Studio 03 — Geo

From field blows to design parameters.

Paste an SPT or CPT sounding and get corrected N-values, a soil classification, cohesion, friction angle, unit weight and bearing capacity. Every result is a published correlation — named and referenced — and the full working lands in the PDF.

SPT + CPT energy, overburden & rig corrections
4 methods Terzaghi · Meyerhof · Hansen · Vesic
Every value cites the correlation it came from
BH-01 — SPT PROFILEDEPTH 0.0 M
0.0 1.5 3.0 4.5 6.0 N₆₀ 9 · soft clay (CL) N₆₀ 14 · firm clay (CL) N₆₀ 22 · med. dense sand (SP) N₆₀ 31 · dense sand · φ′≈34°
DESIGN LAYER — 5.0 M · dense sand
Unit weight γ19.1 kN/m³SPT
Friction angle φ′34° ±15%Wolff · PHT
Cohesion cᵤn/a — coarsegated
(N₁)₆₀ normalised26Cn ≤ 2.0
Allowable bearing185 kPaMeyerhof 1976

How it works

Raw soundings in. Referenced parameters out.

STEP 01

Paste the sounding

Drop in SPT blow counts or CPT tip and sleeve readings by depth, with what you know about the rig — hammer energy ratio, borehole diameter, rod length, sampler liner. Missing fields are handled with stated assumptions, not silent guesses.

STEP 02

Corrections applied in code

Field N is corrected to N₆₀ for energy, borehole, rod and sampler effects, then overburden-normalised to (N₁)₆₀ with Cₙ capped at 2.0. CPT tip resistance is normalised the same way. Deterministic — the same sounding always returns the same numbers.

STEP 03

Classify, then gate

The soil is classified first — driller's description for SPT, Robertson behaviour type for CPT — and only the physically meaningful parameters are exposed: friction angle for coarse soils, cohesion for fine. The other is flagged not-applicable rather than forced.

STEP 04

Bearing capacity on your footing

Enter footing width, length, depth and shape. The engine solves ultimate and allowable bearing by Terzaghi, Meyerhof, Hansen and Vesic, then reports the governing (most conservative) allowable value against your factor of safety.

STEP 05

A PDF that shows its working

Export the log, per-depth results and design summary — every correlation named, every assumption listed, and an uncertainty band on each output. Ask the report questions and the assistant answers only from the computed data.

What's under the hood

Named correlations, not black boxes.

Preliminary, advisory estimates from published empirical correlations — every one traceable to its source.

CORRECTIONS

SPT & CPT

Field readings normalised for the things that actually bias them, before any parameter is derived.

N₆₀ = N·(ER/60)·Cb·Cr·Cs (N₁)₆₀ = N₆₀·Cₙ, Cₙ ≤ 2.0 Skempton 1986 · Youd 2001 Robertson SBT (qc, Rf)
PARAMETERS

Strength & state

Continuous fits kept consistent with the classic descriptive bands, each with an uncertainty range.

φ — Peck/Hanson/Thornburn φ′ — Kulhawy & Mayne (CPT) cᵤ ≈ 6·N₆₀ — Terzaghi & Peck γ — Robertson 2010
BEARING

Four classical methods

Nc, Nq per Reissner/Prandtl; Nγ per each author; shape factors per De Beer/Hansen — governing value reported.

Terzaghi · Meyerhof Hansen · Vesic Footing geometry input Governing q_all at your FS

Free to start · no card required

Turn your next sounding into a design layer.

Paste the field data, set your footing, and read the governing bearing capacity in minutes.