool enabled us to visualise the structural response and failure mechanisms during the crash impact, which may have otherwise been overlooked if traditional static analysis methods are used. It also aids in optimising the design of the bollards and finalising the prototype product to be tested, effectively saving expense and time.

References [1] Paul Forman et al: ‘Vehicle-borne threats and the principles of hostile vehicle mitigation’, Blast effects on building, 2nd Edition, 2009. [2] UFC 4-022-02 (8 June 2009). Unified Facilities Criteria (UFC): ‘Selection and Application of Vehicle Barriers’. [3] ASTM F2656-07. Standard Test Method for Vehicle Crash Testing of Perimeter Barriers. [4] Joseph M Dulka et al: ‘Analysis and Design of a Unique Security Bollard Installment Using LS-DYNA for a K12 Vehicle Impact’, 13th International LSDYNA Users Conference, 2014. [5] S K Tay et al: ‘Crash Impact Modelling of Security Bollard’, 12th International LS-DYNA Users Conference, 2012. [6] B Hu et al: ‘Numerical Investigation of K4-rating shallow footing fixed antiram bollard system subjected to vehicle impact’, International Journal of Impact Engineering 63 (2014) 72-87. [7] NCAC. National Crash Analysis Centre http://www.ncac.gwu.edu/about.html [8] Ang Choon Keat, Professional Engineer (Civil), Singapore; Zoey Lim; Kong Jing Yan, ‘Test and Numerical Simulation of Fixed Bollard and Removable Bollard Subjected to Vehicle Impact’, 14th International LS-DYNA Users Conference, 2016, USA, June 2016.

Figure 6: Comparison of actual testing of vehicle impact and simulation model

Figure 7: Comparison of simulation results and actual test results

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[9] PAS68:2013. Impact test specifications for vehicle security barrier systems.

CONCRETE TECHNOLOGY

Advances in the use of concrete for supertall buildings by James Aldred, Technical Director, AECOM and Adjunct Assoc Prof, School of Civil & Environmental Engineering, University of New South Wales (UNSW Australia) If asked 20 years ago about the future tallest buildings in the world, most would have said that they would have a steel frame and be located in the United States. However, the 452 m Petronas Towers in Kuala Lumpur, which were named the world’s tallest in 1998, had a concrete core. In 2010, the Burj Khalifa opened in Dubai at a height of 828 m was a full reinforced concrete structure up to 600 m. The Kingdom Tower currently under construction in Jeddah with a designed height of over 1000 m will be the world’s next tallest building. It will be constructed with concrete. Concrete has become a crucial part in the construction of supertall buildings. One component has been that concrete is the preferred construction material in the Middle East and Asia where these structures have been built. However, even in the United States, supertall buildings such as Freedom Tower are being built with concrete. High quality concrete provides signiﬁcant beneﬁts to developers, consultants and contractors in building supertall buildings. Its high strength and modullus allows super tall buildings to have more slender vertical elements. Single-stage pumping to over 600 m has been demonstrated, which together with high early strengths allows rapid cycle times so that the construction rates of up to 2 to 3 levels per week can be achieved. This article discusses the technical advances of using concrete in supertall buildings as well as giving practical advice on some of the challenges. INTRODUCTION Until the 1990s, supertall buildings were almost always constructed in structural steel. Figure 1 shows the progression of the world’s tallest buildings from 1900. However, concrete has become an important part of the viability of super tall buildings, both structurally and economically. The stiffness provided by high modullus concrete helps limit movement. Increasingly higher compressive strength enables reductions in the cross section of vertical elements which do not require separate fireproofing. Pumpability and high early strength of high performance concrete coupled with prefabrication of reinforcing cages and advances in slip form/climb form technology mean that large complex reinforced concrete structures can be constructed at rates of 2 to 3 levels per week. Accordingly, properly designed reinforced concrete is becoming more competitive with structural steel in terms of the

Figure 1: A century of the tallest buildings [1]

speed of construction - the traditional advantage of steel. The durability of high quality concrete helps assure that the required service life will be achieved. Such concrete can be more sensitive than conventional concrete during the plastic and early hardening phase.This article discusses the author’s experience, to

THE SINGAPORE ENGINEER December 2016

help reduce the difficulties that may be encountered with using concrete in supertall construction, in order to optimise its considerable benefits to all stakeholders. HIGH STRENGTH Higher compressive strength has been a vital factor for the increased use of concrete in supertall towers. The ad-

CONCRETE TECHNOLOGY dition of silica fume and continued advances in high range water reducers have enabled the reliable production of field concrete with a characteristic strength of 100 MPa or more. By effectively doubling the average compressive strength, the cross-section of columns and other vertical elements can be almost halved, greatly increasing usable space. The reduced dead weight reduces the size and cost of foundations. Higher compressive strength concrete requires greater quality control. Variability in concrete production and testing can be assessed by either coefficient of variation or standard deviation. For concrete greater than 35 MPa, ACI 214R-11[2] suggests that a coefficient of variation of less than 7% indicates excellent quality control in the field concrete.The ACI suggestion would equate to a standard deviation of less than 7 MPa for a 100 MPa. However, Day et al [3] point out that a standard deviation of 3 MPa was measured for 200 consecutive results for concrete with an average 56-day strength of 99 MPa used on Petronas Towers. For the Burj Khalifa, a standard deviation of about 4.5 MPa was measured for 200 consecutive results for concrete with an average 28-day strength of 97 MPa (C80). The within test variability was 2.1 MPa which may explain some of the variability. Interestingly similar overall standard deviation and within test variation was measured for C50, C60 and C80 concrete grades. These examples suggest that standard deviation is a better indicator of quality than coefficient of variation for all strengths of concrete [3]. Basing quality assessment of high strength concrete on coefficient of variation using ACI 214R guidelines may give a false impression of ‘ excellence’. The author has been involved in assessing the fresh and hardened properties of high strength concrete for other supertall buildings. In one project, the design characteristic strength was 90 MPa. The average

compressive strength result was 105 MPa with an overall standard deviation of 11.2 MPa or 10.7% CoV. While this would be classified as ‘good’ control according to ACI 214R-11 [2], the variability had a detrimental effect on the fresh properties of the concrete, particularly, pumpability. In addition, when there is a high variability in production, the concrete has to be designed to an even higher potential strength. This can cause even more problems with rheology, particularly in regions where the design strength may be the same or higher than has been previously produced. The concrete producer can find himself in the invidious situation of increasing the target strength of the concrete but making the concrete more sticky and difficult to pump on site.The supplier is spending more money on the concrete and the contractor is getting more unhappy. The cost of producing concrete with a potential strength up to 20 MPa more than necessary is small compared to the cost of replacing hundreds of metres of piping caused by blockage. EARLY STRENGTH DEVELOPMENT Silica fume, high range water reducers and workability retaining admixtures increase early strength development which enables timely jumping of climbforms. For the Burj Khalifa, the strength requirement was 10 MPa at 12 hours. This required balancing the retardation and pumpability requirements with early strength.The pumping process tends to heat up the concrete and along with the larger section dimensions, will substantially increase in-situ maturity compared with standard specimens. The principal climatic challenge in Dubai was the punishing heat in summer and the loss of workability. However, the cooler winters where the night temperature can drop as low as 10° C did mean that the cube strengths sometimes failed to achieve 10 MPa at 12 hours but the in-situ strength was satisfactory.

This highlights the value of assessing the in-situ strength to prevent unnecessarily changing the mixture proportions to solve a problem that does not exist. Maturity gauges have been a useful advance to practically monitor in-situ strength development. Workability-retaining admixtures, when used in addition to high range water reducers, allow concrete to maintain its workability and other fresh characteristics throughout the transporting, placing, consolidating and finishing operations without adversely affecting the time of setting, early strength development and hardened properties (Daczko 2010). This type of admixture enables fresh properties of concrete to be achieved without the use of excessive dosage of a high range water reducer which may impact setting time. Higher early concrete strength together with prefabricating reinforcing cages and effective construction management can result in complex supertall concrete buildings advancing at 2 to 3 levels per week. Thus reinforced concrete is becoming more competitive with structural steel, even in terms of speed of construction. PUMPABILITY The benefits of using reinforced concrete in supertall buildings depends on pumpability. The speed of construction would plummet if large quantities of concrete had to be placed using cranes. Not only would the casting rate be limited to the size of skips and number of cranes, the cranes would be unavailable, during concrete placement, to perform all of the other functions necessary for construction. Another advantage of pumping concrete is that crane operations have to stop when the wind exceeds a predetermined speed. This is a particular problem in supertall buildings, due to the increase in wind speed with height and may result in plenty of downtime for the crane. Pumping concrete through central pipelines, as shown in Figure 2, is not affected by wind speed.

December 2016 THE SINGAPORE ENGINEER

CONCRETE TECHNOLOGY

Figure 2: Network of pipes at the ground level of Burj Khalifa allowing simultaneous concrete pumping to three locations.

The original plan was to conduct two-stage pumping on the Burj Khalifa. It is important to consider that any of the problems that can occur with pumping, can occur with the second pump in a two-stage system, potentially leaving many cubic metres of concrete stuck at the level of the second pump. After adjustments to the concrete mix and a pumping trial, the team was confident that single-stage pumping to the top of the reinforced core was feasible. One of the challenges in designing pumpable concrete is the increased use of crushed materials for both coarse and fine aggregate. The tendency is to use a high proportion of fine aggregate, particularly in concretes with a designed slump flow in excess of 500 mm. The use of a fine sand (<600 μm), limestone powder or cementitious materials increases the finer fraction component. A good fly ash, because of its spherical shape, is particularly useful in addition to the silica fume typically used in this type of concrete. In the case of the Burj Khalifa, the fine aggregate percentage for the mixes was approximately 50% and fly ash was used at a replacement level of 13% -20% together with silica fume at 5%-10% [5].

Figure 3: Horizontal pumping trial layout

If at all possible, a horizontal pumping trial is a useful exercise which allows the key parameters to be assessed without worrying about delaying construction in the event of causing blockage. The only parameter which is not replicated is the pressure head which can be added to the estimated maximum pump height based on the calculated friction factor. For the Burj Khalifa, pumping trials were conducted using a Putzmeister BSA 14000 HP-D stationary pump with a maximum hydraulic pressure of 310 bars. Six hundred metres of high pressure ZX 125 delivery pipes were laid out horizontally with transducers, to measure concrete pressure after pumping through 250 m, 450 m and 600 m (Figure 3). Fresh and hardened concrete properties were measured on the concrete before and after pumping. This procedure not only indicated that single stage pumping would be possible but also highlighted practical problems, which reduced possible blockage during construction. An alternative procedure to horizontal trials is the use of in-situ pressure transducers at the hopper, at the end of the horizontal section of the pipeline and at various elevations, to

THE SINGAPORE ENGINEER December 2016

establish the in-situ friction factor. The limitation of this procedure is that blockage of the pipeline cannot be allowed. However the fact that the pressure head is not initially high will generally mean that blockage should not occur. Measurement of the concrete’s rheological properties using a rheometer at the site can be a useful guide on the potential pumpability of the delivered concrete before pumping. There has been significant research in this area recently and the understanding of the influence of rheological properties on pumping has improved dramatically [7]. Appropriate positioning of pumps and planning of concrete truck flow on and off the site will help ensure smooth operation of pumping. There were three pumps on the ground floor at the Burj Khalifa, as shown in Figure 4, enabling concreting at three separate locations. Equipment and tools necessary to clear the pipeline in the event of blockage should be kept in a locked area near the point of discharge, to enable immediate action if required. An initial workshop with the concrete supplier, pump operators, contractor’s supervisors and consultant’s representatives, should be conducted, with an interpreter if necessary, so that all parties know the procedure and their roles.

CONCRETE TECHNOLOGY Direct pumping is another important development that can be useful in larger projects or where site access is limited or complicated. In direct pumping, the concrete batching plant discharges into a surge hopper and directly into the pump, eliminating the requirement for transit mixers. For the appropriate project, direct pumping can provide high quality concrete to a placing boom at the construction front with greatly reduce capital costs and traffic congestion. Another issue is the pipe diameter to be used. On the Burj Khalifa, a 150 mm diameter pipe was used with a reducer to connect to the placing boom. Using a larger diameter has the advantages of enabling larger maximum aggregate size and reducing the pumping pressure. However, the larger diameter pipes are more expensive and considerably heavier, and they require a greater quantity of concrete to fill and a reducer to connect to a placing boom. On balance, a smaller diameter pipe with a smaller maximum aggregate size would probably be a better option for most projects. In November 2007, using a Putzmeister 14000 SHP-D pump, a world record of 601 m vertical pumping was achieved as shown in Figure 4. Indeed the pumping operation was considered so successful that the contractor decided to pump relatively small quantities of concrete for metal deck composite slabs above the reinforced concrete structure to eliminate crane usage for concrete placement. This was in spite of approximately 11 m3 of concrete required to fill the pipeline. With suitable mix design and the advent of even more powerful pumps, it will be possible to conduct single-stage pumping to even greater heights than 600 m, provided the necessary care and precautions are taken. The Kingdom Tower project is currently under construction in Jeddah with a projected height in excess of 1000 m.The construction method-

Figure 4: Pump arrangement at the ground level

ology anticipates the use of two-stage pumping and a new concrete pumping height record is expected to be established. PLACING AND FINISHING Concrete for supertall construction is often designed with high workability and would be considered self-consolidating concrete (SCC) in many parts of the world. Care needs to be taken to ensure satisfactory rheology after pumping. On the Burj Khalifa, we found that the plastic viscosity tended to reduce and the dynamic yield stress to increase after pumping, which was the first reported observation of this phenomenon on a supertall project. This effect appears to be due to shear thinning of the self-consolidating concrete during pumping and can lead to segregation, if not considered. High workability concrete should be allowed to flow from the point of discharge and stop moving before any vibration is applied. In the case of vertical elements, small portable tremie pipes can be placed at the approximate flow distance apart, to reduce the time to position the placing boom or pump outlet. Such modifications to construction practices can be very helpful in supertall structures where the contractor should aim to keep

the concrete pumping at a constant rate, to avoid possible blockage that can occur due to articulation of the placing boom containing static concrete, particularly when the weather is hot. Any blockage in a placing boom should be avoided as it is difficult to clear and expensive to replace. The installation of a reducer near the pump can be a good precaution, so that concrete with a high segregation potential blocks at that location rather than elsewhere in the pipeline. This will not necessarily prevent blockage caused by a wet slurry or viscosity reduction during pumping, but it is a good precaution against variability in the delivered concrete. Concrete for supertall buildings typically contains 5% to 10% silica fume with a high cementitious content and has a tendency to rapidly form a â&#x20AC;&#x2DC;skinâ&#x20AC;&#x2122; under drying conditions. This skin formation can limit the melding of cast layers [8] and can be reduced by retaining moisture in the concrete surface by the use of evaporation retarders and other methods to reduce evaporation. This concrete also has virtually no bleed and can be quite cohesive. Therefore finishing works require workmen to develop

December 2016 THE SINGAPORE ENGINEER

CONCRETE TECHNOLOGY a feel for material. Trial applications should be conducted early, to enable the finishers to become familiar with concrete properties and to confirm an acceptable finish. Evaporation retarders facilitate finishing by retaining moisture in the upper layer, helping to eliminate sprinkling of water on the concrete during finishing which reduces surface quality. EARLY PROTECTION AND CURING Concrete incorporating silica fume and very low w/c ratios, such as the high strength concretes used in super tall buildings, have essentially no bleed. Therefore any surface drying will result in plastic cracking. An evaporation retarder is a very practical and inexpensive method to reduce plastic shrinkage cracking. Wind breaks and sun shades are helpful. Effective fogging is the best method as it can actually keep a high humidity layer at the concrete surface. Wind breaks may be necessary to confine the body of air above the concrete. For flatwork, concreting and finishing in the heat of the day should be avoided, with pours planned so that curing can commence before 10 am at the latest. A general guideline should be to have evaporation retarder and spray equipment available for every pour, if the rate of evaporation is more than 0.25 kg/m²/hr or 0.50 kg/m²/hr [9]. If plastic cracks do develop, the cracks concerned should be vibrated if the concrete has not reached initial set. Trowelling will only cover the plastic cracks. This may influence structural performance and provide pathways for chlorides to the reinforcement. The optimum form of curing for such concrete is ponding with water. This provides water to replace that used in hydration, improving concrete properties and helping to reduce early autogenous shrinkage. The latent heat of evaporation helps release the heat of hydration which can markedly reduce peak temperature, especially in concrete containing

fly ash, slag and natural pozzolans. The use of polythene over wet Hessian will help retain water in contact with the concrete surface but does not allow evaporative heat loss from the surface and ponding is best for thicker elements. For formed surfaces, the use of a controlled permeability form liner is a very good technique for improving the density and appearance of the concrete surface. The water that collects in the liner is also sucked into the hydrating concrete, providing excellent early curing for surfaces which are traditionally the most difficult to effectively cure. CONCLUSIONS Advances in concrete technology have provided significant benefits to developers, consultants and contractors in building supertall buildings. High strength and modullus mean that super tall buildings can have more slender vertical elements. Single stage pumping to over 600 m has been demonstrated, which, together with high early strengths, allows rapid cycle times, so that the construction rates of up to 2 to 3 levels per week can be achieved. Appropriate care and attention to mix design, placing, protection and curing can minimise possible problems with blockage, segregation, autogenous shrinkage and cracking. ACKNOWLEDGEMENTS Much of the data reported in this article is based on information from several supertall projects. The author would especially like to thank the staff of Emaar, developers of the outstanding Burj Khalifa project, as well as the technical staff from Samsung JV, Unimix and Putzmeister. REFERENCES

[1] A Century of Skyscrapers. http:// insights.globalspec.com/ar ticle/548/acentury-of-skyscrapers. [2] ACI 214R-02 ‘Evaluation of Strength Test Results of Concrete’, American Concrete Institute, Farmington Hills. [3] Day K W, Aldred J M, Hudson B

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(2014): ‘Concrete Mix Design, Quality Control and Specification’, 4th Edition, Taylor and Francis, London. [4] Daczko J (2010): ‘Innovative New Admixture for Flexible Slump Flow Retention in SCC Mixtures’, Proceedings from the 6th International Symposium on SelfCompacting Concrete and the 4th North American Conference on the Design and Use of Self-Consolidating Concrete. [5] Aldred J M (2007): ‘Pumping concrete on the Burj Dubai’, Terence C Holland, Symposium on Advances in Concrete Technology - 9th CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete, Warsaw Poland, Ed: George C Hoff, pp 497-514. [6] Aldred J M (2008): ‘Concrete pumping to 601 metres in a single lift’, Beton 2008, Istanbul, Turkey, pp 456-462. [7] Wallevik O H, Feys D, Wallevik J E, Khayat K H (2015): ‘Avoiding inaccurate interpretations of rheological measurements for cement-based materials’, Cement and Concrete Research, Vol 78, pp 100-109. [8] Roussel N and Cussigh F (2008): ‘Distinct-layer casting of SCC: The mechanical consequences of thixotropy’, Cement and Concrete Research, Vol 38, pp 624–632. [9] Hover K C (2006): ‘Evaporation of Water from Concrete Surfaces’, ACI Materials Journal, Vol 103, No 5, Sept/Oct 2006, pp 384-389. (This article is based on a paper ‘Advances in the use of concrete for supertall buildings’, authored by James Aldred, Technical Director, AECOM and Adjunct Assoc Prof, School of Civil & Environmental Engineering, University of New South Wales (UNSW Australia), and presented during a Special Session on ‘Forty Years of Innovation - Concrete and the Tall Building’ at the 40th Conference on ‘OUR WORLD IN CONCRETE & STRUCTURES’. Organised by CI-Premier Pte Ltd, the conference, was held from 27 to 28 August 2015, in Singapore).

CIVIL & STRUCTURAL ENGINEERING

October 2016 THE SINGAPORE ENGINEER

PROJECT APPLICATION

Repair work on the Parks Viaduct in Milan Advanced products and techniques were used in the refurbishment and protection of the concrete structure.

A view of the Parks Viaduct (Viadotto dei Parchi), after completion of the works.The viaduct, along the Milan East ring-road, is 3 km long and is made up of two 3-lane raised carriageways supported by 245 independent spans.

Built between 1969 and 1973, the Milan East ring-road on the A51 Motorway connects the A1 Milan-Naples motorway directly to the A4 TurinVenice motorway. Together with the A50 (Milan West ring-road), the A52 (Milan North ring-road) and the A58 (outer Milan East ring-road), it forms the largest system of ring-roads around any city in Italy, with a total length of 106 km. On average, more than 70,000 vehicles use this part of the motorway, every day. The Milan East ring-road is currently undergoing important upgrading work to increase the capacity of its links to the highways network in the area to the east of Milan, which is currently also being expanded through a series of important works along the Brescia / Bergamo / Milan (BreBeMi) motorway and the outer Milan East ring-road (TEEM).

The repair work became necessary because, over the years, the concrete on the underside of the viaduct had deteriorated and water was seeping through.

THE SINGAPORE ENGINEER December 2016

PROJECT APPLICATION The Parks Viaduct (Viadotto dei Parchi), along the Milan East ringroad, is 3 km long and is made up of two 3-lane raised carriageways supported by 245 independent spans. The viaduct is fed by the sliproads for Lambrate, Rubattino and Forlanini. Apart from updating and perfecting the prototype of the concrete slab viaduct in Viale Monteceneri (1959-1963), in Milan downtown, which, after 10 years, became the basic design for site-cast, pile-supported viaducts, this viaduct, which was built in 1973, is also the first example of the use of mobile, self-regulating formworks. In 2015, Mapei took part in the work, by supplying products to repair and protect seven joints on the underside of the Parks Viaduct, near the Rubattino slip-road. The work had become necessary because, over the years, the concrete had deteriorated and water was seeping through. The repair was carried out according to schedule, using â&#x20AC;&#x2DC;tried and testedâ&#x20AC;&#x2122; product systems that complied with all the requirements for this building site.

Before the works were carried out, the surfaces were prepared by removing the deteriorated cconcrete, through hydro-blasting.

Preparation of the concrete surfaces The first step was to remove the 3 cm to 5 cm thick layer of deteriorated concrete, by hydro-blasting an area about 2 m to the right and to the left of the joints, to create a compact, rough surface. After the hydro-scarifying operations, the surfaces were cleaned with high pressure water jets, to remove all traces of loose material. In so doing, apart from cleaning the concrete substrates, the steel reinforcement was also cleaned and prepared, for the application of the repair mortar. Three electrical connections were also made on the original steel reinforcement, on each side of the joint, by welding threaded galvanized rods directly to the rebar. Applying MAPEGROUT EASY FLOW by spray, to rebuild the joints.

December 2016 THE SINGAPORE ENGINEER

PROJECT APPLICATION Repairing the concrete surfaces After saturating all the surfaces with water, the joints were rebuilt and remodelled, by spray-applying MAPEGROUT EASY FLOW, a onecomponent, sulphate-resistant, fibrereinforced, shrinkage-compensated thixotropic cementitious mortar, which is particularly suitable for pumping over long distances and under constant high heads. A rendering machine was used for the sprayapplication. In order to ensure correct development of its expansive properties in the open air, MAPEGROUT EASY FLOW was admixed with MAPECURE SRA which made up 0.25% by weight of the mix. MAPECURE SRA is a special curing agent that allows repair mortars from the MAPEGROUT line to expand in the open air during the first few days of curing, thereby reducing the formation of micro-cracks and guaranteeing a very low rate of hydraulic shrinkage. Protecting joints against corrosion Once this part of the work was completed, MAPESHIELD E45 self-adhesive, pure zinc plates were installed, over a distance of around 1.5 m along each edge of the joints, to provide galvanic

cathodic protection against the corrosion of the steel reinforcement rods. The MAPESHIELD line is an active protection system based on the use of pure zinc anodes, which may be used for both renovation work and on new constructions, to prevent corrosion. In order to ensure high safety as well as perfect fixing and contact between the adjacent plates, additional plastic plugs were anchored on the MAPESHIELD E45 plates. Protecting the repaired areas and skim-coating the plates Once the plates had been fastened in place, the next step was to spray over the surface with MAPELASTIC GUARD, a protective, cementitious

waterproofing mortar, using a rendering machine with a skimming lance that had a nozzle. MAPELASTIC GUARD maintains its flexibility under all environmental conditions and is totally impermeable to water at pressures up to 1.5 atmospheres, as well as to the penetration of de-icing salts, sulphates, chlorides and carbon dioxide. Applying MAPELASTIC GUARD, therefore, is recommended when one needs to protect areas of concrete exposed to aggressive substances or even out surfaces protected with MAPESHIELD E45. To increase its capacity to level off and even out surfaces, MAPENET 150 alkali-resistant glass fibre mesh

Applying MAPESHIELD E45 self-adhesive, pure zinc plates.

MAPEGROUT EASY FLOW MAPEGROUT EASY FLOW is a one-component, pre-blended, packed thixotropic cement-based mortar composed of sulphateresistant hydraulic binders; synthetic polyacrylonitrile fibres; organic corrosion inhibitors; special water-retaining, expansive admixtures; and selected aggregates. It is applied using a spray rendering machine, to repair deteriorated concrete structures. The product is especially suitable when ease of pumping is required even over long distances and under constant high heads.

Additional plastic plugs were used to make the connections safer and to make sure each MAPESHIELD E45 plate was fastened securely.

THE SINGAPORE ENGINEER December 2016

PROJECT APPLICATION was embedded between the first and the second layers of MAPELASTIC GUARD. The surfaces were then treated with ELASTOCOLOR PAINT, a decorative, elastomeric, crack-bridging, permanently flexible, protective paint with high resistance to aggressive atmospheric agents and chemicals.

PROJECT DATA Project Parks Viaduct (Viadotto dei Parchi), along the Milan East ring-road on the A51 motorway, Italy

Year of Construction 1973

Original Designer Silvano Zorzi

INTERVENTION BY MAPEI Period of the Intervention 2015-2016

Clients

Applying MAPELASTIC GUARD.

Milano Serravalle Milano Tangenziali SpA

Works Direction Guido Ferro Marco Belli

Contractor Nuove Iniziative Srl

Contribution by Mapei Supply of products for repairing and protecting concrete

Mapei Products used MAPEGROUT EASY FLOW MAPECURE SRA MAPESHIELD E45 MAPELASTIC GUARD MAPENET 150 ELASTOCOLOR PAINT Website for further information www.mapei.com

This editorial feature is based on an article from RealtÃ MAPEI INTERNATIONAL Issue 59. All images by Mapei. The repaired surfaces were painted with ELASTOCOLOR PAINT protective coating.

December 2016 THE SINGAPORE ENGINEER

PRECISION ENGINEERING

Map for transforming Precision Engineering industry released At the launch of the iSmart Factory project, on 12 October 2016, by Meiban, a local Precision Engineering (PE) company, Mr S Iswaran, Minister for Trade & Industry (Industry), unveiled the Precision Engineering Industry Transformation Map (ITM). Led by the Singapore Economic Development Board (EDB), the ITM is the first industry-specific roadmap to be rolled out for the manufacturing sectors.The PE ITM has identified new growth areas that will take Singapore into the future era of manufacturing and create 3,000 PMET jobs, by 2020. Through the strategies outlined in the PE ITM, the industry’s Value Added is envisaged to grow from S$8.8 billion in 2014 to S$14 billion, by 2020. NEW GROWTH AREAS The Precision Engineering industry employed 94,000 workers and contributed S$8.8 billion in VA in 2014, which is nearly 15% of Singapore’s manufacturing VA. A key strategy of the ITM aims to shift the industry mix of PE towards higher value-added activities that would form the foundation for the next era of manufacturing. This will be done by growing complementary sectors such as robotics, additive manufacturing, sensors, advanced materials, and lasers & optics. Under the Research, Innovation and Enterprise (RIE) 2020 plan, Singapore has set aside S$3.2 billion for R&D in Advanced Manufacturing and Engineering. In Budget 2016, the S$450 million National Robotics Programme (NRP) led by the EDB and the Agency for Science, Technology and Research (A*STAR), was launched to develop an innovative robotics industry and to drive local lead demand and adoption of robotics. Similarly, the National Additive Manufacturing Innovation Clus44

ter (NAMIC) housed at the Nanyang Technological University has a dual mandate - to support R&D in additive manufacturing and adoption of the technology by SMEs. INNOVATION AS A KEY DRIVER The government will invest in new infrastructure that will help to build up new technical capabilities in local companies. The PE ITM will implement two key initiatives to encourage innovation. Model digital factories Digital manufacturing platforms will be set up in A*STAR’s Singapore Institute of Manufacturing Technology (SIMTech) and Advanced Remanufacturing & Technology Centre (ARTC) to develop digital technologies and solutions for MNCs and SMEs. The first phases are expected to be ready by 2017. These ‘model factories’ will showcase interoperability solutions and allow companies to test-bed and codevelop digital solutions. In this learning environment, companies can train and upgrade their workforce in digital manufacturing processes. Digital Champions EDB will groom PE companies ready to embark on transformative projects to digitalise their factory operations as ‘digital champions’. Homegrown Precision Engineering company Meiban is the first of such companies to embrace this vision and grant support. NEW JOBS AND SKILLS UPGRADING The move towards digital manufacturing in the PE industry would see the creation of 3,000 PMET jobs by 2020, in areas related to digital manufacturing, such as robot coordinators and industrial data scientists. Together with broad-based upgrading of jobs

THE SINGAPORE ENGINEER December 2016

for digital manufacturing, the PE workforce profile will shift significantly, with PMETs expected to account for more than half of the industry workforce by 2020, rising from 48% to 58%. Under the new Skills Framework for Precision Engineering launched by SkillsFuture Singapore (SSG), employers and workers will be equipped with insights on career pathways for 13 occupations, job roles, and training programmes. As part of the Adapt & Grow initiative under Workforce Singapore (WSG), Professional Conversion Programmes (PCPs) are being developed to support reskilling of mid-careerists keen to embark on new careers. WSG has also launched a series of advanced manufacturing masterclasses covering topics such as additive manufacturing and advanced robotics. Since February 2016, more than 300 PMETs have attended the masterclasses. COLLABORATION AND CONSULTATION To implement these new initiatives, EDB will work hand-in-hand with the industry, associations, unions and other government agencies. The ITM includes a plan to strengthen the membership of the Singapore Precision Engineering and Technology Association (SPETA) which will manage a pool of industry veterans to help SMEs chart their own growth paths. The scope of the Precision Engineering Sectorial Tripartite Committee will be expanded to provide inputs on the progress of ITM objectives. Comprising representatives from government agencies, unions and industries, this committee will be a key channel for engaging companies, industry associations, schools and the workforce, in the implementation of the ITM.

IES UPDATE

Spreading Christmas cheer with IES Community Services Committee Christmas came early for 30 students and Goodwill, Rehabilitation and Occupational Workshop (GROW) trainees from the Cerebral Palsy Alliance Singapore (CPAS), as they marvelled at festive lights first-hand in a vintage car ride down Orchard Road on 15 November 2016. In its second year, the CPAS-organised initiative aims to spread the joy and cheer of the Christmas season to its beneficiaries, who suffer from various disabilities and motor-function impairments as a result of cerebral palsy. The IES Community Services Committee (CSC) supported this meaningful initiative by hand-delivering specially-packed goodie bags for the CPAS students and accompanying them on the car rides. The event kicked off with a Christmas buffet sponsored by the Singapore Island Country Club (SICC) followed by an elaborate instrumental and choral performance put up by CPAS students from the Music and Dance co-curricular activity. A “Santa Claus”, together with his bagpipe-toting “elves” from the The Boys’ Brigade, 18th Singapore Company then trooped in and led volunteers to distribute various presents to the CPAS beneficiaries. A passing shower over SICC earlier that afternoon did little to dampen everyone’s spirits. Doing their part to support the CPAS initiative were Er. Edwin Khew, Er. Dr Lee Bee Wah, Er. Ong Ser Huan, Mr Mervyn Sirisena as well as CSC members Mr Au Yeong Hoh Wai, Er. Totong Kaya, Er. Richard Fong, Er. Yien Siew Sin and Eur. Ing. Kenneth Cheong. The party then adjourned to the nearby carpark, where the vintage cars awaited. These were driven by members of The Malaysia Singapore Vintage Car Register; the commitment of 30 vehicles this year doubling

Students getting ready to perform their Christmas carols.

All smiles for the camera as IES CSC gets ready to meet the kids!

Santa made an early stopover in Singapore for these special children. Photo: CPAS Facebook

that of 2015. With the evening cooled by the shower, the convoy then set off for Orchard Road with all the old-school charm one would expect from a fleet of beautifully-maintained workhorses. Seeing the smiles on everyone’s faces is definitely quite the uplifting experience! TSE

The vintage cars ready to roll out! Photo: CPAS Facebook

December 2016 THE SINGAPORE ENGINEER

IES UPDATE

In Case You Missed It: Some past events organised by IES Infrastructure and Integration Clusters Advanced Underground Pipe and Cable Locator When: 3 August 2016

dinner, sponsored by C. Tech Nova Pte Ltd , before adjourning to the auditorium to hear more about how fibreglass grid reinforced pavements integrate product elements, installation considerations, and performance outcomes.

well as the design approach for temporary works involved. Other topics covered included the supervision of the bored tunnelling constructions and common pitfalls encountered in the design and construction of such projects.

Updates on Design for Safety Regulations When: 5 October 2016

Sponsored by CE-Test Measurement Pte Ltd, the seminar was held to enlighten members about the techniques used to locate underground pipes and cables. The accuracy and reliability of information was an important point that was driven home many times during the 2-hour seminar, the reason being that the knowledge of their presence would enable engineers to work around them during building projects, therefore minimising disruption to essential utilities and services. Adaptive Design of Fiberglass Grid Reinforced Pavement When: 30 September 2016

The evening talk was held at IES Auditorium with around 100 people in attendance. Participants mingled over 46

This eventing talk, held at the IES Auditorium, focused on the Workplace Safety and Health (Design for Safety) Regulations 2015, which have come into effect since 1 August 2016. The WSH Council also released the latest WSH guidelines on Design for Safety during this period. The talk was therefore a timely opportunity to update practitioners and reconcile the intent of DfS implementation with the latest guidelines. Design and Construction Challenges in Deep Excavation and Tunnelling When: 18 October 2016 The full day seminar was held successfully at Furama Riverfront hotel with over 200 participants. It provided a refresher course to engineers and site supervision personnel on the various aspects and challenges of deep excavation and tunnelling projects, as

THE SINGAPORE ENGINEER December 2016

Climate Change and Nuclear Energy When: 28 October 2016 Held at the IES seminar rooms, Er. Edwin Khew and Prof Lui addressed climate change commitments made by Singapore at COP 21 to reduce carbon emission through the use of a range of renewable energy technologies such as solar, biomass, biogas, wind and ocean currents. A specific focus was also drawn towards the consideration of nuclear technology as a potential source of renewable energy in Singapore.

IES UPDATE

IES-SIAE collaborate to support aerospace engineering development in Singapore The two institutions sign an MoU to join hands in enhancing professional development for aerospace engineers and in nurturing young engineering talents

Mr Lim Yeow Khee, SIAE President (left) and Er. Edwin Khew Teck Fook, IES President (right) exchanging handshakes after signing the MoU.

On 25 November 2016, IES and the Singapore Institute of Aerospace Engineers (SIAE) signed a Memorandum of Understanding (MoU) to strengthen collaboration in aerospace engineering, focusing on professional development for engineers and promoting the profession as a career to students. Held as part of the 2016 graduation ceremony of the Air Transport Training College (ATTC), SIAE’s professional development centre, the MoU was signed at ATTC by Er. Edwin Khew Teck Fook, IES President and Mr Lim Yeow Khee, SIAE President. Under this MoU, IES and SIAE will exchange knowledge, expertise and networks to springboard a suite of activities such as conferences, seminars and workshops in aerospace engineering. The Singapore Airshow Aerospace Technology and MRO Conference, to be held in 2018, is one of the activities already in the pipeline. The institutions will also combine their expert resources to develop

and deliver training programmes and specialist courses for engineers and technicians, in partnership with ATTC. The MoU will also see both parties cooperate on developing and organising competitions and educational programmes for students, with partners such as Science Centre Singapore. IES will also work with SIAE to drive adoption of the IES Chartered Engineer Programme amongst aerospace engineers. The only professional accreditation programme in Singapore, it serves as an essential external validation of the experience, expertise and practising competence of qualified aerospace engineers, differentiating their professional standing and raising engineering standards in Singapore. “As our fast-growing aerospace industry aspires to make Singapore one of the top aerospace hubs in the world, it is crucial that we take action now to ensure that both the current and next generation of engineers and

technicians are ready to take on the challenges of the future. “As the national society of engineers in Singapore, IES looks forward to working with SIAE to complement Singapore’s physical infrastructure expansion for the aerospace industry by attracting more engineers into the sector, developing technicians into master craftsmen and engaging the interest of the young,” said Er. Khew. Adding on, Mr Lim noted that a strong aviation culture could only be achieved through proper education, training and development infrastructure, which would in turn attract talents to the profession. “This joint effort with IES to organise activities to encourage young Singaporeans to become engineers is timely, in view of the projected shortage of engineers to support critical industries in the coming years. It will also enhance SIAE’s mission to build a strong aviation culture for the Next Generation Aviation Professionals to grow on”, he said. TSE

December 2016 THE SINGAPORE ENGINEER

IES UPDATE

IES Fellow bequeaths S$1m to set up scholarship for project management As the Chinese saying goes, each generation reaps what the previous has sown ( qian ren zai shu, hou ren cheng liang). The efforts and contributions of our forebears have made the world a better place today. Keeping up with the eternal cycle of paying it forward, IES Fellow Mr Wong Yui Cheong has offered to bequeath SGD 1 million to the InEr. Chong (left) and Mr Wong (right) after signing the statement of formalisation for the bequest.The signing was witnessed by IES stitution to set up a Honorary Secretary Dr Boh Jaw Woei and CEO Ms Angie Ng, in the presence of some 50 members. scholarship fund for postgraduate research and study of construction project Management) programme, he has served in the highmanagement. est decision-making bodies of organisations such as the Documents formalising the bequest were signed be- Professional Engineers Board, where he was a council tween him and IES Immediate Past President Er. Chong member. Mr Wong was also IES Vice President from 1980 Kee Sen in a simple ceremony that was held on 1 Decem- to 1983. IES would like to thank Mr Wong for his significant conber 2016 at IES. The IES-Y C Wong Project Management Scholarship, as tribution towards the advancement of the profession. We also encourage all members to do likewise, be it it is known, will be managed by Mr Wong’s son Lester, as financially, or through your knowledge and expertise, leavwell as three representatives from IES. It will be open to graduates from all institutes of higher ing behind a legacy for those who would follow in your learning, especially NTU, where Mr Wong taught at from footsteps. TSE 1999 to 2011 after retiring from the industry. Further details on selection criteria will be released when they beADVERTISERS’ INDEX come available. Mr Wong, who is 85 this year, has had an illustrious caBENTLEY SYSTEMS –––––––––––––––––––––––––––––––– PAGE 15 INTERNATIONAL LIMITED reer spanning more than 40 years across various roles in the domain of civil and structural engineering, such as conIMI HYDRONIC ENGINEERING –––––––––––– PAGE 33 tractor, consulting civil and structural engineer, senior pubMULTININE CORPORATION PTE LTD –––––– PAGE 19 lic servant, construction project manager and real-estate SAMSUNG AIR CONDITIONERS ––––––––––– PAGE 21 developer. SUPER GALVANISING ––––––––––––––––––––––––– PAGE 17 He later moved on to construction project manMAPEI FAR EAST PTE LTD –––––––––––––––––– PAGE 39 agement, founding his own consulting firm, Y C Wong MITSUBISHI ELECTRIC –––––––– OUTSIDE BACK COVER Consultants. ASIA PTE LTD Even in retirement, Mr Wong has continually given WORLD ENGINEERS ––––––––––– INSIDE FRONT COVER back to the engineering community. Apart from lecturing SUMMIT 2017 in NTU’s Master of Science (International Construction

THE SINGAPORE ENGINEER December 2016