ISKRIT / Site investigation & geotechnics / Grain-size distribution · USCS
Site investigation & geotechnics
Grain size distribution and USCS classification: d10, d60, Cu
From sieve and hydrometer analysis the tool plots the particle size distribution curve, finds the controlling diameters, and classifies sands and coarse-grained soils.
Data current as of 2026-09-26
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Free, no sign-up · interface in Russian
Standards
USCS (ASTM D2487) and EN ISO 14688-1: group symbol from the grain size distribution and plasticity, Cu = d60/d10, Cc = d30²/(d10·d60).
Input
Percent passing or partial masses retained in grams per sieve; computed in the browser.
Output
Curve, d10/d30/d60, Cu, Cc, soil name.
What it does
- Grading curve, d10, d30, d60, Cu, Cc and the soil name
- Load the sieve table from Excel, export to XLSX, print the curve
- Calculations are stored on the server and reopen next time, company letterhead with signatures
Price
Free in full, no sign-up and no payment.
Open the calculator →Questions
Which analyses are supported?
Sieve analysis for sands and coarse soils, hydrometer analysis for fine fractions.
How is uniformity assessed?
Cu = d60/d10; soil with Cu below 3 is classed as uniform.
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