Live module

Geotechnical Analysis Calculator

Safe bearing capacity from SPT N-values, liquefaction screening and soil classification — IS 6403, Terzaghi, Meyerhof and Bowles.

Estimate safe bearing capacity from a borehole log in minutes. Apply N-value corrections (overburden, rod-length, hammer energy), compute SBC by four methods, and screen for liquefaction per IS 1893 and the NCEER simplified procedure.

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Design codes
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Use cases
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FAQs answered

Design codes supported

IS 6403:1981
Indian code for safe bearing capacity of shallow foundations
IS 1893 (Part 1):2016
Seismic design — liquefaction susceptibility
Terzaghi (1943)
Classical bearing capacity equation
Meyerhof (1956)
SPT-N to SBC correlations
Bowles (1996)
Modern SPT-based bearing capacity correlation
Why engineers pick it

What makes this different

Four methods, one borehole

See SBC from IS 6403, Terzaghi, Meyerhof and Bowles in the same chart — judge engineering scatter at a glance.

NCEER liquefaction screening

Cyclic stress ratio vs cyclic resistance ratio for every layer — flagged red where FS < 1.0.

Multi-layer soil model

Up to 20 soil layers per borehole with independent unit weight, water table and SPT corrections per layer.

Designed for foundation handoff

The SBC profile exports straight into the Foundation Design module — no copy-paste between tools.

Workflow

How it works

  1. 1

    Enter borehole log

    Layer thickness, soil type, SPT N-values and water-table depth.

  2. 2

    Apply corrections

    Overburden (CN), rod length (CR), hammer energy (CE) and borehole diameter (CB) — toggle individually.

  3. 3

    Compute SBC by method

    IS 6403, Terzaghi, Meyerhof and Bowles — settlement-controlled and shear-controlled SBC reported separately.

  4. 4

    Screen for liquefaction

    CSR vs CRR per layer with peak ground acceleration; layers below FS = 1.0 are flagged in red.

Real-world use

Common scenarios

Pre-design ground report review

Sanity-check a soil consultant's SBC by running the same N-values through four methods.

High-seismic zone screening

Cities in seismic zones IV and V — liquefaction screening informs whether ground improvement is needed.

Loose sand site

Where N < 10, SBC is settlement-controlled — Bowles vs Meyerhof gives different answers; the tool surfaces both.

Quick proposal pricing

Estimate SBC quickly to decide pad vs raft vs pile before full geotechnical investigation.

Worked examples

Try it on a real scenario

Three engineering cases with the inputs and expected results. Open one to see exactly what to type into the calculator.

Questions

Frequently asked questions

Overburden (CN), rod length (CR), hammer energy (CE) and borehole diameter (CB). Each can be toggled if the field log has already corrected for them.
Yes — NCEER simplified procedure with CSR / CRR by layer, plus IS 1893 susceptibility checks. PGA can be entered manually or pulled from seismic zone.
For most Indian projects, IS 6403 governs. The other three are shown for engineering judgement — wide scatter usually means more investigation is needed.
Yes. Up to 20 layers with independent properties; the tool computes a settlement-weighted average SBC at the chosen footing depth.
Yes — the SBC profile flows directly into the Foundation Design module so design depth and bearing pressure stay consistent.

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