Geomechanics.io

  • Free Tools
Sign UpLog In

Geomechanics.io

Geomechanics, Streamlined.

© 2026 Geomechanics.io. All rights reserved.

Geomechanics.io

CMRR-ioGEODB-ioHYDROGEO-ioQCDB-ioFree Tools & CalculatorsBlogLatest Industry News

Industries

MiningConstructionTunnelling

Company

Terms of UsePrivacy PolicyLinkedIn
    Projects
    Safety

    Betws‑y‑Coed bridge foundations: cofferdam design and access lessons for engineers

    March 23, 2026|

    Reviewed by Joe Ashwell

    Betws‑y‑Coed bridge foundations: cofferdam design and access lessons for engineers

    First reported on The Construction Index

    30 Second Briefing

    Foundations are now complete for a new 50‑metre shared-use suspension bridge replacing the historic Sappers’ Bridge over the River Conwy at Betws‑y‑Coed, built under a £3m Conwy County Borough Council contract with MWT Civil Engineering. Deep abutment excavations for mass concrete plinths were formed in a high water table using a sheet‑piled cofferdam with interlocking Larssen piles, welded corners, Groundforce Mega Brace beams and three MP50 hydraulic struts. Two ICE8SG side‑grip hammers installed piles over 6m long, while an unusual sheet‑piled ramp provided plant access without cranes beside the 14th‑century St Michael’s Church.

    Technical Brief

    • Mass concrete plinths at each abutment are designed to resist main suspension cable anchor loads.
    • Live road and protected trees adjacent to the cofferdam constrained plant positioning and excavation footprint.
    • Interlocking Larssen sheet piles with welded corners were specified to minimise water ingress from the high water table.
    • Two ICE8SG side‑grip hammers were selected over standard EMVs to safely handle >6 m piles.
    • Cofferdam support used Groundforce Mega Brace modular beams with three MP50 hydraulic struts spanning excavation walls.
    • An inclined, sheet‑piled access ramp into the excavation removed reliance on cranes for plant access, reducing lifting risk.

    Our Take

    The 2021 safety-driven closure of Sappers’ Bridge fits with a cluster of Safety-tagged UK pieces in our coverage where local authorities, including Conwy County Borough Council, are being forced into accelerated replacement of century-old crossings once inspections reveal latent defects, rather than relying on incremental strengthening.

    Geotechnical Software for Modern Teams

    Centralise site data, logs, and lab results with GEODB-io, CMRR-io, and HYDROGEO-io.

    No credit card required.

    • Save and export unlimited calculations
    • Advanced data visualisation
    • Generate professional PDF reports
    • Cloud storage for all your projects

    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

    Strabag’s Pfaffensteig Tunnel contract: design and delivery notes for rail engineers
    Infrastructure
    about 1 month ago

    Strabag’s Pfaffensteig Tunnel contract: design and delivery notes for rail engineers

    Strabag and Group company Züblin have secured the design-and-build structural works for the ABS Gäubahn Nord/Pfaffensteig Tunnel in south-west Germany, centred on an 11km twin-bore rail tunnel linking Stuttgart Airport station directly to the Gäubahn line towards Switzerland. About 9.8km will be driven by two TBMs, with conventional tunnelling for the A8 motorway undercrossing and airport connection, plus a 240m cut-and-cover section, retaining structures, railway underpasses and a grade-separated crossing. A 3km surface section will be upgraded and partially realigned for 200km/h operation, delivered under an integrated project delivery model with Ed. Züblin, Wayss & Freytag and Strabag AG sharing tunnelling, structural and earthworks packages.

    National Grid TBM under the Thames: tunnelling design and risk notes for engineers
    Infrastructure
    3 months ago

    National Grid TBM under the Thames: tunnelling design and risk notes for engineers

    A 271.5‑tonne Herrenknecht Mixshield TBM, Caroline, has started driving a 2.2km electricity cable tunnel with a 4m internal diameter beneath the River Thames in Essex for National Grid’s Grain to Tilbury project, delivered by the Ferrovial BEMO joint venture. The drive will pass through variable Thames estuary ground conditions between 35m‑deep launch and reception shafts of 15m and 12m diameter, with tunnelling continuing into 2026 and overall scheme completion targeted for 2029. The new tunnel will replace the 1969 Thames Cable Tunnel and carry new high‑voltage circuits between Grain and Tilbury substations.

    Panama Canal Mixshield undercrossing: design and tunnelling lessons for engineers
    Infrastructure
    4 months ago

    Panama Canal Mixshield undercrossing: design and tunnelling lessons for engineers

    A 13.46m diameter Herrenknecht Mixshield TBM has broken through into the future Balboa station on Panama Metro Line 3 after completing the first-ever TBM undercrossing of the Panama Canal at depths exceeding 60m below sea level. The 5,600kW, 26,616kNm machine, fitted with an accessible cutterhead and more than 4,500 sensors linked via the Herrenknecht.Connected platform, has achieved peak advance of 150 segment rings (about 300m) per month through mixed sandstone, tuff, breccias and basalt. Around 1.5km of the 4.5km twin-track tunnel remains to final breakthrough.

    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.

    CMRR-io

    Streamline coal mine roof stability assessments with our cloud-based CMRR software featuring automated calculations, multi-scenario analysis, and collaborative workflows.

    HYDROGEO-io

    Comprehensive hydrogeological testing platform for managing, analysing, and reporting on packer tests, lugeon values, and hydraulic conductivity assessments.

    GEODB-io

    Centralised geotechnical data management solution for storing, accessing, and analysing all your site investigation and material testing data.

    AllGeotechnicalMiningInfrastructureMaterialsHazardsEnvironmentalSoftwarePolicy