A sieve stack separates gravel, sand and fines beside a liquid-limit cup, plastic-limit rolling plate and sample scale. The decision sequence combines fines fraction, coarse-fraction composition, gradation coefficients and inorganic plasticity.
• 3D scene parts: No. 4 / No. 200 sieve stack; liquid-limit cup and cam; plastic-limit rolling plate; sample mass balance station; plasticity chart recorder. • Controls: Passing No. 200 (0–90 %); Sand share of coarse fraction (10–90 %); Liquid limit (20–90 %); Plastic limit (10–40 %); Coarse gradation Cu (2–12); Coarse gradation Cc (0.5–2). • Live readouts: Fines mass fraction (%); Sand mass fraction (%); Gravel mass fraction (%); Plasticity index (%); A-line PI at selected LL (%); Inorganic group symbol. • Guided experiments: Clean well-graded sand; High-plasticity clay; Silt-like fines. • Four tabs (visual laboratory, curves and measurements, experiments, learn and assess), a model-verification run, a timestamped event log and a trial report.
PI=LL−PL; A-line PI=0.73(LL−20) Fines≥50%: inorganic fine-grained group Coarse majority: S if sand≥50% of coarse fraction, else G Clean gradation: Cu≥6 for S or ≥4 for G; 1≤Cc≤3 Fines<5% clean; 5–12% dual; >12% fines-controlled
Teaching subset of inorganic USCS using supplied sieve percentages and index values; not ASTM-certified testing. Includes CL-ML plasticity-border region and clean/dual/fines-controlled coarse groups. Organic soils, peat, unusual borderline symbols and full grain-size curve measurement are omitted. Cu/Cc refer to supplied coarse gradation; a compatible measured sample must establish them in practice. Cup motion and rolling are illustrative. Try the preset experiments, then compare the live readouts with the equations.
Yes. Plasticity index is the water-content interval between those limits.
No. The controls supply test values; the animation explains the equipment.
Teaching subset of inorganic USCS using supplied sieve percentages and index values; not ASTM-certified testing. Includes CL-ML plasticity-border region and clean/dual/fines-controlled coarse groups. Organic soils, peat, unusual borderline symbols and full grain-size curve measurement are omitted. Cu/Cc refer to supplied coarse gradation; a compatible measured sample must establish them in practice. Cup motion and rolling are illustrative.