Product has been added to the basket
Item has been added to bibliography

WMRG: East West Rail Stage 2 (Bicester-Bletchley) Engineering Geology and Geotechnics

Date:
12 March 2024
Add to my calendar
Event type:
Evening meeting, Hybrid, Virtual event, Regional Group
Organised by:
Geological Society Events, West Midlands Regional Group
Venue:
Virtual event
Event status:
EVENT CLOSED

Time and location

Tuesday 12 March 2024 | Mott MacDonald, 10 Livery St, Birmingham B3 3NU & Zoom Video Conference | 6:30pm start.

Event details

Kate Kendall and Simon Miles have supported in the delivery of the East West Rail (EWR) Phase 2 project, as part of the East West Rail Alliance. Kate scoped and oversaw the ground investigations and subsequent track bed design through the Governance for Railway Investment Projects (GRIP) stages 4 & 5. When construction began in GRIP 6, Kate then moved to site as a Site Engineer. Simon joined the project as Chief Geotechnical Engineer to principally oversee the delivery of the main earthworks activities.

The East West Rail Alliance (comprising of AtkinsRéalis, Laing O’Rourke, Network Rail and VolkerRail.) was appointed to rehabilitate the mothballed railway between Gavray Junction (Bicester) and Denbigh Hall Junction (Bletchley). Construction started in 2019 with the enabling works, followed by the main civils works in 2020 which was completed this year. The line is expected to enter into service in 2025.

Kate will take us through the regional context of the geology, as it affected the design and construction of the revitalised railway corridor. She will highlight how the initial ground model was built up from the sources available and how this influenced the development of the civils works design. Kate will also describe how the geological materials used in the original construction of the railway influenced the decisions made about how the new railway would be rehabilitated for its new use and to ensure its longevity for decades to come.

Glacial fluvial deposits over Oxford Clay within a cutting slope at Winslow

Rehabilitating a railway, rather than starting from scratch, poses its own challenges. Simon will explain how the existing earthworks were assessed, almost chain by chain, to understand both the stability of the earthworks and the fill material used in the embankments. Modern standards could not be applied, so the impact of the new works was assessed on a ‘no-worsening’ basis, on the basic understanding that the existing earthworks had already proved themselves capable of supporting a railway over more than a century in service. Where conditions have changed then engineering interventions were applied to bring the railway up to modern standards.

Much of these interventions were driven by a project decision to provide a standard width cess walking route throughout, necessitating the widening of embankment crests, and degraded cutting slopes requiring regrading. New bridges were also provided to replace level crossings (5 road bridges and 10 footbridges), plus a partial rebuild of the Bletchley Flyover, and one box culvert. In addition to these, several challenges became known during the construction period which required additional engineering interventions. These included a seepage issue in a cut face, a collapsing embankment, a bridge in structural distress and a bridge experiencing excessive settlement. There were also early concerns raised over the constructability of the track bed design which had to be overcome.

This presentation will show how geology has been an important consideration through all stages of the project from scoping the first ground investigation through to the construction. Engineering geologists formed an integral part of the site delivery team during construction to ensure that there was an accurate translation of the earthworks and track bed design into construction, identifying issues early on and finding solutions


Slope failure within existing historic embankment during construction works

Speakers

Kate Kendall (Engineering Geologist, AtkinsRéalis)

Kate is an Engineering Geologist at AtkinsRéalis and a Fellow of the Geological Society, currently working towards chartership. She joined AtkinsRéalis as a graduate in 2016 following the completion of an MSci in Geology at the University of Birmingham. Kate has worked on a variety of projects during her career, most notably in the rail sector. Kate has also completed a part-time MSc in Geotechnical Engineering, graduating in 2022. Combining geology and geotechnics has allowed Kate to develop her skills understanding how the underlying ground influences the engineering decisions taken within both design and construction.

Kate’s work on EWR began when she was a graduate in 2016. At this time she was involved with scoping the ground investigation, followed by becoming part of the trackbed design team. In 2019 Kate took over as ground investigation supervisor. During her time supervising the GI, Kate built up a relationship with the Alliance civils team who were starting the project enabling works. As a result of this, Kate was then asked to join the site delivery team as a Site Engineer in 2020. Her work started as supervising the construction of the temporary compounds and haul roads and managing material movements. She was then promoted to Section Engineer and lead a team of engineers and managed sub-contractors delivering the construction of the earthworks, trackbed and drainage. 


Simon Miles (Chief Geotechnical Engineer, AtkinsRéalis)

Simon is a Chief Geotechnical Engineer at AtkinsRéalis, a Chartered Engineer and a Fellow of both the Institution of Civil Engineers and of the Geological Society of London. Simon’s experience majors in large infrastructure projects, predominantly in the United Kingdom.
Simon was asked to join the Alliance in March 2021 ‘to de-risk the delivery of the earthworks packages and ensure that they are delivered within one earthworks season’, as it was imperative to the success of the entire project that this was achieved. He subsequently assumed further responsibilities, taking over the Alliance Responsible Engineer (ARE) role for Offline Earthworks and Foundations when the incumbent left the project, and becoming the de-facto leader of the geotechnical engineering team within the construction supporting Site Design Team, and mentor to the many Atkins Engineering Geologists seconded in to the Delivery Teams as Section Engineers.

As Chief Geotechnical Engineer to the Alliance he became responsible for all geotechnical design aspects of the project delivery and oversaw several important design interventions necessary to solve emerging issues with the delivery of the project which would otherwise have threatened the programme. Some of these will be discussed in the presentation. He also de-risked the earthwork hand-back process (into Network Rail maintenance) by undertaking to complete the initial earthworks inspections in-house, using the resources already available to the project, and so protect the programme. The alternative would have been for NR’s contractors to do it as part of their annual work bank, which could have delayed the process by many months and taken it out of the control of the Alliance.


Registration

To reserve a place please email the committee at [email protected]. We will respond in advance of the meeting with the relevant log in details.