Geotechnical Engineering

Interactive USCS soil classification tool per ASTM D2487. Input grain size distribution data (% passing No. 4, No. 40, No. 200 sieves) and Atterberg limits (Liquid Limit, Plastic Limit). The classifier computes the Plasticity Index, Coefficient of Uniformity (Cu), and Coefficient of Curvature (Cc), then walks through the USCS decision tree to assign the correct group symbol (GW, GP, GM, GC, SW, SP, SM, SC, ML, CL, MH, CH, OL, OH, Pt) and group name. An interactive plasticity chart plots the soil against the A-line and highlights the classification zone.

Terzaghi-Meyerhof bearing capacity calculator for shallow foundations. Input soil friction angle (phi), cohesion (c), unit weight (gamma), footing depth (Df), footing dimensions (B x L), and load inclination. Computes Nc, Nq, N_gamma bearing capacity factors, applies Meyerhof shape and depth correction factors, calculates ultimate bearing capacity (qu) and allowable bearing capacity (qa) for selected factor of safety (2.5 or 3.0). Separate tabs for undrained (phi=0) and drained analysis.

Simplified Bishop method slope stability analysis for circular failure surfaces. Define slope geometry (height, angle), soil layers (c, phi, gamma), and groundwater table. The simulator searches for the critical failure surface by grid search over center coordinates and radius, computes FS for each candidate surface using Bishop Simplified equations, and displays the critical surface with minimum FS on a cross-section diagram. Seismic coefficient (kh) input for pseudo-static analysis.