ISKRIT / Site investigation & geotechnics / Soil index properties · USCS
Site investigation & geotechnics
Soil index properties and USCS classification (ASTM D2487)
From water content, density, and Atterberg limits the tool computes the derived index properties and places a fine-grained soil on the plasticity chart.
Data current as of 2026-09-26
Standards
ASTM D2487 (USCS): the A-line PI = 0.73 (LL − 20) separates clays from silts, LL = 50 separates low from high plasticity, and the hatched band PI 4 to 7 gives CL-ML. Consistency follows the liquidity index.
Input
ρ, ρs, W, WL, WP per sample.
Output
Derived properties, group symbol, consistency.
What it does
- Derived index properties, soil name and variety
- Export the schedule to XLSX and print
- 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
What determines the group symbol?
The position on the ASTM D2487 plasticity chart: above the A-line the soil is a clay, CL or CH; below it a silt, ML or MH; the hatched band with PI from 4 to 7 gives CL-ML.
Where does the consistency come from?
From the liquidity index IL = (W − WP)/IP.