Our teams provide provide engineering, project management and multidisciplinary services across a variety of sectors, including marine and coastal, geoscience, buildings, transportation, energy, environment, water, flooding, waste management, and conservation.
Employer of Choice: In Ireland, we are a platinum Deloitte Best Managed Company and, in the UK, a Top 10 Ground Engineering consultant.(2)
Frameworks: We sit on several frameworks (18+) that deliver critical infrastructure, including Irish Water, The National Trust, and the Office of Public Works (OPW).
We have been present in the Middle East since 2009 with offices in KSA, UAE and Bahrain. Since then, we have completed over 1000 projects for leading public and private clients such as Qiddiya, Cruise Saudi, SWCC, Saudi Aramco, Diriyah Gate Development Authority, Amaala, Neom, Red Sea.
Technical Excellence: With a reputation for technical excellence, our highly skilled engineers take a complex problem and use critical thinking to navigate a path past any obstacles.
Multidisciplinary: Our multidisciplinary teams comprise over 70 different skillsets, with the expertise necessary to tackle the most challenging assignments, presented by each project. We collaborate across disciplines to provide solutions at the frontline of industry best practice.
Through our connected network of 12,000 professionals in 23 countries, we provide high quality, timely and cost-effective engineering, consulting and project management, saving clients considerable amounts of money and time by delivering valuedriven solutions.
Established in 1966, Ayesa is a leading global provider of engineering and technology consulting services. Ayesa is ranked #44 in the Top 225 International engineering design firms of the world. (1)
* In 2022, ByrneLooby in the UK, Ireland and the Middle East became part of Ayesa, a global leader in delivering major projects in transportation, critical infrastructure, water, energy, environment and waste management.
Geoscience
> Urban geotechnics
> Infrastructure geotechnics
> Engineering geology
> Underground space
> Site investigation
> Land quality & regeneration
> Surface water & groundwater risk assessments
Water
> Water supply
> Wastewater
> Drainage networks
> Tunnelling & conveyance
> Plant optimisation & resilience
> Resource management/Smart Water
Energy
> Renewable energy
> Energy generation
> Energy efficiency
> Transmission and distribution
Conservation
> Places of worship
> Residential heritage
> Commercial heritage
> Estates & country homes
> Scheduled monuments
> Heritage surveys and asset protection
Environment
> Sustainability
> Environmental impact assessment, planning and permitting
> Modelling, monitoring & compliance
> Ecology and biodiversity
> Climate resilience
> Hazard mapping, risk assessment and due diligence
Marine & Coastal
> Ports & harbours
> Coastal engineering
> Coastal modelling
> Marinas & waterfronts
> Planning & licensing
> Terminals & facilities
Flooding
> Flood risk assessment (FRA) and management plans
> Flood risk schemes (FRS)
> Catchment area planning & hazard mapping
> Flood resilience planning
> Flood Relief Schemes/Defence
Buildings
> Residential
> Office & commercial
> Public
> Leisure
> Education
> Health
> Temporary works
Waste Management
> Waste facility permitting & licensing
> Waste facility design
> Construction support
Transportation
> Highways and bridges
> Rail and metro
> Logistics parks
> Road safety audits
> Development infrastructure
> Tunnelling and ground engineering
> Temporary works
Consulting services led by engineering, technology, digital transformation, sustainability and innovation, and supported by decades of experience.
WORLD
#44 International Engineering Design Firms (1)
SPAIN (1)
#3 Top International Engineering Design Firms Top 5 IT Consulting Firms
LATIN AMERICA
#6 Top 10 By Region (1)
UK
#9 Top 50 Geotechnical Consultants (2)
(1) ENR Rating: Top 225 International Engineering Design Firms 2023 (according to revenue)
(2) (Geplus.co.uk) Ground Engineering Magazine’s top UK Geotechnical Consultants ranked according to UK revenue
(3) Includes the recent acquisition in August 2022 of Ibermatica, creating combined turnover of 649m euros in 2022
We promise to keep delivering outstanding work, as an end-to-end partner.
3
PEOPLE CENTRIC
Best in class engineering, innovative solutions with global best practice and a focus on sustainability
We build long-lasting relationships with clients to add value and return on investment. Ayesa sits on a number of national infrastructure frameworks in Ireland and the UK
A workplace where innovation is encouraged where skills, sustainability, diversity and continuous development is a priority.
When working on a project, how construction interacts with its surrounding ecosystems and ground conditions is often the source of the most significant risks and uncertainties. Ayesa has become an acknowledged leader within this sector, analysing difficult ground conditions on both greenfield and brownfield land, solving complex geotechnical challenges by providing robust and practical solutions for various development projects, whatever the size or scale. Our geotechnical expertise can be applied effectively to projects, whether water, marine, energy, civil, buildings, rail and conservation.
Our international experts in geotechnical engineering identify and mitigate ground-related risks through rigorous investigation, analysis and design. We have completed large scale schemes across all construction sectors, providing designs including foundations, retaining walls, tunnels, shafts, earthworks and slopes. We form integrated geotechnical and structural design teams capable of providing fully coordinated solutions, maximising the reliability and efficiency of our projects. We assist with determining the optimal construction sequencing and provide practical and value-driven geotechnical solutions, such as ground movement assessments, contaminated land remediation and soil-structure interaction.
We are equipped to manage the geotechnical inputs on projects from the initial investigation phase to on-site monitoring during construction. Our experienced engineers and geologists are industry leaders in specifying and managing geotechnical investigations and interpretative reporting. Numerical modelling has developed rapidly over the past decade, and often the quality of geotechnical investigative data is the limiting aspect for developing intricate models and assessments. We undertake complex 3D modelling for projects to investigate any impact on surrounding assets due to ground and structural movements. The use of ground engineering will help improve the design of structures and can reduce asset-lifecycle costs by using the latest methods and technologies. Our staff will ensure the necessary data is captured during the investigation phase to offer clear benefits to the design and modelling phase – whether this is a city centre basement development or a large linear infrastructure project.
Urban Geotechnics
Infrastructure Geotechnics
Engineering Geology
Underground Space
Site Investigation
Land Quality & Regeneration
Surface Water & Groundwater Risk Assessments
For over 20 years, Ayesa has successfully worked on urban projects across various ground conditions by supplying geotechnical engineering and below-ground design services. Our team consists of geotechnical engineers, civil engineers and engineering geologists who deliver tailored solutions to meet individual urban project and client requirements. We have extensive experience in design and construction in various ground conditions throughout cities in Ireland, the UK and the Middle East.
Cities worldwide are struggling with a myriad of environmental and social problems with air, water and soil pollution and crowded, ageing infrastructure. Innovative solutions are essential to combat these problems by utilising underground solutions and maximising space.
Our geotechnical engineers contribute to exciting and challenging projects, many of which are major national and international schemes built within densely populated areas. In the buildings sector, we have provided foundation and basement designs for The Shard in London, the New Children’s Hospital in Dublin and the visitor centre at Titanic Belfast.
Often, we apply complex 3D modelling on projects to understand the impact on surrounding assets due to potential ground and structural movements. We provide detailed earthworks and sub-structure solutions for large urban infrastructure schemes such as the Crossrail line extension in London, the Doha Metro scheme in Qatar and the M50 widening in Dublin.
Our expertise covers all aspects of geotechnical and geological engineering, from planning, investigation and feasibility studies to design, construction surveillance and operations and maintenance.
One of London’s most iconic landmarks, The Shard is a striking silhouette in the skyline. As one of the tallest buildings in Europe, The Shard reflects the ambition and vision of the City. With its location in the heart of London, any works on The Shard risked a considerable impact on its neighbours; most notably the adjacent London Bridge station, a Victorian structure and integral transport hub for the city.
Ayesa was appointed as the detailed designer for the substructure, including a top down construction sequence for the triple level basement. As the project is adjacent to London Bridge station, a central hub on London’s rail network, the rail authority (Network Rail) required detailed analysis of the effect of the basement excavation on the Victorian station structure. Ayesa undertook a detailed Ground Movement Assessment and successfully satisfied Network Rail and their technical advisors, gaining approval for our design.
The solution designed by Ayesa included a secant piled wall to allow for the deep excavation, piled foundations, and plunge columns. The original foundation concept involved the piles being base grouted. Following a successful preliminary pile test to record settlements and strains, Ayesa argued that base grouting was not necessary and provided a value-based alternative. The final solution comprised 60m deep, 1.8m diameter, bored piles founded in the underlying Thanet Sand.
Location: London, UK
Capital Value: £350m
Project Name: The Shard Country: UK
Client: Balfour Beatty Ground Engineering
Project Kells (later rebranded as 60 Dawson) is a large retail and office development in Dublin City Centre at Dawson and Nassau Street. The proposed works includes the construction of a new, four to six-story high mixed-use building. As part of the redevelopment, it is proposed to complete a bulk excavation for a two level below ground deep basement.
Two sides of the proposed basement are parallel to the LUAS Cross City Line, at the junction between Nassau Street and Dawson Street. The basement is approximately 3.4m to 7.1m from the nearest LUAS running rail. In the temporary case, excavations of 10.15m to 10.75m bgl are required.
Ayesa worked closely with the clients (PJ Edwards) from the tender stage providing consultancy services covering design methodology, monitoring, and detailed design of the secant pile wall and temporary support to the wall during construction.
To facilitate installation of drainage and services, excavation depths up to 10m and 11m bgl have been accounted for in the temporary case. The designs had to meet tight movement criteria and we proposed a real time instrumentation system, to ensure that the works had no adverse impact on adjacent sensitive structures and the live LUAS light rail line.
Ayesa also completed the design of permanent works foundation piles. The installation of foundation piles was required to accommodate large compression loads where the top of bedrock was well below the basement formation level.
Ayesa also completed the design of the capping beam for the temporary works to distribute the support from the temporary propping and tie back anchors along the secant pile wall. Extensive studies were also done on the possible construction methods for constructing the pile caps and piers in the marine environment. Both bridges were designed using post-tensioned concrete box girders of uniform depth – each carrying 2 lanes of traffic, with inclined piers supporting the spans over water and vertical piers for spans over mud flats.
Location: Dubin, Ireland
Capital Value: €58m
Project Name: 60 Dawson Street
Country: Ireland
Client: PJ Edwards & Co. Ltd.
The ESB head office building on Fitzwilliam Street Lower is a stunning new commercial building in the heart of Dublin city centre. The 45,000m² development comprises two commercial office buildings with the protected historic Georgian houses on Mount Street that were restored and refurbished into modern, high-quality residential properties, maintaining their protected status. The 45,000 sqm space will feature sustainable technologies to reduce carbon emissions and energy costs, resulting in a near-zero energy building. With an excellent BREEAM rating, the project is one of Dublin’s most sustainable and efficient office developments.
This was a complex construction project in an extremely busy city centre environment, so stakeholder management was crucial. Ayesa served as a specialist designer for P.J. Edwards, focusing on the detailed design of the perimeter secant pile wall. The secant wall consisted of approximately 400 linear meters and required the installation of over 650 piles. To ensure stability, the wall was reinforced using pre-stressed glass fiber-reinforced polymer (GFRP) anchors, strategically placed under streetscapes. The use of GFRP anchors was chosen in collaboration with (Dublin County Council) DCC to prevent any future obstruction of service installation beneath the adjacent streets.
Additionally, Ayesa was responsible for the detailed design of 450 foundation-bearing piles and 150 anti-flotation anchors for the substructure.
Throughout the project, Ayesa also acted as a temporary works designer for PJ Hegarty, providing assistance across various on-site elements.
Location: Dublin
Capital Value: €58m
Project Name: ESB Head Quarters
Country: Ireland
Client: PJ Edwards & Co. Ltd.
The Project won the award for Large Commercial Project of the year at the ICIA Irish Construction Industry Awards 2022.
Dublin’s Charlemont Square project marks the second phase of the Charlemont Street revitalization initiative, aiming to rejuvenate the urban landscape of Dublin 2. This ambitious €210 million mixed-use development encompassed the transformation of approximately 13,000m2 of constricted space in the city center. The project was completed between January 2018 to December 2022 and has created a vibrant central hub for the local community.
To pave the way for progress, four outdated residential blocks were cleared, making room for six new multi-story blocks that now house 96 top-tier apartments. The ambitious undertaking engaged a total of 203 subcontractors and became the most extensive excavation project within Dublin’s canal area.
Ayesa provided a detailed design package for the construction of a contiguous pile retaining wall and a secant pile retaining wall to support the excavation of a single and double level basement for the proposed Charlemont Street development in Dublin. The retaining walls were designed to be installed using continuous flight auger (CFA) piles, with various sections of the walls being temporarily supported by propping during the short-term condition. The pile design requirements were determined in accordance with relevant codes and guidelines, and the walls were assumed to be supported by the basement and ground floor slabs in the long-term condition.
The design was completed at the request of the client P.J. Edwards & Co. Ltd.
Location: Dublin
Capital Value: £210m
Project Name: Charlemount Square
Country: Ireland
Client: PJ Edwards
Cadenza, Earlsfort Terrace is a 13,000 m² flagship office development built for leading pension and investment company Irish Life. The Cadenza project consists of a modern office development over 8 floors with bespoke facades and sustainability deliverables of BER A3, NZEB compliance, LEED Platinum V3, WELL Gold V1, WiredScore and enhanced Smart building metering & monitoring.The building comprises six office floors above a lower ground floor and a singlelevel basement. Its construction includes an RC concrete frame with post-tensioned slabs, while the facade boasts a unique structural glass wall with an external tapered stone veil.
Ayesa completed the secant pile wall design and temporary works support measures as part of the enabling works contract for the redevelopment of Davitt House, Earlsfort Terrace, Dublin 2 into its new incarnation as Cadenza Earlsfort Terrace.
The contractor submitted a comprehensive report outlining a detailed design and certification proposal for the permanent works secant pile. The project involved several key stakeholders, including Walls Construction Ltd as the main contractor, Waterman Moylan Consulting Engineers (WM) as the engineering team, PJ Edwards & Co. Ltd (PJE) as the piling contractor appointed by the main contractor, and Ayesa acting as the pile designer on behalf of PJE.
In order to facilitate the excavation of a two-level below-ground basement, a secant pile wall was installed to provide structural support. Additionally, temporary support measures were implemented in specific areas to minimize lateral movement of the wall during the excavation stage.
Location: Dublin
Capital Value: Undisclosed
Project Name: Davitt House (now Cadenza Earlsfort Terrace
Country: Ireland
Client: PJ Edwards & Co. Ltd. and Walls Construction
Previously Davitt House
Ayesa has a proven track record providing costeffective and innovative geotechnical solutions for earthworks, earth retaining systems, structure foundations and asset management for multiple infrastructure sectors, including roads, rail, metro and marine environments.
With growing populations in urban areas and an increased need for connectivity and sustainability - there is a growing need to understand the geotechnical risks presented by major transportation infrastructure projects. Our expertise in this area means that we can successfully manage projects from design to construction. As a multidisciplinary consultancy, we aim to provide our clients with the information they need to understand and minimise ground risks, mitigate uncertainties and remediate by delivering value-added solutions based on engineering experience and technical knowledge.
Working across various sectors, locations, and project scales, our versatile team at Ayesa evaluate ground risks and advise mitigation solutions across all phases: scheme feasibility, planning, concept design, detailed design and project implementation. Our skills are uniquely honed to meet the demands of the Design and Build sector. Our understanding of construction processes, methods and focus on buildability have proven invaluable assets for our clients. Working on both local and international projects, we have provided geotechnical services across various challenging terrain: road scheme engineering on soft ground in Ireland, mountainous terrain in Kosovo and Albania and seismic conditions at the US$5bn New Aqaba Port. We have consulted on rail earthworks, and slope remediation works on the London Crossrail (UK) and worked on significant metro projects in Doha and Jeddah.
Our advice spans many vital areas essential for project success; site inspections, planning and managing geotechnical investigations, geological mapping, geotechnical monitoring and instrumentation, groundwater and hydrogeological assessments, geotechnical design and reporting, emergency geotechnical assessment and repair strategy, scheme asset management and heavy maintenance planning, temporary works design, independent checking services, expert witness and construction services.
The Royal Commission in Jubail (RCJ) plans to construct two new bridges: one from Jalmudah to Al-Batinah Island (Battinah)and the other from Dareen to a nearby unnamed island (Dareen). Batinah is a 4-lane bridge proposed to replace an existing causeway to allow increased access to Abu Ali Island. Darren is a 2-lane bridge designed to replace a smaller existing bridge to link the mainland to an island with oil production facilities. Both bridges have been designed with a 60m main span to clear a 40m navigational channel to allow safe navigation of vessels up to 15m in length.
Ayesa in association with FAEC was commissioned by the RCJ to undertake the detailed design of both bridges, the approach causeways, the marine works including lining the channel, protection for the piers and navigation aids. Detailed assessments included carrying out a detailed study for the form, shape and location of both bridges. The location and height of each bridge was determined considering the existing causeway and bridge remaining in operation until each was opened. Extensive geotechnical investigations were carried out to ensure the optimum piling solution was found for all piers in varying ground conditions. The long-term settlements of the approach embankments were also taken into consideration.
Extensive studies were also done on the possible construction methods for constructing the pile caps and piers in the marine environment. Both bridges were designed using post-tensioned concrete box girders of uniform depth – each carrying 2 lanes of traffic, with inclined piers supporting the spans over water and vertical piers for spans over mud flats.
Ayesa utilised our multidisciplinary team to supervise the ground investigation works, as well as providing a range of specialised expertise. The bridges were designed around a principle of ‘balanced aesthetics”, combining striking design that blends seamlessly with surroundings and delivers constructability and cost-efficiency.
Location: Jubail, KSA
Capital Value: Undisclosed
Project Name: Royal commission Bridges
Country: KSA
Client: Royal Commission of Jubail (RJC)
OUR ROLE
Ayesa was the civil and geotechnical designer for the contractor designed elements (CDE) for this £13m scheme of Class A trunk road in Enniskillen, Northern Ireland.
The 2km route runs through areas of deep very soft ground comprising peat and very soft lacustrine clays and key challenges included finding cost effective solutions to improve the competency of these soft ground locations to facilitate construction of the trunk road.
For the areas of soft ground, ‘excavate and replace’ techniques were used to improve the ground. Ayesa supervised construction of the soft ground replacement with engineered fill in a controlled, phased approach, in order to mitigate against potential instability of adjacent lands.
We were involved from the tender to construction stages, and also developed a value engineered soil nail solution as an alternative to the conceptual reinforced concrete retaining structure, saving the client both time and costs in the process.
Ayesa also provided the detailed design of a public and a private footbridge, and their associated approach ramps and bank seat abutments supported on reinforced earth embankments.
Location: Enniskillen, UK
Capital Value: £13m
Project Name: A32 Cherrymount Link
Country: UK
Client: P.T McWilliams/Mclaughlin & Harvey JV
The design and construction of a new 1.4 twin bore Silvertown tunnel under the river Thames in London Is being delivered by the Riverlinx CJV, a partnership of three civil engineering and construction companies: BAM Nuttall, Ferrovial Construction and SK ecoplant. The Riverlinx CJV have established a high-quality team of specialists to design the tunnel including Ayesa. Ayesa is the lead underground structural designer of the temporary and permanent works, including the cut and cover tunnels, TBM shafts and other structures. The Silvertown tunnel will link Silvertown to Greenwich and will reduce the chronic congestion of the 122year old Blackwall tunnel and regenerate this derelict area. The construction is following the Tunnel Code of Construction Practice (CoCP), which prioritizes minimizing construction-generated carbon emissions, by transporting all materials by river and using lowemission machinery.
OUR ROLE: Ayesa is the lead underground structural designer of the temporary and permanent works of the cut and cover tunnels, three massive complex TBM shafts, portal structures and open-cut structures, damage assessment and instrumentation and monitoring The tunnel excavation is using two tunnel excavation methods: TBM (tunnel) and Cut and Cover (tunnel access ramps).
VALUE ADD:
Innovation for better Programme and Cost outcomes: Ayesa’s notable contributions include input into the design of the “Peanut Shaft,” a pioneering temporary shaft that helped launch the largest TBM ever used in the UK as well as the “rotation shaft” which was used to turn the TBM for its second drive. This “Peanut shaft” received an award for innovation at the New Civil Engineering Tunnelling festival 2022. It replaced the original client concept and combines four 21.2m diameter shafts connected through T-shaped counterfort structures, maintaining a curve to fit road alignment without external ground treatment or anchors. Ayesa conducted feasibility assessments and explored global solutions to arrive at this final concept, which replaced the original rectangular box design. The successful launch of the tunnel boring machine in September 2022 marked a significant milestone. In March 2023, the first tunnel was completed, and to save costs and reduce construction time, Ferrovial made the decision to rotate the machine, dismantling and rebuilding the TBM would take 6 months. In response, Ayesa designed the oval-shaped chamber that accommodates the TBM’s 180˚ rotation in sections, while avoiding existing utilities. The chamber is 18m deep, 40m long, and 39m wide, with openings for the TBM tunnels to the north and access to the cut and cover tunnel section to the south. The team rotated the first 1,400t section the TBM 180° in the reception chamber using an innovative “nitrogen skate” system.
Stakeholder Collaboration: Although not contractually required, Ayesa’s close collaboration with COWI the lead designer, which included sharing expertise, optimising workflows and creating more efficient design interfaces, helped minimise pandemic delays.
Advanced Techniques: Ayesa employed 3D modeling and Plaxis 3D for simulating shaft construction, while 2D Plaxis was utilized
Location: London
Capital Value: £2b
Project Name: Silvertown
Country: UK
Client: Riverlinx Consortium
for the construction of Cut and Cover North. In addition, Ayesa designed the temporary support for the shafts and developed the dewatering plan for the construction of the rotation launch and retrieval shafts. Ayesa’s optimization efforts included the design of anchors and struts for the temporary support of Cut and Cover North. The work carried out by Ayesa showcases their commitment to innovation, collaboration, and delivering value to their clients in a complex, challenging, multi-stakeholder scheme.
Tunnel Length 1.4km
Access Ramps 0.6km
Economic Cost Saving £10m p.a
Location: London
Capital Value: £2b
Project Name: Silvertown
Country: UK
Client: Riverlinx Consortium
The project has wider ambitions than a new tunnel - it aims to regenerate the 62-acre Silvertown site with a restoration of the iconic 1930’s Millennium Mills, the construction of a bridge connecting Silvertown Quays with the Custom House Crossrail station, and the creation of the Roundhouse East, a music and education event space. This comprehensive development will breathe new life into Silvertown, transforming it into a vibrant hub for the community of London. The Silvertown tunnel will address traffic pollution and congestion while enhancing connectivity across London.
Ayesa is the lead underground structural designer and part of the project team who are assisting the Riverlinx CJV consortium (Ferrovial, BAM Nuttall Ltd PPP PGGM, SK Engineering & Construction Co. Ltd) to deliver a 1.4km twin-bore road tunnel under the river Thames. Just as Marc Brunel invented the tunnelling shield in 1818, this project is responsible for launching many “firsts”, including the awardwinning “peanut” launch chamber, a “rotation chamber”, and a “retrieval” chamber to help drive the largest tunnel boring machine (TBM) ever used in the UK.
Challenges: Prioritising eco-friendly practices, the team uses low-emission machinery and river transport for construction materials. The 780,000 tonnes of spoils from the recently completed second tunnel were removed by barge. At the start of the project, remnants of demolished structures from heavy industries presented site challenges. In addition, the engineering team had to grapple with the complex task of maintaining a 4% vertical gradient while optimising ground coverage between the tunnel crowns and the Thames riverbed. During the early part of the project (early 2020), COVID-19 posed challenges, including dispersed teams, geographical locations and delays to the site. Ayesa recognised that shared interfaces between their team and the geotechnical designer COWI would hugely benefit from collaboration, even though contractually, they were not required to work together. In the face of successive COVID lockdowns, this collaboration yielded benefits such as optimised workflows, reduced review times and client costs. Ayesa and COWI adapted design programs to accommodate pandemic-related delays in ground investigations and leveraged their knowledge
“Silvertown Tunnel - transforming East London’s Infrastructure”
to optimise design interfaces. Through their strong working relationship, Ayesa provided valuable workflow efficiencies and innovation, resulting in Ayesa, COWI and the Riverlinx CJV being shortlisted as finalists in the GE Geotechnical Team of the Year 2022.
Ayesa Lead Underground Structures Design: Ayesa designs various tunnel project components, including temporary and permanent structures in cut and cover areas, TBM shafts, and portal structures. The firm also manages damage assessment and supervises instrumentation and monitoring efforts. The project utilises two excavation methods: TBM for the primary tunnel and Cut and Cover for the access ramps.
Design Details: Ayesa is designing crucial elements such as the Cut and Cover North and South, which serve as the access ramps for the Silvertown and Greenwich Districts. The company is also at the forefront of designing several control shafts, including the Rotation Shaft that links the Silvertown Tunnel to Cut and Cover South. The walls of the cut and cover sections are being built with secant piles. Ayesa’s engineers have employed advanced techniques such as 3D modelling and Plaxis 3D to simulate the construction of the shafts. For the construction of Cut and Cover North, they utilised 2D Plaxis. Ayesa also designed temporary support for the shafts and developed a comprehensive dewatering plan for the construction of the rotation launch and retrieval shafts.
Award-winning Launch Shaft (Peanut Shaft): Ayesa and the project team played a crucial role in designing the awardwinning Launch Shaft, otherwise known as the “Peanut Shaft”. This shaft has successfully launched the largest Tunnel Boring Machine (TBM) ever used in the UK. The innovative design, which won the NCE award for innovation in Shaft Design and construction, features four 21.2-meter diameter shafts connected through T-shaped counterfort structures. The design maintains a curve to align with the road without requiring external ground treatment or anchors. Ayesa + COWI conducted extensive feasibility assessments, exploring the original client concept design and innovative global applications before arriving at the final peanut-shaped solution. On September 7, 2022, the TBM was successfully assembled in the launch chamber of the Peanut shaft. With impressive dimensions of 82 meters in length, an 11.91-meter cutter face, and weighing a staggering 1,800 tonnes, Jill drove the tunnel at a remarkable pace of 10 meters per day. By February 2023, the first drive was completed.
Rotation Shaft: For the second tunnel, to enhance costefficiency and streamline operations, Ferrovial decided to rotate the TBM 180 degrees, as disassembling and reassembling a single TBM could take six months, which would be costly. In response, the Ayesa team devised an innovative “rotation chamber” design with an oval shape, measuring 18 meters in depth, 40 meters in length, and 39 meters in width. This chamber allowed the TBM to rotate 180 degrees in sections, avoiding interference with existing utilities. The chamber features two openings, facilitating TBM tunnels leading to the north and access to the cut-and-cover tunnel section towards the south. The rotation of a 1,800t machine was also made possible by moving it onto “nitrogen skates” which used a complex hydraulic jacking system.
Retrieval Chamber: Ayesa is also responsible for designing the final destination of this mega TBM called the “Retrieval Chamber,” and it is now being disassembled. The “launch”, “rotation”, and “retrieval” chambers have performed their
functions successfully, delivering the project safely and on time. The main tunnelling works at Silvertown are now completed. Works on the ‘cut and cover’ sections of the Silvertown tunnel, including portal entrances, are now being delivered. A temporary bridge has been installed on Millennium Way, allowing excavation of the ‘cut and cover’ section to continue beneath it.
The project remains on target to be completed in 2025.
Innovation: Ayesa is taking a central role in the Silvertown Tunnel project, providing inventive designs and team collaboration to meet challenges and deliver exceptional results. Notable among Ayesa’s contributions is the design of the “Peanut Shaft,” a ground-breaking temporary shaft that enabled the launch of the UK’s largest TBM, named “Jill.” This novel design won the Innovation in Shaft Design & Construction award and replaced the initial concept from the client. It features a unique concentric circle structure, removing the need for external ground treatment or anchors. Additional shafts, such as the Rotation Chamber and the Retrieval Chamber, are also used to manage the TBM’s journey.
Using Innovation for Improved Programme and Cost outcomes: The successful launch of The record-breaking TBM, Jill in September 2022 marked a significant milestone in the project. Ayesa’s oval-shaped rotation chamber, meticulously designed to accommodate the TBM’s 180˚ rotation in sections, demonstrated exceptional maneuverability and minimized construction time and costs. With a depth of 18m, a length of 40m, and a width of 39m, the chamber will eventually provide two openings for the TBM tunnels to the north and access to the cut and cover tunnel section to the south.
One Team: Ayesa’s contributions extended beyond innovative designs. Through close collaboration with COWI, their shared expertise and efficient workflow management resulted in optimized design interfaces and minimized delays caused by the COVID-19 pandemic.
Advanced Techniques: Utilizing advanced modeling techniques and specialized software, Ayesa simulated shaft construction and provided comprehensive designs for various structures, including the Cut and Cover sections and control shafts which have worked successfully to maneouvre one of the largest TBM’s in Britain’s history.
Engineering Geologists provide the bridge between the built and natural environment and our diverse team of geologists and civil engineers, allow us to take a holistic approach to design. Our engineers are constantly exploring innovative ways to optimise designs based on the conditions at the site, which means every design we provide is unique.
Ayesa engineers are experienced in assessing earthworks for signs of distress and designing remediation solutions to stabilise structures that could be at risk of failure from stresses such as climate change, subsidence, capacity limit and ageing or non-resilient materials. During site visits, we investigate infrastructural risks associated with earthworks and recommend long-term and short-term mitigation strategies. Our engineers undertake kinematic, limit equilibrium, and finite element analyses to accurately model earthworks and deliver optimal design solutions. Our engineers work across various sectors, including rail, highway, infrastructure, and private construction.
Our rope-access trained geologists can get up close to investigate tricky and remote areas that would otherwise be inaccessible. While there, they assess hazards, tactilely inspecting, taking structural rock measurements, and logging slopes to gain a complete understanding of risks presented by earthworks. Our studies and investigations can be conducted in numerous phases of public and project projects: planning (including assessing environmental impacts), civil/structural engineering design, value engineering, construction, forensic phases and post-construction. We can provide comprehensive assessments, including geological hazard assessments, for geotechnical, material properties, stability of landslides and slopes, erosion, flooding, dewatering, and seismic investigations.
Guildford Sands, Guildford, UKThe original Gobbins coastal path was opened in 1901 but fell into disrepair and was closed in 1951. This reconstruction project consisted of a series of 23 footbridges and cantilevered walkways forming a 1km-long pathway at the base of 60m-high cliffs spanning between rock outcrops and sea stacks along the Antrim Coast. The pathway follows the original route and the iconic bridges have been reconstructed to closely match the original Victorian structures with original steps and walkways retained.
Ayesa acted the geotechnical designer for the bridges, cantilever anchorage systems and cable stayed anchors for the main contractor, McLaughlin & Harvey Ltd. We also carried out rockfall assessments and site investigations and developed value engineered solutions along the coastal pathway route to mitigate against unstable sections of the cliff face. We developed a rockfall management plan to assist in managing operational rockfall risks, through a systematic process of geological inspections, continual monitoring and intermittent tactile assessments.
Location: Larne, UK
Capital Value: £4.5m
Project Name: The Gobbins Cliff Path Walkway
Country: UK
Client: McLaughlin & Harvey Ltd.
Following a period of very wet weather, in February 2020, a section of cutting slope along the RBS1 line between Rugby & Coventry failed, resulting in slumping of the shallow slope material and formation of a significant back scarp. In response a temporary speed restriction was put in place and emergency works undertaken to remove the slumped material and install additional temporary support along the toe. Ayesa were engaged by J Murphy & Sons (working on behalf of Network Rail) to assess the cutting and undertake the design of both temporary and permanent solutions. The permanent solution comprised a concrete RediRock™ wall and slope regrade. This arrangement was eventually extended over a length of approximately 200m of cutting slope to address other areas of concern.
Following an emergency callout and weekend inspection of the slope failure, Ayesa’s initial role was to design a temporary works arrangement to make safe the failed sections. Once the cutting slope was made safe, Ayesa then undertook the detailed design of the permanent solution. During the construction stage Ayesa provided regular site attendance and additional design activities as required to ensure successful delivery of the project.
After a review of the retaining wall options to support the cutting toe, the use of pre-cast concrete “Redi-Rock” blocks was selected due to its quick construction time and engineering performance. The construction of the slope regrade above the new toe wall was completed using a combination of “Menzi” slope climbing excavator and a long reach machine. This removed the need for plant to be in the cess and hence lengthy track possessions.
Location: Coventry, UK
Capital Value: £2m
Project Name: Brandon Cutting
Country: UK
Client: J Murphy & Sons Ltd
Location: Wadhurt, London UK
Capital Value: £3m
Project Name: Wadhurst Cutting
Country: UK
Client: BAM Ritchies/Network Rail
Ayesa has been supporting our client BAM Ritchies/ Nuttall on their journey to help Network Rail provide better, reliable journeys on key routes. The Wadhurst Cutting project is an excellent example of collaboration to produce outstanding results for the client. The value engineering work carried out by Ayesa, Ayesa significantly reduced both the cost and programme of the project and the close relationship between the project team (BAM Ritchies/Nuttall/Ayesa allowed for any construction issues to be mitigated) quickly and correctly. The steep cutting was dug more than 170 years ago and has suffered from several landslips in recent years, causing significant disruption to passengers on this key line of route between the coast and central London. This stabilisation work creates more reliable train services between the capital and Hastings and and secures a lifespan of at least 60 years.
Summary: Our combined project teams at Ayesa and BAM RItchies designed and delivered new strength and resilience to this 170-year old cutting, using a combination of active and passive rock bolting, netting and soil nails in an area with logistical challenges, protected species and a zero safety incidents.
Project Background: Wadhurst Cutting is located on the Tonbridge to Hastings rail line, running approximately 300 metres from the north and south tunnel portals. The cutting height ranges between 8 to 18 metres and the geology consists of weathered Wadhurst Clay, underlain by the Wadhurst Clay Formation and Ashdown Formation. Following failures of the over steepened cutting over a few years (2014, 2016, and 2019), Network Rail appointed BAM to install a Network Rail approved design to remediate the cutting.
The project was planned in two phases: the country end (Initial emergency works) and the London end. It involved a wide range of geotechnical stabilisation installations, which you would expect to see on failing earthwork infrastructure. There were a number of independent systems working alongside each other: an active soil nail system on the upper slopes of the cutting consisting of nails that varied in length (from 5 metres to 14 metres). This was meshed using Greenaxe integrated mesh and erosion matting on the active soil nails. There was also a passive rock bolt drape net system with rock bolts top and bottom, with the top row following the undulation of the rock crop from the tunnel portal until it dropped away to ground level. The third system was an active rock bolt system for the first 20 yards either side of the portal as it opens up. The soil nails head up the bulk of the installation with approximately 13,000 l/m installed and in excess of 1,000 l/m of rock bolts. The meshed area in total is approximately 15,000m2 when all systems are combined. Subsequent to vegetation removal an additional LiDAR survey was completed. The results of this survey guided further design refinements, which resulted in the shortening of the soil nails in two sections.
During analysis of the emergency work associated with the Network Rail design, it became clear that there was an opportunity to challenge the design and significant value engineering could be applied for the majority of the stabilisation project. BAM Ritchies approached Ayesa and requested a value engineering feasibility study to confirm if, and to what degree, value engineering was possible.
Through the analysis, our team confirmed savings were possible by increasing the reinforcement mesh strength which allowed for the soil nails spacing to be increased from a one 1 metre by 1.5 metre grid to a 1.5 metre by two 2 metre grid. The horizontal spacing of the rock bolts over the lower portion of the cutting was also increased from 2.2 metres to three 3 metres. These proposed alterations to the design offered a 46 per cent reduction in the liner meters of soil nails and rock bolts installed and reduced the programme by 20 weeks, reducing overall cost by around £1.5 million. Network Rail were impressed with the level of savings offered whilst maintaining compliance with specifications, standard details and Eurocodes. Due to time constraints the value engineered design was only
“The power of collaboration including supply chain partners, created one team focused on the project’s success.”
applied at the London End.
BAM Ritchies used the blockade at the country end in October 2021 to deliver the emergency works that secured the installation of lower rock bolts and soil nails, which had not been possible during earlier ALO working. It was a very busy half-term on the blockade. The project team provided an incident-free 7 days of digitally rehearsed, predictable, sustainable delivery, providing resilience to the earthwork’s infrastructure at the Kent and Sussex Railway. BAM Ritchies installed over 450 soil nails and rock bolts, with a total meterage in excess of 2,200 metres. Three drillings rigs, working over 2,700 hours, were fuelled by HVO instead of diesel, reducing the carbon footprint by 90 per cent.
Our approach is to combine the knowledge of everyone across the project team to continually challenge and deliver better outcomes despite the challenging strata, which combined Wadhurst clay sited over Ashdown rock formation. After some test drilling with the selfdrilling nails it became apparent the preferred system for production drilling and installation was not going to be straight forward as as the Wadhurst clay was becoming extremely hard. This problem was overcome by the application of hydraulic drill heads fitted to the traditional air masts and a hybrid system was installed that still used air flush to open hole but with the speed associated with a hydraulic terrapin face rig. Production, as a result exceeded expectations. This was an example of daily innovation delivering improving outcomes for Network Rail.
The project placed a strong emphasis on sustainability, evident through deliberate measures taken to avoid unnecessary complexity in the design. Additionally, careful consideration was given to erosion protection strategies for the slope. Originally, the plan specified the incorporation of a plastic-based erosion mat into the reinforcement mesh. However, after discussions with the erosion mat supplier, it was revealed that their products degrade within two years, leading to the release of microplastics into the environment. Once this potential environmental concern emerged, BAM Ritchies and Ayesa engineers collaborated with our team to explore alternative options. As a result, we successfully persuaded Network Rail to endorse a shift to woven coir matting, which posed no environmental risks.The site presented ecological challenges such as the presence of a badger sett inhabited by resident badgers. This required obtaining a license and permission to temporarily close the sett before commencing our work. Furthermore, the site was inhabited by Dormice, necessitating the creation of a “dead hedge mouse highway” to divert them away from the construction area. Additionally, we secured permission to plant Dormice-friendly vegetation once the project was completed. While at Wadhurst the project team worked in partnership with EAVE using GEN3 ear defenders, to provide a productive work environment using advanced hearing protection and noise analytics. The trials were carried out over 2 weeks, with Eave leaving site with some excellent data on noise exposure during site operations.
Reduced risk of landslips on the line – in the past decade alone, engineers have visited the Wadhurst tunnel on numerous occasions to secure the railway and install temporary fixes to weather-related movements. This stabilised the Wadhurst cutting with 5,400 soil nails and mesh, with 15,000m2 of vegetation removed to help protect the railway from landslips and other extreme weather.
The seven-day emergency blockade during October half-term meant engineers could strengthen the cutting, making it as secure as possible as quickly as possible.
• Less overall disruption to passengers and the benefits delivered sooner – the blockade condensed essential work into the shortest period so the overall disruption to passengers was significantly reduced.
• Better, more reliable journeys – this essential work will help reduce the number of delays in the long term and therefore improve passenger journeys.
• Cost and Programme Savings: The proposed BL alterations to the design offered a 46 per cent reduction in the liner meters of soil nails and rock bolts installed and reduced the programme by 20 weeks, reducing overall cost by around £1.5 million with less materials input.
• Reduced environmental risks: A switch recommended by our team to woven coir matting instead of a plastic-based erosion mat, presented less pollutant risks to the environment.
• Ecologically sympathetic outcomes: The planting of dormice-friendly plants, upon completion of works.
• Value Engineering better outcomes: The value engineering efforts undertaken resulted in substantial reductions in both the project’s cost and timeline. The strong collaboration between BAM Nuttall, BAM Ritchies, and Ayesa enabled swift resolution of any construction challenges. The contributions of BAM Ritchies have played a crucial role in assisting Network Rail in ensuring improved and dependable travel experiences along the critical London to Hastings route for a minimum of the next six decades.
Population growth, urban development and the requirement for environmental preservation have led to underground space becoming increasingly important in solving urban problems. Ayesa has been involved in a wide range of projects in the underground space sector, providing design services to clients throughout the project cycle from initial concept design through to detailed design and construction supervision to solve critical infrastructure needs. Our team of geotechnical engineers, structural engineers, engineering geologists and civil engineers deliver project and client requirements in areas such as tunnelling, deep shafts, temporary works, retaining walls in a variety of ground conditions throughout Ireland, the UK and the middle east.
Our team of engineers are regularly involved in challenging and complex projects working directly for developers, as well as supporting contractors with design and build services.
In Qatar, our role included the selection of the tunnel alignment and shaft locations and the design of permanent and temporary shafts for the Lusail Expressway. While, as part of the Elan Valley Aqueduct, we designed several TBM (tunnel boring machine) launch and work shafts including a 30m deep, 13.5m diameter permanent secant pile walldrop shaft.
As part of the New Children’s Hospital project, in Dublin, our appointment included the detailed design of close to 1km of permanent secant pile wall for the triple-level basement. Through close collaboration with our clients and technical expertise and experience in this area, we provide efficient and effective design solutions.
The new Crossrail line in London divides at Stepney Green, with one line continuing north and one line crossing the Thames to the south. A deep shaft and large mined cavern was required at this location as TBM reception and launch and to accommodate the converging tunnels. The shaft was constructed using deep diaphragm walling techniques. The tunnel cross-passages are some of the largest ever constructed using sprayed concrete lining, being 50m long, 17m wide and 15m high.
Ayesa was initially appointed by the specialist contractor SPIE UK to design and detail the diaphragm wall. This wall facilitated the enormous 35m deep excavation, with the wall panels being 1.2m thick and 50m deep. A particular challenge was the detailing of the reinforcement for the wall panels, ensuring these large cages could be safely lifted from horizontal to vertical for placement into the excavation. Each cage weighed 25 tonnes necessitating a robust temporary works design.
Subsequently, the main contractor DragadosSisk JV appointed Ayesa to design the temporary propping to facilitate excavation of the shaft. We worked collaboratively with Dragados-Sisk to devise the value engineered construction methodology and sequencing and internal support system in order to accelerate the construction program and improve buildability. Ayesa also provided guidance on the cross-passage excavation stability and the sprayed concrete lining solution.
Location: London, UK
Capital Value: Undisclosed
Project Name: Stepney Green, Crossrail
Country: UK
Client: SPIE UK
As part of the sewer network upgrade in the Kingdom of Bahrain, a 23m deep pumping station was constructed on the man-made reclaimed island of Diyar Al Muharraq. To enable the construction of this pump station a 23m diameter shaft was constructed using 900mm interlocking male and female secant piles.
Ayesa undertook a detailed design review and value engineering exercise for the deep shaft. This included an independent check on the process design and the structural design, a geotechnical assessment of the proposed solution along with the overall final configuration and suitability. Advice on the dewatering strategy in this aggressive marine environment was also provided, including consideration of pile overlap, drilling methodology and the degree of water cut-off that could be achieved.
Location: Diyar Al Muharraq
Capital Value: Undisclosed
Project Name: Diyar Al Muharraq - Pump Station
Country: Bahrain
Client: Undisclosed
Unforeseen ground conditions may represent the most significant hazards for a construction project. A site investigation can investigate and pinpoint these potential hazards and significantly reduce risks. Inadequate site investigation can result in delays to the programme and necessitate a remedial plan to rectify contaminated soils and groundwater and/or re-construct building systems. Ayesa geologists, engineers, environmental scientists and technicians deliver value-added, riskbased, site-specific solutions. Our comprehensive range of field services can identify the nature and extent and risk of substances found in soil, sediment, surface water, groundwater and building systems. Our services span the entire lifecycle, including site investigation and feasibility studies, risk assessment, monitoring, remedy selection, remedial design, site reuse, and preparation of competitive tenders to third-party specifications as well as construction management.
Our clients range from individuals to major contractors and developers to constructing energy from waste (EfW) facilities and peaking plant power stations. We have experience working in challenging environments such as soft Ground, peat bogs, slopes with specialist rigs or scaffold platforms, overwater investigations in harbours, rivers and lakes, landfills, crane lifts and buildings basements and other below-ground structures.
We employ a combination of in-house and thirdparty resources to undertake site investigations using techniques to maximise the quality of the data obtained. These techniques include cable percussion boring, rotary open-hole, cored drilling, Geobor and resonance equipment with appropriate flushing mediums to maximise recovery, dynamic (windowless) sampling and probing, static cone penetration testing (piezocone, magcone, seismic cone, gamma cone) and mechanically and handexcavated trial pits.
We prepare the Ground Investigation Report (GIR), the Geotechnical Design Report (GDR), and specific geo-environmental interpretation and recommendations. We present exploratory hole and other test data following the current local quality standards (British, EU or the Middle East) and are Eurocode 7 compliant. The ground investigation data can be presented electronically in the latest AGS format for inclusion in BIM.
Qiddiya is set to become the Kingdom’s capital of Entertainment, Sports and the Arts to meet and satisfy the recreational, social and cultural needs of current and future generations. Located 45km west of Riyadh, Qiddiya will comprise of a Resort Core, Motion Zone, City Centre, Eco Zone Golf Community, Aerodrome and Airfield Future Development and Green Buffer development zones.
Overlooking the Resort Core from its perch 200m above on the edge of the Tuwaiq escarpment, will be a City Centre mixed-use village dedicated to sports & the arts. Qiddiya’s City Centre development area covers approximately 530,000m2, allotted across 33 plots.
Ayesa was appointed by the Qiddiya Investment Company, to provide geotechnical support for the proposed development in Qiddiya. Our role included identification and detailed requirements for test and investigations by plot, preparation of the required tender documents, review of technical & commercial submissions and provide any additional support. As the lead geotechnical Consultant, our scope included the provision of specifications, drawings, BOQs for pricing and monitoring works during construction, as well as GIS drawings and data.
Ayesa utilised BIM modelling by integrating Holebase SI and Civil 3D along with Autodesk Infraworks. This aided with faster revisions of the site investigation layout to reflect the masterplan layout changes.
Location: Qiddiya, Riyadh
Capital Value: SAR 30bn
Project Name: Qiddiya Geotechnical Investigation
Country: KSA
Client: Qiddiya Investment Company (QIC)
Brockaghboy Wind Farm is located in County L/ Derry and consists of 19 Vesta 3MW V90 turbines and 8.6km of access tracks. Ayesa in Belfast acted as the civil, structural and geotechnical consultant on the project. We provided designs for crane hardstands and access tracks, including optimisation and value engineering of the client’s tender package along with SuDS & drainage design for this difficult, hilly site.
We also provided solutions for culvert crossings and bridge structures and public road upgrade works for the turbine delivery route. Our structural team provided designs for the 19 wind turbine gravity bases. Ayesa undertook site inspections, sign offs and approvals of turbine base formation level, finished hardstand and access track surface. This project was promoted by the major Italian energy provider ERG.
Location: County Derry, Northern Ireland, UK
Capital Value: £65m
Project Name: Brockaghboy Wind Farm
Country: UK
Client: Adman Civil Projects Ltd.
Our team was appointed to provide enviromental assessment, permitting support for the project as well as landfill remediation and design. The Heathrow Expansion Programme is a £14bn project to construct a third runway and new taxiways linking it to the rest of the airport complex, a new terminal building and satellite, additional stand areas, new airport gateways, carparks and other associated infrastructure. It will involve re-routing the M25, diversion of rivers and substantial earthworks to achieve.
Our primary role was to provide advice on the remediation of three existing permitted landfill sites located along the line of the proposed new runway and to design and support the permit applications for four new landfills. The new runway is to be constructed on top of three pre-existing landfills posing complex remediation and foundational design issues. The existing leachate and landfill gas control systems needed to be replaced and a new capping system installed.
The four new landflls are being designed to EU/UK standards and need to take account of their close proximity to a working airfield with associated access restrictions. Our Waste team were subcontracted to Jacobs who were appointed as lead earthworks consultant for the project. Our role in this project was multi-disciplinary with our consultants providing a full range of services; earthworks design, site investigation support, hydrogeological risk assessments, stability risk assessments, air quality assessment, design of landfill gas, leachate and odour control systems, environmental monitoring, regulatory compliance and advice on landfill tax.
Location: Heathrow
Capital Value: £15bn
Project Name: Heathrow Airport Expansion
Country: UK
Client: Jacobs Engineering
PROJECT
A ‘first class’ approach to expanding one of the busiest airports in the world
Location: Newbridge, Kildare
Capital Value: €100m
Project Name: Lidl DC
Country: Ireland
Client: Lidl GMBH
Lidl Newbridge Distribution Centre (DC) is a new 58,000m2 distribution centre constructed on the outskirts of Newbridge, Co. Kildare. The new Distribution Centre will serve Lidl’s network of stores in the Leinster area and create 100 full-time jobs for the area.
Variable soft cohesive and loose granular materials were encountered within the initial 3m to 4m below ground level during the ground investigation. A ground improvement scheme was proposed at the site to reduce foundation costs over traditional piled/ bulk dig and replace solutions.
Ayesa’s role (2016-2019) on the project was to appraise the initial ground improvement solution, prepare the earthworks and ground improvement specification, review the contractor design and build proposals and tender returns, review the ground improvement works and review the compliance reports.
Following the tender process, a soil stabilisation solution of lime and cement stabilisation was selected as the most suitable solution.
Ayesa ensured that the construction works were carried out in accordance with the overall project and designer’s specifications to ensure the settlement criteria would be met. This involved numerous site visits and reviewing them in situ as well as laboratory testing.
Following the completion of the works, a detailed review of the compliance reports was conducted to ensure the works had been completed to the required specifications.
The innovation in this project lies in the ground improvement scheme proposed by Ayesa for the construction of Lidl’s Newbridge Distribution Centre. Instead of using traditional piled or bulk dig
and replace methods, a soil stabilisation solution of lime and cement stabilisation was implemented. This innovative approach offered several benefits:
Cost Reduction: The ground improvement scheme aimed to reduce foundation costs compared to conventional methods. By using lime and cement stabilisation, the need for extensive piling or bulk excavation and replacement was eliminated, resulting in cost savings for the project.
Time Efficiency: The alternative ground improvement solution helped expedite the construction process. Compared to traditional methods that require more time for piling or extensive excavation, the use of lime and cement stabilisation allowed for quicker preparation of the ground, enabling faster progress on the project.
Enhanced Stability: The stabilisation of variable soft cohesive and loose granular materials beneath the ground provided improved stability for the distribution centre. By treating the ground with lime and cement, the soil’s strength and load-bearing capacity were enhanced, ensuring a solid foundation for the facility.
Compliance Assurance: Ayesa played a crucial role to ensure construction works were carried out in compliance with the project’s specifications.
Through site visits, in-situ review, and laboratory testing, they ensured that the ground improvement works were carried out in accordance with the design requirements, meeting the settlement criteria.
Distribution Centre, Naas, Ireland - at 58,000m2, is one of the largest single buildings in Ireland.
The Lidl Regional Distribution Centre project in Mullingar is a 15,000m2 extension to Lidl’s existing centre in Lough Sheever Park, Mullingar. Opened in April 2023, Lidl’s new distribution centre is not only the largest on the island, totalling 62,000 sq.m, but it is also one of the most energy-efficient buildings in the country. Following an €80 million investment, the centre incorporates an impressive 1.2MWp solar array, making Lidl the country’s largest owner of rooftop solar arrays.
Ayesa managed the ground investigation including part-time supervision. The scheme involved ground improvement works and upfilling of up to 3m to connect the extension with the existing structure. The Ground conditions were varied across the site with an area of Peat located in the east of the site. Following the ground investigation, Ayesa prepared the Interpretative Report detailing encountered ground conditions, geotechnical risks and geotechnical recommendations. Ayesa then assisted the Engineers for the scheme in preparing the Performance Specification, reviewed the tenderers’ technical submittals and reviewed the appointed contractor’s detailed design. The final solution involved excavating to a suitable subgrade and backfilling and compacting using ground stabilisation techniques. Ayesa subsequently carried out construction supervision. During construction, we supervised and designed temporary haul roads to facilitate the ESB plant relocating overhead pylons.
Our work leveraged advanced techniques, datadriven insights, and tailored design solutions to enhance decision-making, mitigate risks, and optimize project outcomes: Our geotechnical team specified an extensive round of Peat Probes that confirmed peat depths to allow the clients to make more informed commercial decisions regarding the proposed development. Ayesa designed temporary haul roads and platforms to facilitate the relocation of overhead pylons for the ESB plant. As part of the ground investigation, Ayesa prepared a detailed schedule of laboratory testing to enable a detailed classification of the soils and inform the appointed contractor of likely mix designs for ground stabilisation proposals.
Location: Mullingar Ireland
Capital Value: €80m
Project Name: Lidl DC Mullingar
Country: Ireland
Client: Lidl GMBH
We offer a fully integrated geotechnical and environmental consultancy, providing a wide range of services from initial feasibility studies and investigations to the design, management, supervision and validation of remediation projects. With expertise in a range of disciplines, our geo-environmental staff work together to assess the natural and anthropogenic issues relating to site conditions within the context of a proposed or existing development.
With over 20 years in the contained land sector, Ayesa has extensive experience in providing practical solutions to our client’s brownfield site issues. Developers of brownfield sites across the UK face the challenges of an industrial legacy and our aim is to adopt a collaborative approach with clients to understand the feasibility, opportunities and constraints in relation to the regeneration of a brownfield site. Contaminated Land is a field with strict legislative standards and we assist with initial site appraisals to master planning to optimise land value and discharging planning conditions.
Our technical advice, risk assessment and appropriate mitigation can help you find a cost-effective and safe solution that meets statutory requirements. We assist developers to resolve the contamination issues that increase risks and add uncertainty to programme, costs and schedules. Our teams have delivered services at every stage of contaminated land management from initial due diligence and desk study through to investigation, risk assessment, remediation and postcompletion monitoring. Our team understands the regulatory frameworks surrounding contaminated land and land quality issues in different jurisdictions. We take a pro-active approach working with regulators to achieve solutions that satisfy legal requirements while minimising delays to development projects.
Our consultants are adept in the preparation and completion of Conceptual Site Models (CSMs), undertaking environmental risk assessments following the source, pathway, receptor model and developing remedial options. With an excellent working knowledge of the planning regime and contaminated land legislation, our team are able to provide guidance and support to clients through all aspects of development.
Our consultants have a wide range of experiences from small scale residential developments through to large-scale commercial and industrial projects. In partnership with experienced contractors, we deliver a fully coordinated ground investigation, remediation or earthworks programme to comply with regulatory requirements in both the planning and legislative frameworks. When you work with Ayesa, we combine our geo-environmental, geotechnical, environmental and structural engineering services to deliver an integrated costeffective approach with a lens on sustainability.
The Sorting Office is located in Dublin’s North Lotts and Grand Canal Dock Strategic Development Zone, a regenerated city quarter which is home to a number of international technology companies such as Facebook and Google.
The development - being undertaken by Marlet Property Group - includes the construction of 56 residential units, 12,000 sq ft of retail space and 202,000 sq ft of office space across 7 storeys plus a basement.
The Sorting Office development site was considerably contaminated due to former uses of the dock area. The design solution, detailed by the engineer, involved the installation of a 1m wide diaphragm cut off wall to attenuate the contamination on site in order to prevent migration off site, potentially negatively impacting the nearby River Liffey.
Ayesa value engineered a bespoke design solution to reduce the construction programme and costs of constructing the cut off wall, detailing a cementbentonite cut off wall which could be constructed using standard CFA piling techniques in a secant arrangement. Detailed testing and compliance inspections ensured the scheme was completed to the highest standards, with the required permeability and depths achieved to ensure the contamination is attenuated on site over the design life of the scheme.
Location: Dublin
Capital Value: €158m
Project Name: The Sorting Office, Cardiff Lane
Country: Ireland
Client: PJ Edwards and Co. Ltd.
Location: Snowdonia
Capital Value: £12m
Project Name: Adventure Parc Snowdonia
Country: UK
Client: D Morgan plc / Conwy Adventure Leisure Ltd
The centrepiece of the Adventure Parc is the Surf Snowdonia fresh water lagoon, in which artificial surf is generated. It is roughly the size of six football pitches, set in the Conwy Valley, North Wales and features a two-metre high barrelling wave that peels perfectly for more than 150 meters. The Adventure Parc also features a range of other facilities including glamping pods, a restaurant and various other indoor and outdoor leisure activities.
Conwy Adventure Leisure Ltd. (CAL) and their contractors, (D Morgan) built the Surf Snowdonia facility on a former Industrial site – an aluminium rolling and casting works which closed in 2007.
Before they set to work, it was a derelict, contaminated, brownfield wasteland with little prospect for development. Ayesa undertook extensive site investigations, undertook the contaminated land assessment and made recommendations for the clean-up and redevelopment of the site.
Surface water in streams and rivers is an essential resource, as is the groundwater stored below ground in geological strata called aquifers. Ayesa conducts complex groundwater and surface water risk assessments to guide the design and management of many public and private projects and fulfil compliance and regulatory obligations.
When undertaking water-based risk assessments, we combine inputs from multiple experts (hydrogeologists, hydrologists, water and geotechnical engineers) analysing the flow and quality of water and its implications across the entire ecosystem. Our expertise within this area is evidenced by our consulting services across significant wide-ranging schemes: our hydrological and surface water risk assessments guide the design of the flood relief schemes at Arklow and Bandon Ireland; the team’s groundwater monitoring (including baseline and post-remediation) of our land remediation solution at the Ineos Grangemouth Chemical Facility provided the regulatory approval and validation to help deliver the £50 million energy from waste facility.
We utilise groundwater flow models to inform water resource management, schemes and planning by simulating current conditions and predicting the effects of land-based activities. Our groundwater modelling specialists develop site-specific conceptual and detailed models such as the SWAT model for surface water catchments and the WAVE Modflow and MT3D for groundwater. We model the contaminant and its impacts on receptors. The resulting applications allow us to evaluate and predict contaminant migration, dewatering, potential human health impacts, and design mitigation solutions.
We complete detailed hydrogeological risk assessments for the planning and environmental permitting of new landfill sites. Our hydrogeological risk assessments ascertain the necessary pumping activities and permits needed to dewater quarry sites before commencing a new development. We complete geological and hydrogeological risk assessments to support planning applications for Energy from Waste facilities and for extractive mineral activities.
We help our clients meet the monitoring requirements set out in their environmental permits and discharge consents through monitoring programmes. Our specific water quality sampling services of groundwater and surface water combines chemical, biological and toxicological assessments to support compliance. Landfills are required by legislation to periodically review hydrogeological risks to ensure that original site risks and groundwater risk assessments are valid, and we report to the relevant authority on behalf of the client (required by UK regulators, the Environment Agency, the Scottish Environmental Protection Agency, National Resources Wales and the Northern Ireland Environment Agency.)
We also provide risk assessments for discharges to surface water from landfill leachate and surface drainage. Our knowledge of leachate composition also allows us to consider, outline, and design treatment options to minimise the impact of discharges on surface water and provide long-term sustainable management solutions.
We design passive treatment systems that provide long term solutions to low concentration but environmentally significant pollutants including the design of reed beds for the treatment of weak landfill leachate to complex wetland constructions that remove nitrogen from sensitive waters in chalk streams in Hampshire.
Location: Sohar
Capital Value: £20m
Project Name: Sohar IWHTF
Country: Oman
Client: Al Ahlia Environmental Services
Ayesa was appointed the lead design engineer for the Sohar Industrial Waste Handling and Treatment Facility (IWHTF), one of the world’s largest hazardous waste management facilities being developed by Oman Environmental Service Holding Company (Be’ah).
The facility includes three landfill sites, which will provide 18 million m3 of void space on the complex together with a 30-hectare development platform, which will accommodate a range of waste storage and treatment facilities.
The first cells of a Class I Hazardous Waste Landfill, Class II Non-Hazardous Waste Landfill and Inert Waste Landfill were was constructed as part of the Design and Build Contract. The Hazardous Landfill incorporated a double composite engineered containment lining system, a basal leachate collection system and an adjacent leachate evaporation pond. The Class II landfill was constructed with a single composite lining system and a separate evaporation pond.
Our primary role was to prepare the 30 year masterplan, provide detailed designs and construction support for three new landfill cells and to design the 400,000 m3 earthworks for a 30-hectare development platform.
Our brief on this Design & Build contract included tender support, site investigations, environmental monitoring, hydrogeological studies, earthworks design, geosynthetics design, surface water management design, site-based construction support (including CQA) and preparation of the operations, environmental monitoring and closure plans.
PROJECT FOCUS: engineering one of the largest hazardous waste facilities on the planet
