HS2 Wendover ‘green tunnel’: staged excavation and backfill lessons for engineers
Reviewed by Joe Ashwell
First reported on New Civil Engineer
30 Second Briefing
Completion of the central section of HS2’s Wendover ‘green’ cut-and-cover tunnel by the EKFB joint venture (Eiffage, Kier, Ferrovial Construction and Bam Nuttall) marks a key milestone on the Buckinghamshire alignment. The structure is designed to be buried and landscaped to blend with the Chilterns setting, reducing visual and noise impact compared with a surface alignment. For designers and contractors, the works involve complex staged excavation, temporary works and waterproofing to allow subsequent backfilling and load transfer from the restored ground profile above.
Technical Brief
- Precast concrete tunnel elements allow rapid installation windows and minimise open excavation exposure durations.
- Segmental construction facilitates staged backfilling and progressive load transfer onto the tunnel roof slab.
- Cut-and-cover methodology demands continuous groundwater and surface-water management to protect the waterproofing envelope.
- Construction sequencing must maintain rail alignment tolerances while accommodating settlement of reinstated overburden.
Our Take
EKFB’s completion of the River Great Ouse viaduct, reported on 2 October 2026, shows the same joint venture team (Eiffage, Kier, Ferrovial Construction and Bam Nuttall) is now delivering multiple complex HS2 structures in sequence, which typically improves programme certainty and interface management along this Buckinghamshire stretch.
Kier’s recent revenue and profit growth, alongside its place on Pagabo’s £4.29bn National Framework, suggests the Wendover ‘green’ cut-and-cover tunnel forms part of a broader pivot towards large, framework-backed UK infrastructure work rather than one-off major projects.
Within our 899 Infrastructure stories, HS2-linked items featuring EKFB stand out for combining earthworks-heavy assets like cut-and-cover tunnels with elevated structures such as viaducts, indicating the JV is building a strong reference portfolio in multi-modal linear infrastructure that will be relevant for future UK rail and highway bids.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
Related Articles
Related Industries & Products
Construction
Quality control software for construction companies with material testing, batch tracking, and compliance management.
Mining
Geotechnical software solutions for mining operations including CMRR analysis, hydrogeological testing, and data management.
QCDB-io
Comprehensive quality control database for manufacturing, tunnelling, and civil construction with UCS testing, PSD analysis, and grout mix design management.