Geotechnical

Investing in SMARTer Ground Investigation

All rail enhancements, renewals and investment projects rely upon the ground to respond in a certain way when loads are applied by the chosen ground engineering solution

To ensure the expected performance of the ground there is a need to gather information and data of the ground that will be relied upon. This capture of information and data is undertaken through the completion of Ground Investigation (GI) projects. The SMARTer the ground investigation the better the results and the more risk is reduced in delivery of the project in the future.

BAM Ritchies has an extensive fleet of GI plant, capable of undertaking any investigation, whatever the constraints, requirements or topography. With over 55 years of drilling experience BAM Ritchies are enabled to work with consultants and contractors to identify targeted GI that fully supports the design process and validates the proposed design solution. PreConstruction Managers are available to engage at the earliest opportunity and this supports early identification of the right approach which will reduce change and mitigate risk. Our integrated offer means that we can understand the ground engineering delivery challenges while remaining focused on obtaining the best data from the GI to support the foundation solution. Combining the expertise in our disciplines ultimately delivers predictable, right first time, safe solutions for our customers. We started working on Phase 2 of a substantial re-signalling project at the end of 2018 which then carried through into 2019. A risk based approach to the design of the GI, involved a detailed desk study and extensive collaborative walkovers at the start of each phase, allowing the total number of GI positions to be significantly reduced. The works involved carrying out 25 exploratory holes in either the four foot or cessway during weekend possessions. Track hand back engineers were always present on site to ensure the alignment of the running rails were not comprised during the investigative works. Our ability to provide honest and robust prices meant that we eliminated surprises and could deliver predictable outcomes during the delivery of the project.

By adopting digital processes, BAM Ritchies have eliminated paperwork from our ground investigation discipline. The digital approach ensured one hundred per cent data capture and validation in accordance with the specification. Digital data capture enables ground investigation data to be produced and shared more rapidly. Draft borehole records were produced within 24 hours of a borehole being completed allowing draft ground models to be produced rapidly, usually within 24 hours. Phase 2 success built the trust for our customer to return to BAM Ritchies for further phases.

Modular WS Rig with data entry into IPAD

At the end of 2019, we returned to site again for Phases 3 & 4. The scope of works was 14 Nr cable percussion boreholes to twelve metres, 27 Nr windowless samples to 8m using either a modular or standalone windowless sampling rig and 46 Nr hand excavated pits to 1.2 metres with TRL DCP’s undertaken from the base of the trial pit to a depth of 2.2mbgl. The vast majority of the works were carried out during weekend possessions where we had up to seven separate crews on site during any one shift. This work had to be planed meticulously. The great collaborative working relationship ensured that all individual possessions were carried out as planned and without incident.

We are currently working Phase 5. Works started on site in January of 2021 and finished in April 2021. The scope of works is 24 Nr windowless samples to eight metres and 13 Nr hand pits with TRL DCPs.

The drilling equipment is loaded on to track trolleys at the nearest suitable access point, usually a RRAP and then the equipment is pushed to the borehole locations. Using a range of our GI plant including our modular rigs meant that we could deliver wherever the data was needing to be obtained from. Flexibility in our resources ensured that we could meet the challenging schedule of each phase and provide right first time fully validated data through our digital tools and safe, experienced personnel. Being involved with the project through numerous phases meant we had a full understanding of the project goals which focused our GI on ensuring the right investigations were undertaken to meet the needs of the foundation solutions in the future.

Across the rest of the UK we deliver our Ground Investigation services supporting Network Rail and its key delivery partners in understanding the ground in advance of design finalization and delivery. We have undertaken in excess of 50 Ground investigations in the past twelve months to support the management and maintenance of Network rail infrastructure and earthwork assets.

Continuity of work through the project lifecycle means that we have invested in our resources ensuring that we are equipped to meet the site challenge and that our British Drilling Association (BDA) Audited Drillers continue to raise the standards in GI delivery. Our broad geotechnical expertise supports the ground investigation teams in collaborating to ensure the GI is designed correctly to provide the answers needed for the solution design and delivery, this includes the inclusion of test/trial works of the proposed solution.

Our UKAS Laboratory technicians support the teams checking that the samples selected, and testing detailed will meet the needs of the designers and identifying opportunities for improvement or reduction in the field work.

Our Lead drillers and foreman are the key team members when projects are being planned. They have the years of experience to ensure that access is suitable, logistics are arranged, and methodology is agreed. This focused, early involvement means we can provide the predictable performance necessary working on Network Rail property.

A common theme for our ground investigation work is the assessment, monitoring and understanding of earthwork slopes to ensure their future performance and stability. This requires us to be adaptable to all site conditions and be agile in our delivery. We use low bearing pressure plant to get us to the sites, minimizing our impact and reinstatement. We then choose from a selection of modular, reduced height, traditional CP rigs, rotary rigs, window sampling rigs and slope rigs to provide the data from exactly where it is needed. We can also adapt our drilling methods to suit the conditions encountered. If more data is needed, then we work collaboratively to achieve more with our customer in safe and sustainable way.

With our rope access capability, we can get even more slope data quickly without the placing of drilling rigs on slopes. We are flexible regarding the instrumentation installations and are investing in innovative digital solutions to support real time monitoring of earth work assets. This maximises the investment made in the GI to protect from ground problems in delivery. Every sample that comes out of the ground is bar coded so that we have true cradle to grave traceability of all our samples. This prevents data loss and supports programme management so at all times we know where every sample is on its journey towards test result.

Delivering GI works is challenging but delivering them during a pandemic makes this even more so. We have adapted working practices and methodologies; we have innovated, and we have kept our people safe and healthy throughout the past twelve months. We are coming out of this crisis as a better business and ensuring that critical Network Rail infrastructure remains operational and safe for all to use in the future.

Company profile BAM Ritchies is the specialist geotechnical division of BAM Nuttall Ltd.; one of the UK’s leading civil engineering contractors and an operating company of the European construction group Royal BAM. BAM Ritchies started business in Scotland over 55 years ago in 1963 and is now one of the country’s leading and award-winning geotechnical contractors. The organisation employs approximately 300 trained and experienced staff.

BAM Ritchies has a turnover of over £60 million carrying out ground investigation, ground engineering, drilling and blasting and concrete techniques: completing contracts up to £30 million in value.

BAM Ritchies operates UK wide from offices in Kilsyth near Glasgow (Principal Office), Warrington, Nailsea near Bristol, and Godstone in Surrey.

RRV loading CP Rig

We have adapted working practices and methodologies; we have innovated, and we have kept our people safe and healthy throughout the past twelve months

Tel: 07740 771075 Email: matt.ewing@bam.com Visit: www.bamritchies.co.uk