A six-story residential block near King's Cross hit a snag when early foundation assumptions underestimated the stiff clay's settlement under load. That's where a proper bearing capacity analysis becomes essential. In London, the infamous London Clay sequence can vary laterally within meters, so relying on textbook values alone risks differential movement. We combine In-Situ with lab data to deliver a site-specific allowable bearing pressure that respects both the geotechnical context and the structural demands of your project. Before pouring concrete, it pays to verify assumptions with a targeted plate load test right on the excavation base.
London Clay's stiffness profile can shift by an order of magnitude within a single site, making site-specific bearing capacity analysis non-negotiable for safe foundation design.
Scope of work
Area-specific notes
London's urban expansion over the last century created a patchwork of made ground, old foundations, and buried services atop the natural clay. A bearing capacity analysis that ignores these heterogeneities invites uneven settlement and structural distress. The historic infill of gravel pits and basement excavations adds further complexity. We flag areas where the clay's overconsolidation ratio drops near old river channels, requiring deeper or wider footings. Factoring in the site's anthropogenic history keeps your foundation design grounded in reality, not textbook averages.
Standards used
BS EN 1997-1:2004 (Eurocode 7 – Geotechnical design), BS 5930:2015 (Code of practice for ground investigations), Ciria C641 (Bearing capacity of shallow foundations on clay)
Linked services
Shallow Foundation Capacity
We calculate allowable bearing pressure for pad, strip, and raft foundations using site-specific shear strength parameters from triaxial and vane shear tests. Includes checks against punching, local, and general shear failure modes.
Deep Foundation Capacity
For piles and caissons, we assess end-bearing and shaft friction components using effective stress analysis. Integrates with SPT N-values and CPT cone resistance to refine capacity estimates for London Clay and Thanet Sand layers.
Settlement & Serviceability Check
We estimate immediate, consolidation, and creep settlements under working loads. Combines oedometer moduli with finite element modeling to ensure total and differential settlements stay within structural tolerances.
Typical parameters
Q&A
How is bearing capacity analysis different from a standard soil report?
A standard soil report describes soil types and basic properties, while bearing capacity analysis focuses specifically on calculating the maximum load per unit area the ground can carry without failure. It uses site-specific shear strength parameters, applies partial factors per Eurocode 7, and checks both ultimate limit state (collapse) and serviceability limit state (settlement). In London, where clay stiffness varies widely, this targeted analysis prevents both under-design and over-design of foundations.
What soil tests are used for bearing capacity analysis in London?
We typically rely on consolidated-drained or unconsolidated-undrained triaxial tests on undisturbed samples to get effective cohesion and friction angle. Vane shear tests provide quick undrained strength profiles in clay. For modulus values, oedometer tests on high-quality rotary-cored samples are standard. The combination gives the parameters needed for bearing capacity equations and settlement checks under Eurocode 7.
How much does a bearing capacity analysis cost in London?
A typical bearing capacity analysis for a medium-sized residential project in London ranges from £500 to £1,300. This covers field sampling, lab testing, and the engineering report with calculated allowable bearing pressures and settlement estimates. Larger or more complex sites with deep foundations or variable ground conditions may fall at the higher end. We provide a fixed quote after reviewing the site's scope and access.