Article

Q&A with Molly Kirven

- by
Tags: Featured

Name: Molly Kirven

Job title: Carbon Engineer

Company: Balfour Beatty

Can you provide an overview on your background, current role, and responsibilities?
My background studies lie in BSc (Hons) Geology and MSc Applied Petroleum Geoscience, whereby my thesis focused on renewable energy potential using carbon capture and storage and geothermal energy. From university, I transitioned straight into the construction industry at Balfour Beatty Ground Engineering. I began as a Contracts Engineer and transitioned to a Design Engineer, of which both roles predominantly focused on precast driven piling. Recently, I moved to Balfour Beatty Major Projects as a Carbon Engineer, whereby I work on carbon estimating for tenders, and give project delivery teams support with reporting carbon actual data.

What attracted you into the industry?
I am fascinated with the different tools and mechanisms we can use to work with the ground and construct infrastructural creations with rapid impact. Construction yields tangible results quickly, allowing you to see your work take shape right before your eyes. The construction and engineering industry provides great opportunities to be involved in various projects of different scales. Whether it’s creating sustainable buildings, enhancing communities, or improving infrastructure, all of these play a role in shaping our society and environment.

Can you talk us through your poster design and why you decided to focus on carbon and piling?
Piling has been a large focus in my career journey, and a discipline where I have been able to proactively support sustainability trials and changes, showcased on the poster. These include aiding in creating the sustainability action plan for Balfour Beatty Ground Engineering, analysing pile wastage on precast driven piling projects, and comparing timber vs plastic packing choices. Carbon can act as a measurable tool to visualise the emissions we produce through a whole project lifecycle. It can demonstrate the impact we have and is a key metric for how sustainability can be measured.

Why are you passionate about sustainability?
In my perspective, sustainability embodies positive change for our communities and environment. I am passionate about sustainability as it provides an opportunity to enhance our past and current practices to alternatives which could have a better global impact for future generations.

What would you like to see being done to improve sustainability in the sector?
It would be great to see the industry striving for accurate carbon reporting through a whole project life cycle to understand how we can choose the best options on a per project basis. Through understanding carbon hotspots, and evaluating the best options per project, the most optimum safety, design, engineering, cost, and carbon choices can be made.

How did you find the AGS Annual Conference?
The conference was amazing! It was great to see the theme of sustainability interwoven throughout the day event. I particularly enjoyed the presentations discussing:

    • Carbon calculators and a case study for piling
    • Sustainable finance and pensions
    • Sustainable earthworks practice on major civil engineering projects

All presentations provided ways in which we are and can embody sustainability into the work we do.

What advice would you give to other Early careers professionals?
Where you can be proactive, go for it! There are so many opportunities out there that aid in your growth as an early careers professional, and simultaneously expands your network with individuals you may not usually meet in your day to day role.

Article Sustainability

Do geotechnical engineers truly understand sustainability?

- by
Tags: Featured

Photograph taken during restoration of the Walthamstow Wetlands (Ramboll, 2016)

As an industry, we need to widen our sustainability focus away from carbon management and further afield to include biodiversity, nature-based solutions and climate adaptation. Our six practical steps that you can follow as geotechnical engineers to implement the wider aspects of sustainability effectively are as follows:

  • Improve your working practices by upskilling yourself and your colleagues in the broader principles of sustainability.
  • Engage your workforce and equip them with the skills they need to design sustainable and climate adaptable solutions.
  • Be open to non-traditional approaches and innovative ideas and encourage research in industry applicable solutions on your projects focusing on biodiversity and nature-based solutions.
  • Consult ecologists at preliminary stages in your projects.
  • Engage with researchers into the use of new materials for construction or the adaptation of existing processes utilising constituents that enable biodiversity net gain.
  • Most importantly, don’t wait for someone else to ask you to consider the many aspects of sustainability, take the initiative yourself, and educate your Clients in the process.

We hope that you come away from this article inspired to think more broadly about sustainability.

The scope of sustainability within the ground engineering sector in the UK is developing as Clients, Contractors and Consultants start to take more responsibility to reduce the negative environmental and societal impact that the construction industry creates. The focus within sustainability for the last decade has been on calculating and reducing carbon on projects from materials, transport, and operations. Despite the progress geotechnical engineers have made in this area, we seem to have forgotten that the term ‘sustainability’ encompasses so much more than carbon management and it is pivotal that these other aspects of sustainability, including biodiversity and climate resilience, are considered.

As geotechnical engineers, we have influence on a wide variety of multi-disciplinary construction projects and engage in all stages from outline planning to construction. Therefore, we are in an advantageous position to promote and incorporate the wider themes of sustainability into our designs. It is important that we don’t rest on the sustainability actions of other disciplines but make our own impact as a profession and contribute to the UN Sustainable Development Goals across a range of projects.

There is minimal research or discussion on how ground engineering can beneficially impact biodiversity and embed climate resilience into our designs and in this article we aim to encourage these lines of conversation and pose questions to the ground engineering sector to deliver a more holistic approach to the delivery of sustainable design solutions.

Biodiversity, short for “biological diversity”, is a term used to describe the variability of life on Earth. In recent times, the importance of biodiversity net gain (BNG) has been stressed in the civil engineering sector, with at least 10% BNG becoming a legal requirement for any projects requiring planning permission as of January 2024. This means that these developments must increase the biodiversity value of their sites by 10% on project completion.

In our line of work we have the potential to cause biodiversity loss when developing sites. When constructing linear infrastructure, if not enough care is taken to preserve biodiversity we could cut through habitats displacing species; or we could create barriers to groundwater using embedded walls impacting nearby habitats due to reduced groundwater flow. If we don’t change the way we work, we will continue to contribute to the biodiversity crisis, which is closely linked to the climate crisis. As an industry, we need to adapt our typical working practices to embed biodiversity net gain through the whole life of the project alongside effective carbon management.

At Ramboll, we are focused on considering the potential for biodiversity net gain in our projects. One exemplar project was the Walthamstow Wetlands in London, which won the GE Sustainability Award in 2018. The wider project had impressive biodiversity accomplishments, restoring valuable wetland area in an urban environment. However, the geotechnical design itself also contributed to improving the biodiversity of the site: an earth retention scheme was designed using timber kingposts and geotextiles as opposed to sheet piles or gabions. Due to the flexibility of the geotextiles, the material could easily imitate natural flowing lines. The geotextiles were also porous, allowing water to flow through the structure, preventing the water from stagnating. The short construction programme required to install this geotechnical scheme also meant that the bird-nesting season was not impacted. As well as offering a low carbon solution, this project also considered the wider aspects of environmental sustainability.

As part of the foundation design of offshore wind turbines, at Ramboll we are currently researching into offshore habitat creation, which will aim to improve the biodiversity of the oceans by supporting UNSDG 14 – Life Below Water. Offshore wind farms can become havens for marine life as the foundations below sea level can become artificial reefs and offer new marine habitats. Scour protection measures can be used to improve biodiversity, by using precast concrete units with cavities for life to inhabit and materials that mimic natural chemical substrates. These measures encourage marine growth around foundations, with the possibility for mussels and anemones to colonise the foundations over time.

Marine habitat after the installation of OWTs; Illustration by Hendrik Gheerardyn from S. Degraer, D. A. Carey, J. W.P. Coolen, Z. L. Hutchison, F. Kerckhof, B. Rumes and J. Vanaverbeke, “Offshore wind farm artificial reefs affect ecosystem structure and functions,” Oceanography, vol. 33, no. 4, pp. 48-57, 2020.

However, it is important to consider the negative impacts that are inherent in the foundation design and mitigate these where possible. Marine ecosystems can be disturbed by the noise and vibration produced when piles are driven into the seabed. There are several methods that can be used to mitigate the noise generated, including physical barriers, bubble curtains and viscous dampers (cushions). A combination of these techniques can be applied in addition to vibro-hammer systems for pile driving which are significantly quieter. These techniques all aim to minimise the impact of construction to local wildlife.

Whilst some modern civil engineering projects have goals for biodiversity net gain, the input that we have contributed as geotechnical engineers to date has typically remained a traditional approach. We as an industry need to push ourselves to contribute to biodiversity net gain as part of sub-structure, earthworks, and foundation design, rather than waiting for other disciplines to achieve net gain on our behalf. So, in addition to the above examples, what can we do as geotechnical designers? Our advice to you is as follows:

  • Minimise your project footprint area. This can be done by increasing embankment slopes and utilising sheet pile walls instead of solutions that require more space. This will minimise the impact on the biodiversity of the site; however, you should also be aware to consider the carbon footprints of the scheme options.
  • Avoid regrading areas unless necessary; otherwise, design earthworks suitable for plant growth and habitat development through consideration of slope angles, provision of suitable drainage/irrigation and effective replanting through engagement with ecologists on appropriate native planting mixes.
  • Engage early with ecologists prior to finalising the design for the project. Ecologists are much more likely to be able to provide cost-effective and valuable solutions for biodiversity at earlier stages of the project.
  • Consider your impact on biodiversity when planning ground investigations and site walkovers, regardless of the scale of the project.
  • Source responsible materials. Consider the embodied ecological impact of materials caused by the extraction and manufacturing process (https://ukgbc.org/our-work/topics/embodied-ecological-impacts/) in addition to the embodied carbon of those materials. We should be reviewing the supply chain of the materials we are specifying and ensuring that materials are recycled/re-used wherever possible.
  • Consider the materials you are placing in the ground and the impact they may have. For example, consider the material’s chemical composition and its likelihood for releasing microplastics, and whether a retaining wall which could create a groundwater barrier is required or if it could be permeable. Use natural materials instead of impermeable concrete, for example, use permeable stone columns instead of piles; or design rafts instead of piles to prevent interference with aquifers.

More sustainable geotechnical solutions can not only be lower in embodied carbon, but can also be nature-based, improving the biodiversity outcomes of our projects. Nature-based geotechnical solutions can be defined as primarily geotechnical designs that additionally protect, sustainably manage, and restore natural ecosystems. A practical example that is within our reach is designing slopes for embankments with planting and vegetation and incorporating the benefits of mechanical reinforcement from roots and increase in suction from evapotranspiration. This not only reduces the overdesign of slopes but also, if landscaped correctly and using native plants, can generate a biodiverse geotechnical solution based on nature. To achieve an immediate benefit of this solution it may require the plants to be imported as shrubs rather than seeds so that the vegetation is established more quickly. Similarly to this, planting of trees in specific locations can be a sustainable and nature-based solution to landslide prevention.

An emerging field within ground engineering, outside of carbon management, is the use of bio-inspiration to address geotechnical stability issues. However, these solutions are not common and require assessment of the relative spatial and temporal scales between biological systems and engineering. Biological processes typically occur on a much smaller scale and at shallower depths, hence, the magnitude of pressures is different, as are the strength and stiffness properties. These factors make it challenging to apply biological processes to geotechnical solutions. However, a good example of this is the use of bio-cementation for soil stabilisation or ground improvement. Bio-cementation uses microbially induced carbonate precipitation (MICP) to produce calcium carbonate (CaCO3) to increase the strength and rigidity of granular soils, improving the strength properties by improving shear strength and compressibility (Safdar et al, 2021). Ramboll are facilitating a Network Rail project with Southbank University where bio-cementation is being trialled on 30m of new embankment over a horizon of soft peat. If this process becomes more widely researched, it could become an innovative way of stabilising weak soils without the use of imported fill or carbon intensive binders.

The biocementation process. Diagram by ACS Sustainable Chem. Eng. 2017, 5, 6, 5183–5190, Publication Date: May 16, 2017. https://doi.org/10.1021/acssuschemeng.7b00521.Copyright © 2017 American Chemical Society

When considering geotechnical problems, in addition to reducing embodied carbon and improving the biodiversity of our projects, we must design for the future climate. Adaptation of our geotechnical designs to climate change is becoming more critical as we experience ever more frequent extreme weather events and rising global temperatures. Climate resilient designs can be environmentally and economically more valuable, increasing design life, reducing the need for demolition and replacement of assets and, decreasing the risk of engineering failure if a one-off weather event occurs.

Implementation of climate models in geotechnical design could include fluctuating or higher groundwater levels caused by sea level rise and flooding or conversely, lower groundwater levels caused by droughts and the over-extraction of groundwater. Additionally, we may need increased corrosion protection for steel marine structures caused by acidification of the oceans.

In the UK, shrink-swell of over consolidated clays is already an issue for structures, and this will only increase with climate change increasing rainfall and temperatures. Research into the use of natural material barriers (up to 1000mm thick) to reduce the increasing magnitude of movements of shrink-swell clays is being conducted by Climate Adaptation Control Technologies for Urban Spaces (CACTUS) not only as a way of adapting to climate change but also creating a nature-based geotechnical solution. Additionally, changes in the climate can affect the freeze-thaw cycle, impacting roads, pavements and railways requiring changes to sub-base design.

Another way of looking at climate adaptation could be the use of modular design. Marine walls for sea defences can be built by modular design allowing the height of the wall to change. Could this be applied to retaining walls in ground engineering?

We should be encouraging Clients to consider the impacts of climate change on their assets by highlighting to them both the environmental and economic long-term benefits of choosing the sustainable option. Widening our sustainability focus away from carbon management and further afield to include biodiversity, nature-based solutions and climate adaptation will bring great benefits to us as an industry, and to the planet.

Article produced by Marla Gillow, Senior Geotechnical Engineer, Ramboll and Meggie Cassidy, Principal Geotechnical Engineer, Ramboll

Article

NHBC’s new Performance Standard for Building on Engineered Fill

- by
Tags: Featured

NHBC’s commitment to investing in high-quality research, products, and Standards has always been key to supporting the industry in maintaining and improving quality. With around 70,000 plots registered for Buildmark Cover annually on land previously considered Brownfield, NHBC’s commitment to ensuring safe and high-quality developments on these sites cannot be overstated.

In 1999, NHBC became the first UK warranty provider to offer extended warranty provisions for contaminated land. It introduced a new Chapter 4.1 named “Managing Ground Conditions,” which outlines the acceptance requirements for warranty and subsequently published Research & Development  Publication 66 to guide safe housing development affected by contamination.

Although a slow start for those unfamiliar with it, the house-building industry got on board, and with scientific advancements, improved government policy, supporting guidance, and help from specialists like AGS members, the understanding of Contaminated Land Assessment has greatly improved. As a result, contamination claims are now rare.

Recently, the quality and reduced input of geotechnical expertise within submissions has been a concerning trend noticed by the NHBC Land Quality Service team, especially for schemes involving earthworks to prepare sites for residential development. Although NHBC sees exceptional work, we are increasingly seeing evidence, reporting, or designs that are limited or show a lack of understanding of geotechnics.

It is unclear why this is happening; it could be due to an early emphasis on addressing environmental concerns. These are routinely and rigorously enforced through planning but, as a consequence, can often distract applicants or the necessary investment away from the geotechnical needs until the planning consents are secured and certainty of development investment can be realised.

Geotechnics within the house-building industry may be considered less innovative or exciting than other sectors, leading to fewer specialists working in this field. However, as the easier-to-win schemes become less common, this couldn’t be further from the truth. Building more homes on marginal or brownfield development is undeniably becoming more frequent. Indeed, NHBC regularly encounters submissions for warranty on challenging and complex sites. These vary from Greenfields that require flood alleviation measures and significant land raising to existing infilled ground such as former quarries or historic landfills, old collieries, and areas with past industrial land use.

Our registered builders and developers must comply with the technical requirements set out in the NHBC Standards. The NHBC Standards define the technical requirements and performance standards detail how these can be met for the design and construction of homes covered by Buildmark. NHBC regularly reviews and updates the Standards.​

NHBC introduced a new Standards Chapter, 4.6, this year to deal with the increasing number of sites using engineered fills for low-rise residential structures, external works, and infrastructure or below raft foundations on sites with shrinkable clays and trees instead of deep trench fill foundations.

Although Chapter 4.6 may not provide any new information for experienced geotechnical professionals, it does introduce a new performance standard for house building. It gives guidance essential for meeting the technical requirements to achieve NHBC acceptance. It also re-emphasises the significance of geotechnics and the importance of obtaining quality data to enable a suitable design for and to address foundation quality after earthworks.

From January 1st, 2024, any new earthworks tender required to support building foundations where an NHBC warranty will be requested must comply with the performance requirements of Chapter 4.6. From January 2025, all new foundations on engineered fill will be expected to comply fully with the requirements and guidance of the new chapter.

NHBC Standards 2024 became effective on January 1, 2024. Chapter 4.6 includes 13 main performance clauses and spans across 28 pages. At the beginning of the chapter, a flowchart is provided to help practitioners navigate the document.

The clauses cover various requirements relating to competence, geotechnical investigation, ground models, appropriate laboratory testing, compliance testing, earthworks specifications, verification, and reporting expectations. Moreover, this chapter also includes significant requirements and considerations regarding acceptable foundations and design. The main requirements are that:

  • Engineered fills do not settle excessively or have the potential to cause excessive differential settlement between properties founded upon the fill and external areas.
  • Engineered fill and the underlying ground supporting building foundations shall limit the total building settlements to less than 25mm and minimise angular distortion or tilt to 1:400.
  • The design and detailing of foundations, infrastructure, and external works suit the placed fill and underlying ground conditions, considering the overall ground model and any geohazards beneath or nearby.

The introduction of Table 8 is an exciting addition in the new chapter. It provides information on foundations that may be suitable based on three different scenarios with varying standards of fill.

 

But a word of caution: Practitioners should only use this table as guidance. They are reminded not to rely upon it to justify a less robust foundation solution if geotechnical risks remain outside the fill and to remember that all foundations must be designed on a site-by-site basis, considering all relevant geotechnical risks.

If buildings are on piled foundations, it is essential not to overlook considerations regarding any differential settlement between the houses and external areas in designing any services.

Practitioners must remember what is covered and what is not covered in Ch4.6. For instance, assessing historic fills is not included in Ch4.6 and would require additional guidance from other sources. Long-term monitoring or loading trials may sometimes be necessary to determine performance.

If you are unsure whether your site is suitable for residential development, NHBC provides a Land Quality Service. This service involves close collaboration with stakeholders, enabling early engagement and supporting those seeking approval of solutions. We ensure that the risks associated with land quality and foundation solutions are appropriate for the entire 60-year design life of the properties.

NHBC Standards 2024 can be easily accessed online for free.

Article provided by Karen Thornton – NHBC Land Quality Service Manager FGS, MCIWEM, MCABE

 

Article

NEC Option X29 – A positive step to tackling climate change, but not without its risks

- by
Tags: Featured

Introduction

The recent years have seen sustainability and climate change move to the forefront of the construction industry, with these topics being considered by many engineers, contractors and consultants in their working practices.

With a view to ensuring that climate change requirements are reflected in contracts and with a view to drive construction professionals to focus on sustainability and climate change, the NEC introduced a new secondary Option clause for climate change.  Option X29 (climate change) has been drafted as a Secondary Option that parties using the NEC4 suite of contracts can choose to include in their contracts.  Published in August of 2022, Option X29 represents a very positive step in helping the construction industry help tackle climate change.

Since its publication there has been a steady increase in its adoption, with a further increase in the use of this clause expected as practices focus on setting their climate change goals and missions.  However, its use does not come without some additional risks and liabilities that parties intending to use this option clause should be aware of.

In this article, we discuss the use of Secondary Option X29, its key features and the risks that may arise when Option X29 is selected to apply in an NEC4 contract.

Key Features

Option X29 introduces several key elements that will help the construction industry address climate change in their contracts.  Discussed below are some of the key features that will need to be considered carefully when navigating Option X29 if selected to apply on a project.

Climate Change Requirements

The Scope must specify the Climate Change Requirements that must be complied with. This means that any contractor/consultant will be required to comply with the Climate Change Requirements in order to Provide the Service in accordance with the Scope (as is required under the NEC4 PSC, for example).  Therefore, a failure to comply with the requirements will be a Defect if it is considered to relate to the services/works and consequently will require rectification at the contractor’s/consultant’s own cost.

It is therefore essential that careful consideration is given to the contents of the Climate Change Requirements to ensure that they are both achievable and do not place undue risk on the parties.  For example, the Climate Change Requirements will need to be carefully reviewed for obligations that may cause an insurance concern, such as a fitness for purpose obligation.

Climate Change Plan

The Climate Change Plan is to be devised by the contractor/consultant and is required to set out the contractor/consultant’s strategy for achieving the Climate Change Requirements (e.g., setting out stakeholders, roles, timescales. key milestones, tools and tasks to get there). The intention behind the drafting is for the plan to be updated as and when instructed and required. The form of the Climate Change Plan will be for the parties to decide and may be set out in the Climate Change Requirements.

It will again require very careful consideration to ensure that the Climate Change Plan proposed on a project is both appropriate and achievable.

An open dialogue with clients on the Climate Change Requirements and Climate Change Plan on projects will be important (and should be encouraged) to ensure the documents and requirements contained therein are palatable and workable for all involved.

Performance Targets 

The drafting of Option X29 includes the provision of a table for setting out any performance requirements and the targets that must be met. This provides a regime for measuring compliance with specified performance targets, for which the client may set out financial incentives.

It is for the parties to set the targets in the Performance Table, which can be in any form that they wish, whether this be through implementing key performance indicators (“KPIs”) or through providing specific values or requirements that are to be met.  The targets may also go beyond the Climate Change Requirements.  Given the flexibility of the table provided for in the drafting of Option X29, it is key that any targets entered are objectively measurable, with a clear methodology.

If the targets in the Performance Table are not met, the contractor/consultant will be required to pay the amounts stated in the Performance Table to the client, whilst achieving or exceeding the targets will entitle the contractor/consultant to a payment in accordance with the Performance Table.

Whilst largely intended to be a positive incentive mechanism to encourage parties to meet the targets, it will be important that the Performance Table is carefully reviewed to ensure that ideally no negative incentives/damages/penalties are included.  Any negative incentives/damages/penalties are akin to liquidated damages, which are typically excluded from the scope of cover under a consultant’s typical insurance policy.

If the Performance Table includes any KPIs, these should be reflected in the contractor’s/consultant’s commercial model (e.g., pricing etc) for the project. It will be important that any KPIs are understood and reviewed to ensure they are acceptable (and are achievable – especially where any negative incentive/damages/penalties are proposed).

Contractor’s/Consultant’s Proposals 

One positive feature of Option X29 is that the contractor/consultant can propose changes to the Scope if they believe that they can reduce the environmental impact of the lifecycle of the asset.

The process requires the proposal to be ratified by the client before any change can occur. Whilst the client does not have to accept the proposal, it is hoped that this feature will be positively accepted by clients to reduce environmental impacts on projects.

Limit of liability

The standard NEC4 liability provisions introduce a concept of ‘excluded matters’, for which liability is unlimited.  Any amounts payable by the contractor/consultant in accordance with the Performance Table will be an excluded matter and therefore excluded from the cap on liability (if secondary Option X18 is used). This means that liability for payments of any amounts in the Performance Table is unlimited.

The potential of exposure to significant and/or unlimited liability under this clause emphasises the need for careful consideration to be given to the Performance Table, particularly if any negative incentives/damages/penalties are included.

Conclusion

The intention of this clause is a positive step in helping the industry tackle net zero and other related climate change and biodiversity goals, and its inception by NEC is one that should be lauded.

However, it is not a “complete solution”, and parties will need to consider carefully how it should be used and whether any amendments are necessary to balance commercial needs and reflect project-specific standards.  The use of this clause and the implications therefore require a great deal of thought.

Option X29 has been drafted in a deliberately flexible manner that enables the parties to decide upon the approach that they want to take on a project-by-project basis. This means that project specific amendments may be made to the standard positions discussed within this article. Therefore, the drafting (and implications) of Option X29 will need to carefully considered on a project-by-project basis.

However, there are a few key points to highlight in relation to Option X29 before it is used:

  • As mentioned, the clause is not a complete solution that can just be inserted into a contract. It requires a great deal of thought and discussion between the parties as to how it will be used and the targets that will be set. These targets need to be both attainable and measurable for the clause to be used effectively.

 

  • The definitions of Climate Change Requirements and the Performance Table do not include a reference to any of the emerging standards or definitions that we are seeing developed, such as the UK or World Green Building Council’s definition of ‘net zero’.

Whilst the drafting promotes flexibility, it does enable the client to specify the determination of each definition. Contractors and consultants should assess the definitions and metrics for each and every contract that it enters.

  • Consultants and contractors will need to carefully consider the requirements of the clause in line with their professional indemnity insurance policies. As mentioned in this article, there is a risk that some of the documents discussed may contain provisions that are inconsistent with insurance cover.

It goes without saying that the potential benefits that Option X29 (and “green drafting” more generally) can bring may make the effort worthwhile, but it is important that the risks and liabilities associated with and being imposed on the Contractor/Consultant are understood at the outset. Option X29 and “green drafting” more generally, therefore need to be considered carefully as it could lead to additional risks and liabilities being imposed on the contractor/consultant in the guise of tackling climate change.

If you would like any further information or would like to discuss this note or the use of Option X29, please contact the authors.

Article provided by Kathryn Eva (Associate at Beale & Co) and Harry Coates (Solicitor at Beale & Co)

Article

AGS Annual Conference 2024 Summary

- by
Tags: Featured

The AGS Annual Conference took place at One Great George Street, London on 25th April with over 235 delegates in attendance.

Chaired by AGS Chair, Vivien Dent, the conference had eight guest speakers covering a range of geotechnical and geoenvironmental topics with a focus on sustainability. The AGS Working Group Leaders also provided updates about their Working Groups from the past 12 months.

To continue the theme of sustainability, the conference showcased all 21 entries from the AGS’ Early Careers Professional Sustainability Poster Competition, and invited winner, Molly Kirven, (Balfour Beatty) to attend the event. The AGS have also agreed to donate a percentage of profits generated from the conference to Projects for Nature, which is an initiative formed by the Council for Sustainable Business, Accenture, Defra, Natural England, Environment Agency and Crowdfunder, that aims to restore nature recovery in the UK.

Jim Webster (Director at Earthworks and Materials Solutions) opened the conference by discussing what sustainability means in terms of earthworks. This was followed by Tim Rolfe (Director at YES Environmental) who presented on The Role of Quantitative Risk Assessment in Reducing Soil Disposal and Importation at Contaminated Sites. Roseanna Bloxham (Principal Geo-Environmental Engineer at RSK Environment) explored the recent NHBC Foundation research and guidance for the housing sector, focusing on the NF93 report, which looks at the climate change risks impacting building foundations in new housing.

Following lunch and networking opportunities, Mark Hill (Climate and Sustainability Lead at The Pensions Regulator) presented on how the Taskforce for Climate-related Financial Disclosures and Sustainable Disclosures Requirement could impact brownfield and infrastructure sectors from a pensions perspective. Ebenezer Adenmosun (Managing Director at Geofirma and Co-Founder of the Ground Forum Undergraduate Mentoring Scheme) then provided an update on GFUMP and the impact the scheme has made on the industry.

This was followed by a presentation by Marla Gillow (Senior Geotechnical Engineer at Ramboll) and Kalisha Sejpar (Associate at Ramboll) on Case Study: Measuring Carbon from Design to Construction at 2 Finsbury Avenue. Finally, Alan Thomas (Technical Partner at ERM) presented on Insights from the Sustainable Remediation of an Agrochemical Manufacturing Facility.

The Annual Conference concluded with a networking drinks reception in the Great Hall, which was a first for the AGS Annual Conference.

It was a great event and a brilliant opportunity for the industry to gather, network and exchange ideas.

The AGS would like to take this opportunity to thank our speakers and sponsors including Geosense, Igne, Soil Engineering, Groundsure, Equipe, Brimstone, ACS Testing, Maccaferri, Eijkelkamp Fraste UK, Envirolab, Landmark Information Group, i2 Analytical, AFITEXINOV UK, BAM Ritchies, Lankelma, Insitu Site Investigation and Geotechnical Engineering.

Article Data Management

BS8574 – A Guide to Data Management Plans – Webinar Summary

- by
Tags: Featured

On 12th March 2024, the AGS held a webinar entitled ‘BS8574 – A Guide to Data Management Plans’.

The webinar was chaired by Jackie Bland (Principal Ground Investigation Data Manager at Structural Soils and AGS Data Management Working Group Leader), and included presentations from Neil Chadwick (Director, Digital Geotechnical), Tony Daly (Managing Director at Amageo Limited), Simon Miles (Chief Geotechnical Engineer, AtkinsRéalis) and Craig Brown (Senior Data Manager – BAM Ritchies).

Neil Chadwick began the webinar by providing an overview of BS8574, highlighting the requirements for a data management system to provide context for the discussion of data management plans. This was followed by a presentation from Tony Daly who provided a client’s perspective. Simon Miles then gave a presentation on BS8574 from the consultant’s viewpoint. Craig Brown provided the final presentations on the perspective of data management plans from a ground investigation contractor and guidance for preparing data management plans. The AGS Data Management Working Group have produced some guidance for the preparation of data management plans for ground engineering projects, which can be viewed on the AGS website here. The guidance is split into two parts, the first part provides considerations that should be made when writing a data management plan and the second part gives a practical example demonstrating how to meet the requirements with additional notes on considerations for each topic. The webinar ended with a group Q&A.

The event received excellent feedback, with attendees rating it 4.6 out of 5 stars and stating that they would be 4.5 out of 5 stars likely to recommend the webinar to a friend or colleague. Over 96% stated that they had learnt something new from the presentations that could be applied to their work.

A big thank you to all who attended, and to SoilCloud for sponsoring the webinar.

Want to access the recording but didn’t register to attend? AGS Members can access this for free via the webinar archive after logging in to the AGS website. Non-members may also request access via the AGS website for a charge of £30+VAT.

News

AGS Magazine: May 2024

- by
Tags: Featured

The Association of Geotechnical and Geoenvironmental Specialists is pleased to announce the May 2024 issue of their publication; AGS Magazine. To view the magazine click here.

This free, publication focuses on geotechnics, engineering geology and geoenvironmental engineering as well as the work and achievements of the AGS.

There are a number of excellent articles in this issue including;

Geotechnica 2024 – First Speakers Announced – Page 8

We Need To Talk About Groundwater – AGS Conference – Page 12

AGS Annual Conference 2024 – The Review – Page 16

NEC Option X29: A positive step to tackling climate change, but not without its risks – Page 20

NHBC’s new Performance Standard for Building on Engineered Fill – Page 24

Do geotechnical engineers truly understand sustainability? – Page 30

Standards Update: April 2024 – Page 36

Plus much, much more!

Advertising opportunities are available within future issues of the publication. To view rates and opportunities please view our media pack by clicking HERE.

If you have a news story, article, case study or event which you’d like to tell our editorial team about please email ags@ags.org.uk. Articles should act as opinion pieces and not directly advertise a company. Please note that the publication of editorial and advertising content is subject to the discretion of the editorial board.

Article

Early Careers Sustainability Competition Entries

- by

Thank you to those who entered our AGS Early Careers Sustainability Poster competition. We received 21 entries from across 18 different companies, each with their own unique take on the competition brief.

The judges, Vivien Dent (AGS Chair, Environment Agency), Sally Hudson (AGS Past-Chair, Coffey Geotechnics) and Alex Lee (AGS Chair-Elect, HKA) had the challenging task of judging the entries, but were pleased to announce that Molly Kirven (Balfour Beatty) came out on top.

Congratulations to Molly – she’s won a Selfridges hamper, entry to the AGS Annual Conference plus a double page spread within AGS Magazine, showcasing her entry and inspiration behind the poster.

Thank you to all those who took the time to submit an entry – they were all showcased at the AGS Annual Conference and viewed by our 230+ attending delegates.

 

 

Article News Business Practice Contaminated Land Data Management Executive Geotechnical Instrumentation & Monitoring Laboratories Loss Prevention Safety Sustainability

AGS Awards 2024

- by

We’re delighted to announce this year’s AGS Award winners!

Chosen from a select number of AGS Working Group Members, these winners were nominated by their Working Group Leaders in testament to their hard work and dedication to the AGS over the past year.

A huge well done and thank you to the following Award and commendation winners for their extraordinary work and ongoing contributions to the AGS:

Contaminated Land Working Group Award Winners

  • Andrew Tranter, Associate Technical Director at RSK
  • Darren Makin, GI Geoenvironmental Lead at Socotec

Executive Award Winner

  • Alex Dent, Associate Director at WSP

Executive Commendation

  • Alison Nicholson, Geoenvironmental Team Lead, Associate Geoenvironmental Consultant at Buro Happold

Data Management Working Group Award

  • Neil Chadwick, Director at Digital Geotechnical

Geotechnical Working Group Award

  • Katharine Barker, Associate at CampbellReith
  • Emma Cronin, Heathrow GI Senior Geotechnical Engineer at Socotec

Geotechnical Working Group Commendation

  • Paul Roberts, Regional Director, Ground Engineering, UK & Ireland Aecom

Laboratories Working Group Award

  • Will Fardon, Technical Director at Chemtech Environmental

Loss Prevention Working Group Award

  • David Hutchinson, AGS Honorary Member
  • Neil Parry, Director at Geotechnical Engineering

Safety Working Group Award

  • Liz Withington, Principal EngineeringGeologist at CC Ground Investigations
  • Madeleine Bardsley, Technical Director at WSP

Safety Working Group Commendation

  • Owen Seymour, Associate- Engineering Geologist (Geotechnical & Tunnelling) at WSP

Sustainability Working Group Award

  • Vivien Dent, Technical Specialist: Green Growth and Delivery at the Environment Agency
  • Sam Setchell, Principal Engineering Geologist at Jackson Geo Services

 

To view the montage of acceptance speeches from our winners, just click on the video below.

 

 

 

News

AGS Magazine: March 2024

- by
Tags: Featured

The Association of Geotechnical and Geoenvironmental Specialists is pleased to announce the March 2024 issue of their publication; AGS Magazine. To view the magazine click here.

This free, publication focuses on geotechnics, engineering geology and geoenvironmental engineering as well as the work and achievements of the AGS.

There are a number of excellent articles in this issue including;
AGS Annual Conference 2024 – Page 10
AGS Bitesize Guide: Pile design based on calculation – ground model method – Page 16
Calibration of BRE365 soakaway testing – Page 22
Sharing Ground Models using AGSi – Page 28
Site Supervision – Shouldn’t we be specific? – Page 32
Inside: SoilCloud SAS – Page 34

Plus much, much more!

Advertising opportunities are available within future issues of the publication. To view rates and opportunities please view our media pack by clicking HERE.

If you have a news story, article, case study or event which you’d like to tell our editorial team about please email ags@ags.org.uk. Articles should act as opinion pieces and not directly advertise a company. Please note that the publication of editorial and advertising content is subject to the discretion of the editorial board.

Article

BRE365 Soakaway Testing; Discussion on Safety and Alternatives

- by
Tags: Featured

Since 2007 when the first SuDS manual was published, AGS members have increasingly been asked to provide services to support design of sustainable urban drainage systems. The author of this article has been working with the BRE365 test since the 1990s and is still supervising, designing and reporting infiltration rate results to designers from trial pit and borehole methods.

AGS has recently been investigating how our industry manages undertaking and reporting infiltration rates for design of devices for discharge of surface water into land including; soakaways, basins, swales and permeable paving. Amongst members, the almost exclusive method requested by clients is to follow the BRE DG365 procedure as discussed in the AGS article (ref AGS magazine Oct 2021).

BRE DG365 is an empirical methodology for the design of soakaways, which includes the test procedure to provide observational data on infiltration rates. It was not intended for either basins or permeable paving. Because of the sparse nature of the test instructions, how it is carried out and reported can vary between practitioners. Concerns were first raised in the AGS safety working group at the same time as general trial pitting methods came under renewed scrutiny. The geotechnical working group was also requested to look at data quality in context, which resulted in the previous article. It is recognised that AGS members’ risk assessments and method statements on trial pitting may have been extended to cover BRE365 by written procedures to keep inexperienced staff safe in conducting these in-situ tests. Innovations and modifications may also have been made to the BRE365 method, to standardise in-house practice and to avoid taking up excessive resources during what can be a logistical challenge of labour, plant and materials.

This article is intended to build on the previous article, briefly cover the test origins and discuss what alternatives might be possible.

The development of technology of infiltration testing can be traced through publications. The following list shows an incomplete chronology.

1973 BRE151 Soakaways – (also NHBC 5.3.11) Soakaways BRE Digest 151, Watford. Building Research Establishment (Digest 151 is presented currently as a method in NHBC Standards https://nhbc-standards.co.uk/5-substructure-ground-floors-drainage-and-basements/5-3-drainage-below-ground/5-3-11-surface-water-soakaways/ )
1991 SR 271 The Hydraulic Design of Soakaways Report The Hydraulic Design of Soakaways Report SR271 1991 by DC Watkins published by HR Wallingford is available as a free resource here https://eprints.hrwallingford.com/311/ and describes the modelled water flow processes in a soakaway.
1991 (latest revision 2016) BRE365 Soakaway Design Empirical method of soakaway design including test for infiltration rate.
1996 R156 Infiltration drainage – Manual of good practice CIRIA report Report 156 1996 Infiltration drainage – Manual of good practice Roger Bettess BSc PhD MCIWEM. Provides an infiltration test procedure similar to BRE365 but with some variations and extra information.
2007 (Version 6 including 2016, 2018, 2019) C753 The SuDS Manual The current reference for Suds Approval Boards/Lead Local Flood Authorities (SAB/LLFA) in the UK is the The SuDS Manual (C753) https://www.ciria.org/ItemDetail?iProductCode=C753&Category=BOOK&WebsiteKey=3f18c87a-d62b-4eca-8ef4-9b09309c1c91.

BRE 151 & NHBC 5.3.11 involves recording the time for a fixed height of water to drain in a small trial hole. The time t is graphically translated to a soakaway size using correlations which have uncertain/unknown justification.

SR271 indicates that flow in unsaturated ground is different to saturated ground in four main respects (head in the fluid is due to suction, storage coefficient and conductivity are variables, and gravity induces vertical flow), and compares in-situ test results with those obtained from numerical modelling using Richards modified equation. By relying on testing at the proposed location of the device and use of bulk factors of safety the design philosophy is confirmed to be experimental. Uncertainties do not include the possibility of significant variations in soil type at the location of the test (and by implication the soakaway).  This may be a point of contention with some practitioners used to UK shallow geology.

The work in R156 was carried out by HR Wallingford under contract to CIRIA in the period October 1991 to March 1995. R156 cites many other sources of information (BRE were part of the steering group represented by Dr John Powell). The extra information in R156 does help to confirm the experimental nature of the test specific to the location of the proposed infiltration device and the intrinsic adoption of bulk safety factors. This requires that the location of the device (test site) must be chosen by a designer.

C753 probably deserves an AGS article on its own. In Chapter 01 – The philosophy of SuDs, the 3-D conceptual model in Figure 1.2 models the underlying geology as a grey monoblock rather than layers of strata for example which is a shame. In nearly 1000 pages of C753 the word geology occurs 16 times, frequently associated with land stability; ecology is listed 42 times and archaeology once. Possibly geology is not that important to the delivery of SuDs, but is regarded as a constraint. AGS members are probably most interested in SuDs Section 25 Infiltration design methods, and specifically 25.3 Infiltration Testing Methods and Appendix B.4 Infiltration Assessment. Appendix B.4 includes a checklist (Table B6) intended for use by the approving bodies (and the designers) which assumes competence in ground assessments, which may not be available in all design teams. There are plenty of apparently excellent SuDS case studies, but they don’t generally include details of the geology or infiltration tests and how infiltration challenges were overcome. Competent ground assessors would surely benefit designers.

Discussion

The SUDS manual is probably the most important document for members and designers to understand. Unfortunately, members may only be requested to perform the BRE365 test and nothing else.

In my experience, over-winter (wosrt-case) water level monitoring has been more frequently requested by designers indicating a more favourable approach to ground modelling.

It seems the current SuDS manual was written with Eurocodes in mind, but apparently not integrated possibly due to the embedded modelling from SR271 between test, device design and bulk safety factors. Mention of 14688 & 14689 in the B6 checklist are assumed to enable initial permeability assessments to be made by designers from descriptions correlated to published permeability values. In such cases, ground practitioners might note subtle fines content descriptors in coarse soils which could lead to significantly different engineering properties in tests. Designers and regulators might just see either SAND or CLAY and get a wrong outcome.

It is tempting to assume that permeability and infiltration approximate to the same value but that may not be accurate. Scale & geology variations mean that measurements of permeability in small laboratory samples cannot be representative unless part of a fully developed ground characterisation. In any event permeability cannot be used in exactly the same way as infiltration rate due to the modelling/empirical link between test and the device design. It is the device (soakaway/basin) that has a characteristic design value of infiltration (usually the tested soil worst-case), and potentially too conservative if water will find preferential pathways and bulk safety factors are deployed. Whilst the SuDS manual includes falling head tests in ISO 22282-2:2012 as acceptable in principle, there are conditions and limitations. There may be parallels here with the recent AGS presentation on sample disturbance where taking a few high quality and well-selected data sets might be considered “better” than many more data of variable/unknown control. We might assume that falling head test data should be presented as a part of a full Eurocode characterisation of the ground to be compliant. Simply replacing isolated infiltration data from a trial pit with more falling head tests in a borehole is likely inadequate, although potentially safer for operatives and might use less resources.

Use of boreholes as a device for obtaining infiltration data is a natural ambition for AGS members seeking compliance with standards and health and safety. However, if the depth of infiltration is limited, for example, by the Environment Agency through planning to less than 2m depth (as been the experience of the author) then the preference for using trial pits is understandable. A daisy-chain or in series hierarchy approach from initial water harvesting to bulk basin attenuation with limited shallow infiltration finally to deep soakaways for overflow situations might be good design but is not necessarily supported by case study.

There is also Geotechnical investigation and testing – Geohydraulic testing – Part 5: Infiltrometer tests (ISO 22282-5:2012), which exclusively describes the various types of ring infiltrometer test; single or double ring, open and closed. In these tests, flow through the side is not included, therefore not compatible with the SR271 modelling. However, the ring infiltrometer would logically be more appropriate for plane devices such as permeable pavements if the modelling is different. Again in my experience, It seems shallow depth BRE365s is preferred by designers for permeable paving.

Conclusion

From this discussion, there are no obvious “off the shelf” replacement alternatives to the BRE365 test to recommend to members.  Noting the fundamental link in the digest between the design output and the in-situ test. However, practitioners might note that although BRE365 was most recently updated in 2016, Bettes 1996 (R156) is the primary reference in the SUDs manual.

The alternatives to BRE365 should be ISO 22282-2 or ISO 22282-5 neither is wholly recommendable (or likely to be accepted nationwide) as a direct replacement.

To support a sustainable agenda wider use of understanding ground models at the initial stage is recommended and not to rely on limited study & a small data set of BRE365 tests. A site where there is a 3m thick layer of clay over 10m of unsaturated permeable sands; three 2m deep tests would indicate infiltration is not possible resulting in the design of an attenuation basin occupying potentially unnecessary space and wasting other resources. A conceptual model, initial investigation and targeted deeper BRE365 tests may result in a much more sustainable scheme.

BRE365 and the SuDS manual could be updated to include the modern context such as health and safety including the gravel filling of test pits, responsible use of resources/logistics and adoption of dataloggers. Guidance could be provided on the benefits of a good geological characterisation and what benefits could be gained from having representative/characteristic high quality data rather than the adoption of worst-case values because of limited data. More case studies might be expanded to include problem solving where poor draining geology has been overcome by engineering for example using linear features which can intercept preferential pathways in variable soil/rock. Or combined systems featuring infiltration devices of limited/known capacity linked to bulk attenuation and final overspill into deep borehole soakaways.

The AGS is keen to hear examples of good practice for safely undertaking the BRE365 methodology and examples where SuDs design has been informed by alternatives to the conventional BRE365 method.  Please contact the AGS at ags@ags.org.uk with examples or comments.

Article provided by James Harrison of 4D Geo Limited

Article

INSIDE SOILCLOUD

- by
Tags: Featured

Name: Tomasz Daktera

Job title: President

Company name: SoilCloud SAS

What does the company do and what areas does it specialise in?

SoilCloud provides a Geotechnical data management web software (AGS compatible). We are leading the digital transition of geotechnical engineering in France (over 60% of all geotechnical data and tests in France are being analysed by our system). We are also present in the UK and 5 other countries around the world.

Where is SoilCloud located?
Our Headquarters are located in France, Paris.

How many people does the company employ?
We are 7 fascinated engineers at SoilCloud.

How long have you worked at SoilCloud?
Together with Lucas Janodet, we have co-founded SoilCloud in 2018.

What is your career background, and what enticed you to work for SoilCloud?
Together with Lucas Janodet, both geotechnical engineers, we have founded SoilCloud to engage the digital transition in the industry and to make more efficient.

What is your current role within SoilCloud and what does a typical day entail?
As president, I am dealing with medium term and long projects as well as product development, global strategy and international sales.

What are the company’s core values?
Our core values are related to the way we operate. We put our clients and their needs and feedback first.

Are there any projects or achievements which SoilCloud are particularly proud to have been a part of?
In 2023, we have won the Solscope Innovation award, which is the most prestigious prize in geotechnical engineering in France (distributed once every two years). SoilCloud’s software and vision has been recognized as a global change in the whole French geotechnical industry.

How does SoilCloud support graduates and early career professionals who are entering the industry?
In our team, one of our IT developers is an apprentice still attending school 2 days a week. Young professionals have a great amount of positive energy which encourages the whole team to work together to deliver a great product.

Why do you feel the AGS is important to the industry?
As a leader in the digital transition of the geotechnical industry, SoilCloud is strongly promoting the AGS format around the world. The AGS format is something that was ahead of its time in the previous years and the industry is, just now, understanding the great added value of it.

What are SoilCloud’s future ambitions?
2000 satisfied users in 2024. Today, we have about 1800 users and counting.