Programme

The Fifty Fenchurch Street development, situated in the City of London, combines the delivery of a 36-storey commercial office tower with the preservation of Grade I-listed heritage assets. The scheme required the adoption of highly complex basement engineering solutions within a constrained urban and historically sensitive setting.

At the core of the project is a four-storey basement, constructed using a secant piled wall in conjunction with a three-tier propping system. This arrangement provided excavation stability while simultaneously addressing the dual imperatives of permanent works integration and heritage preservation.

A key challenge was the presence of the 700-year-old medieval Tower of All Hallows Staining within the site. Excavation support for this structure was achieved through the installation of a new permanent foundation, linked to a temporary ring beam supported by plunge columns. Hydraulic jacking mechanisms were incorporated into the design to mitigate and control settlement, thereby safeguarding the integrity of the historic asset.

This session will examine the geotechnical challenges encountered, the temporary works strategies implemented, and the underpinning sequence devised to protect existing assets. It will also highlight the collaborative design methodologies adopted, illustrating how multidisciplinary coordination facilitated the safe and successful delivery of basement works in one of London’s most constrained and historically significant contexts.

This session explores the geotechnical, hydrogeological, and geoenvironmental ground investigations underpinning feasibility studies for the proposed Future Circular Collider (FCC) at CERN,  a next-generation particle accelerator three times the size of the LHC. Structural Soils, working as part of an international consortium, led detailed site investigations in Haute-Savoie, France, to de-risk future tunnelling and underground construction. 

Delegates will gain insight into: 

• Geological complexity, including high water-bearing Quaternary deposits, Molasse formations, and karstic limestones. 
• Managing construction risks such as high groundwater pressures, ground gas, and challenging winter site conditions. 
• A multidisciplinary collaboration model, integrating drilling, geophysics, monitoring, HSE, and logistics across multiple RSK Group businesses and European partners. 
• Development of realistic geological models to inform tunnel alignment, future site investigations, and European strategy updates. 

This landmark project highlights how complex international investigations can both advance ground engineering practice and support cutting-edge scientific infrastructure. 

Engineers have completed a programme of deep ground and riverbed investigations at the Palace of Westminster to support the forthcoming Restoration and Renewal works. Between April and September 2025, 16 boreholes were drilled on the river terrace and in the Thames to depths of up to 74.5m, alongside installation of groundwater, vibration and water-quality monitoring equipment. The surveys will inform designs for basements, services and temporary river works, while protecting the Grade I listed structure. The investigations also uncovered 19th-century timber piles linked to the Palace’s original construction, and coincided with the appointment of contractors to a new £1.5bn Parliamentary Construction Partnership framework.

The complexity of today's basement projects is increasing the need for value engineering and selecting solutions that balance structural demands with practical buildability, as well as how to balance more sustainable methods with bespoke capabilities.

When is the right time for geotechnical, piling and temporary works contractors to be involved in the bid and planning phases of a major basement project? The panel will discuss this in relation to how to improve buildability and adhere to commercial goals. 

Project build programmes are becoming more condensed and clients want projects delivered faster for less.

The panel will discuss how contractors on the project achieve the best temporary works design, sequencing and installation plans, to deliver a more efficient and safer project. The audience will also be invited to ask questions and share their experiences. 

Gillian Dick will present Glasgow’s Environmental Digital Twin, a 2D and 3D representation of the city’s natural assets that integrates environmental and spatial data to inform planning, resilience, and sustainable development. Holger Kessler will give an overview of the lessons learnt from the National Underground Asset Register Programme and what future subsurface use cases might be addressed following the latest announcements by DSIT and the Ordnance Survey Andrea Gillarduzzi will talk about the  Digital Transformation of Ground Data initiative that envisages a future where ground data is seamlessly connected, transparently shared, and intelligently interpreted across the entire infrastructure lifecycle. DTGD' goal is to foster a collaborative, interoperable, and digitally mature ecosystem that empowers all stakeholders with timely, reliable, and context-rich subsurface data and information.

This follow-up to the 2024 event’s, highly regarded session returns to the pioneering full-scale piled raft monitoring programme underway at Edge London Bridge, now with over two years of data from a complex mixed-use site. In 2024–2025, the project reached new technical milestones in validating design assumptions against measured soil-structure interaction during excavation and loading. The presentation will unpack how the observed performance of individual piles and the connecting raft compared to both finite element and empirical design predictions, what instrumentation drift was detected and corrected, and how this feedback loop is now actively influencing foundation optimisation on new basements across the UK. 

This session will dissect the impact of the Building Safety Act (BSA) on deep basement and subterranean projects, focusing on how the legislation is reshaping responsibilities, design practices, and project delivery timelines. 

The panel will cover: 

• The shift in accountability to defined duty-holders 
• Structural competency requirements for below-ground works 
• The integration of digital record-keeping (“the golden thread”) for underground safety and compliance 

A pre-event survey of industry professionals will inform the discussion, allowing the panel to address the most pressing questions and concerns from practitioners. Expect a frank and honest conversation about the real-world implications of the Act. 

The panel will also explore how early design requirements, while perceived by many as slowing the sector, can be leveraged to drive better outcomes and how consultants and contractors can adapt to this new landscape.

At the heart of New York’s Times Square, the TSX Broadway project redefined what is possible in urban engineering. The scheme combined selective demolition of a 47-storey tower, excavation of anew 4.6m below-grade retail level, and the unprecedented raising of the 109-year-old Palace Theatre by 9.5m, all within one of the busiest intersections in the world. 

This session will explore how Langan’s integrated approach to investigation, design, and construction support enabled delivery of a one-of-a-kind building while safeguarding adjacent structures and subway tunnels. 

Key themes include: 

• Balancing heritage and innovation: preserving and lifting a landmark theatre while creating new retail and hotel space 
• Complex below-grade works in constrained sites: excavation support, caisson design, and stability of surrounding buildings 
• Sustainability in practice: minimising waste and CO₂ emissions through selective demolition and embedded foundation solutions 
• Collaboration as a driver of success: coordinating across agencies, contractors, and disciplines to meet cost and schedule goals 

The project showcases how innovative geotechnical engineering can transform the challenges of dense, historic cityscapes into opportunities for landmark redevelopment.

Thousands of piling projects are completed across the UK each year, yet much of the knowledge they generate remains locked within individual organisations. As an industry, this fragmented data landscape limits our ability to learn from past work, improve design efficiency, and unlock the embodied carbon savings associated with more efficient pile design and foundation reuse. The Federation of Piling Specialists (FPS) Digital Progression Group has set out to change this through the creation of the FPS Piling Map – a national, publicly accessible, cloud based GIS platform that signposts past piling project information across the industry. This initiative is not a data harvesting exercise. Instead, it provides a simple, secure mechanism for FPS members to indicate past piling projects, provide optional metadata such as the type of piling, and enables users to request information from the FPS member. By sharing only essential, non commercially sensitive metadata, traditional barriers to data sharing are removed while enabling industry wide visibility of decades of piling expertise. The technical concept is built on established ESRI web GIS technology, selected for its familiarity across the engineering sector, future scalability, and ability to integrate seamlessly with existing FPS digital infrastructure. Data ingestion is streamlined through standardised CSV templates aligned with the FPS quarterly reporting process, supported by automated workflows. This ensures a low effort, repeatable process for members and reduces long term operational costs.

The value of this platform extends far beyond a simple map. For consultants and designers, early access to project locations, pile testing information, and site characteristics can significantly enhance preliminary design, reducing duplication of site investigations and enabling better-informed decisions on foundation reuse and options. For clients and developers in addition to this, improved clarity of historic ground behaviour helps strengthen early contractor engagement and optimise procurement strategies. For society, more efficient design directly contributes to embodied carbon reduction, reduces the duration of piling operation impacts, and reduces plant on the roads – supporting the sector’s broader commitments to sustainability and net-zero delivery. Crucially, the FPS Piling Map creates a foundation for future digital innovation. With the platform already designed to incorporate new layers – geology, open data, working group outputs, and carbon metrics – it provides a flexible environment for future research, tool development, and integration of automated data pipelines. Above all, this project is a demonstration of what collective action within a specialist industry can achieve. By aligning the expertise of piling contractors, consultants, and digital specialists, the FPS has delivered a practical, scalable solution that enhances transparency while protecting intellectual property. It represents an important cultural step towards an industry where subsurface data is shared responsibly, efficiently, and for the collective good of the built environment. The FPS Piling Map is therefore not merely a digital tool, but a collaborative platform with the potential to reshape how we understand and design underground structures across the UK. We believe it aligns strongly with this conference’s ambition to showcase future focused, innovative approaches to subterranean engineering.

Queenstown, New Zealand, is located in a high seismic hazard zone with soils susceptible to liquefaction. As part of the comprehensive redevelopment of a four-story shopping mall in the town center, a seismic upgrade was implemented to achieve 75% of the New Building Standard (NBS). While significant superstructure strengthening was undertaken, the retrofit design also addressed subgrade performance by incorporating ground improvement measures. Resin Injection was employed to mitigate liquefaction risk, forming a 5 m thick non-liquefiable crust beneath the existing foundation system. This was achieved by increasing the equivalent clean sand penetration resistance (qc1Ncs) by approximately 30%.

This paper highlights the effectiveness of Resin Injection for liquefaction mitigation in constrained urban environments and demonstrates how integrating ground improvement into seismic retrofit strategies can enhance structural resilience while providing a cost-efficient solution for underground works.

The paper presents a case study for ground improvement beneath the basement of a four-story shopping mall in Queenstown, New Zealand. Due to the high seismic risk and soft soils, a 5 m thick improvement zone was required beneath the structure to improve its performance as part of a seismic retrofit works package. The effectiveness of this technique in enhancing foundation performance is outlined, demonstrating how integrating ground improvement into retrofit design can deliver a cost-effective solution for structures in constrained urban environments.

 Tim Chapman will open the final session with a short provocation that sets the context for Beneath the Surface, Beyond the Future. Drawing on international comparisons and recent project examples, he will challenge the UK’s approach to delivering underground infrastructure, questioning why schemes take longer and cost more, and what this means for productivity, value and long-term competitiveness. This introduction will frame the panel discussion that follows, prompting debate on how the industry can deliver better outcomes below ground and make investment go further.

This closing panel looks ahead to the future of underground engineering, asking whether tomorrow’s basements will power cities as geothermal energy hubs, safeguard data as critical digital centres, or even host habitable spaces. Drawing on insights shared throughout the day, the panel will explore how climate adaptation, net-zero targets, digital transformation, and urban densification will reshape below-ground design and reuse. From low-carbon materials and advanced monitoring to shifting regulations and funding models, speakers will challenge delegates to reimagine the role of subterranean infrastructure in creating resilient, connected, and sustainable cities.