Consortium for Research into Congested Underground Space (CoRCUS)

About CoRCUS

The Consortium for Research into Congested Underground Space (CoRCUS) have extensive experience – and a sound appreciation – of the challenges posed by new construction in congested underground spaces in the urban environment.

Working around existing infrastructure and buried assets is increasingly unavoidable in urban environments, and the need to protect these assets from damage can significantly influence, and sometimes hinder, the development of new schemes. These issues affect the majority of new underground construction schemes in urban areas; any new shafts or tunnels needed for such an enterprise are necessarily in close proximity to existing station structures.

Furthering the understanding of the ground’s response to congested underground construction events and the assessment of the impact of new construction on existing assets is a complex task.  It is necessary to understand the geometry of the new and existing assets, proposed construction methodology, material properties for the assets and the surrounding soil, carbon impact and the condition of the existing assets.

Simplified assessment methods exist but by their very nature these are inherently conservative, and asset owners are inevitably cautious; a better understanding of the mechanisms involved would potentially allow this level of conservatism to be reduced. The vision of this Consortium is to conduct research, informed by practice, which will further our understanding and engineering capabilities in this important area.

News and events

• CoRCUS meeting 1(a) – 27^th January, 2021
• CoRCUS meeting 1(b) – 27^th September, 2021
• CoRCUS meeting 2 – 24^th March, 2022
• CoRCUS meeting 3 – 17^th January, 2023
• CoRCUS meeting 4 – 29^th June, 2023
• CoRCUS meeting 5 – 20^th September, 2023
• CoRCUS meeting 6 –  5^th March, 2024
• CoRCUS meeting 7  – 28^th November, 2024
• CoRCUS meeting 8 – 2^nd June, 2025
• CoRCUS meeting 9 (CoRCUS x GENIUS) – 19^th November, 2025
• CoRCUS meeting 10 –  28^th April, 2026

Funding and support from:

Consortium partners

• Dr Sam Divall – Chair

Sam is a Senior Lecturer in Geotechnical Engineering at City St George’s, University of London. Dr Divall has published papers mostly on the ground's response to underground construction in congested underground space. Dr Divall has worked on many collaborative research projects involving both numerical and physical modelling often with international researchers. He is a Chartered Civil Engineer with the Institution of Civil Engineers (ICE). He is also an invited member of the ISSMGE Technical Committee for Physical Modelling in Geotechnics (TC104) and a Fellow of the Higher Education Academy. He was Vice-chair or the organising committee for the 9th International Conference on Physical Modelling in Geotechnics (ICPMG 2018) and co-editor of the proceedings. Dr Divall won the British Geotechnical Association’s Young Geotechnical Engineers’ Symposium Award (2012) and has been an invited speaker at many international conferences. Currently, Dr Divall is Chair of the Consortium for Research into Congested Underground Space (CoRCUS), Director of the Civil Engineering Laboratory and Giant shear box facility and Director of the Research Group into Transforming Urban Environments (TrUE). He is PI on R&D funded projects for HS2 and his research outputs include 14 journal articles, 32 international conference papers, co-editor of one international
conference proceedings and a pending patent. He has supervised two PhD candidates to completion
and is currently first supervisor to another three PhD candidates.

• Dr Neil Philips – Vice-chair (COWI)

Neil is a Principal Tunnel Engineer at COWI with 18 years’ experience within the tunnelling and underground space sector. He has worked on many projects ranging from the construction of shafts and pipe jacks, up to large infrastructure tunnelling works. He obtained a Master’s degree and PhD investigating the understanding and optimisation of slurry tunnelling; which were sponsored by the tunnelling industry. He currently sites on the British Tunnelling Societies Net Zero Tunnelling group committee as a founding member, along with being vice-Chair of the Consortium for Research into Congested Underground Space (CoRCUS). He is also a Chartered Civil Engineer with the Institution of Civil Engineers (ICE). Neil is currently an Honorary Lecturer at City St Georges University, advising on industry best practice in the underground world, previously lectured on the Temporary Works Masters course at City St George’s, University of London.

Academic Partners

• Prof Michael CR Davies (City St George's, University of London)
• Prof Sarah Stallebrass (City St George's, University of London)
• Prof Neil Taylor (City St George's, University of London)
• Dr Miguel Bravo Haro (City St George's, University of London)
• Dr Binh Le (City St George's, University of London)
• Prof Jamie Standing (Imperial College)
• Prof Emilio Bilotta (University of Napoli Federico II, Italy)

Industry Partners

• Paul Gallagher - Managing Director Designate (Joseph Gallagher Limited)
• Hilary Skinner - Technical Director (COWI)
• Dr Vicky Potts - Technical Director (COWI)
• Jag Chima - Technical Director (COWI)
• Paul Challinor - Senior Construction Manager (STRABAG)
• Dr Richard Goodey - (Buro Happold)
• Mo Gajia - Lead Project Engineer (Bakerloo Line Extension at TfL)
• Dr Njemile Faustin – Principal Geotechnical Engineer (AECOM)
• Anita Wu - Tunnel Engineering Manager (SCS Railways)
• Dr Eric Ritchie - Innovation Manager (Ferrovial)
• Dr Chris Menkiti - Senior Partner (Geotechnical Consulting Group LLP)
• Ross Dimmock - Vice President Tunnelling (Normet Group)
• Martyn Noak - Head of Ground Engineering & Tunnels (HS2 Ltd)
• Mark Lemmon - Lead Tunnelling Engineer (HS2 Ltd)
• Naomi Wheeler Reed  - Associate Director (OTB Engineering Ltd)

Current projects

CoRCUS P1: Reducing the risk of long-term damage to buildings caused by tunnelling-induced settlement in soils in low lying South East Asian cities (successfully completed). Supported by: UKRI - Global Challenges Research Fund

Description: The project permitted experts in tunnelling in urban environment at City, University of London to establish collaborative work with engineers and academics in Vietnam, directly, towards the specific issue of tunnelling in the typical soils found in this developing nation. The two teams will work together as co-creators of this research in order to solve problems commonly encountered in South East Asia where many large cities are located in areas that are geologically similar to Ho Chi Minh City. In addition, knowledge transfer of the outcomes of research leading to a greater understating of the engineering challenges associated with tunnelling in challenging ground conditions will enhance the opportunity for UK based engineering consultants to engage in projects overseas, thus enhancing UK invisible exports.

Outputs:  Le et al. (2023)

CoRCUS P2: Quantifying long-term tunnelling-induced ground movements in fine-grained soils (on-going).  Supported by: UKRI - Global Challenges Research Fund

Description: Tunnel construction inevitably leads to ground movements that potentially can damage surface and subsurface structures. It is therefore important, when designing tunnels in urban environments, that the resulting ground response is predicted reliably. Short-term ground movements are directly attributed to the excavation and can be predicted reliably with confidence. However, there is a dearth of guidance on predicting the magnitude and extent of long-term tunnelling-induced ground movements. This works aims to establish the fundamental mechanisms associated with long-term tunnelling-induced ground response, utilising geotechnical centrifuge experiments that simulate the whole-life behaviour of a prototype lined tunnel constructed in fine grained soils.

Outputs: Divall et al. (2022)

CoRCUS P3: An investigation into underground openings from shafts to tunnels (on-going PhD).  Supported by: COWI and Joseph Gallagher Limited.

PhD candidate: Mayda Ucur

Description: During tunnelling works there is the requirement for a connection to other buried infrastructure (e.g. vent shaft or pedestrian tunnel). The operation of connecting the tunnel requires the formation of an opening, the partial demolition of the shaft, disturbing the loading and support equilibrium, and risking the integrity of the structure. This leads to the requirement for temporary works, which are typically omitted from the Permanent Works Designer’s scope, often falling to the Tunnelling Contractor as a temporary works item. Consideration must be given on how ground loads carried by the shaft are transmitted around the newly formed opening. However, this leads to conservative solutions being adopted. There are limited guidance on approaches to the design of an opening in a shaft and result in methods such as wished in place being used. Initially, a comprehensive review of current practice (including an industrial partners sharing method statements).

Outputs : Ucur et al. (2026); Ucur et  al. (2024)

CoRCUS P4: Reducing tunnel volume loss using data processing techniques (on-going PhD). Supported by: Skanska Costain STRABAG Joint Venture on HS2

PhD candidate: Reshuni Limbu

The project will be, firstly, collating two Big Data sets captured during tunnelling works (settlement and TBM driving data) and conducting a series of interrogations to establish the most important variables. The next stage is to employ data processing techniques to create the relationships necessary to predict settlements for a given TBM data set. The aim for this section of the proposed work will be to predict settlement data further along a route using TBM data from earlier in the drive.  The validation of the modelling will be extended by a series of experiments with carefully controlled conditions which will in turn supply more data for the predictive model. The data will be made available if requested for alternative analyses to be conducted by HS2 or its nominated suppliers. The model and all of the HS2 tunnelling data will be not only shared with HS2 and its nominated suppliers, but it will also be wholly non-proprietary and published as part of the academic record and learning legacy of this project.

Civil Engineering Laboratory

Purpose-built laboratory housing a recently refurbished Acutronic 661, 40 g-tonne, geotechnical centrifuge with state of the art instrumentation, image capture, and hydraulic, electrical and optical slip rings.

The centrifuge facility is operated by a highly experienced team of researchers using actuators, motors and syringe pumps to carefully simulate geotechnical events in flight. It is accompanied by space for model preparation, including consolidation presses to create clay soil beds for testing and additional loading frames for 1g testing.

Element testing laboratory containing automated stress path triaxial apparatus, shear box apparatus, a Bishop ring shear apparatus and a high pressure triaxial cell. This facility also provides space for classification tests and a range of customised tests investigating soil slurries, bentonite and the effect of adding polymer.

GENIUS (Geotechnical European Network for Inclusive Underground Spaces)

Project Partners

• Prof Emilio Bilotta (University of Naples Federico II) - Lead
• Dr Sam Divall (City St George's) - Co-lead
• Dr Enrico Soranzo (Boku University)
• Dr Andrea Franza (Aarhus University)
• Dr Alessandra Di Mariano (Universitat Politècnica de Catalunya)
• Dr Luc Thorel & Dr Alain Le kouby (Université Gustave Eiffel)
• Prof Michael CR Davies (City St George's)
• Prof Sarah Stallebrass (City St George's)
• Prof Neil Taylor (City St George's)

Project Descriptor

The purpose of GENIUS is to establish a doctoral network to address the important issue around Inclusive Underground Spaces using novel geotechnical engineering techniques.  This will address specific technical and non-technical challenges including skills gaps in this important area directly related to the climate emergency and the UN Sustainability Development Goals.

Recent Events

On 19 November 2025, a joint CoRCUS × GENIUS event was held, during which network members presented their research to the consortium. As a record of this successful event, the presentations and links to published works are provided below.

• Prof Bilotta's Presentation link
• Dr Soranzo's Presentation link
• Dr Franza Presentation link
• Dr Di Mariano & Dr Pinyol's Presentation link
• Dr Le Kouby's Presentation Link