Soils

2 tools in the Civil and Geotechnical area.

Bearing Capacity and Settlement

Shallow foundation design: the ultimate bearing capacity of a strip, square, rectangular or circular footing by the Terzaghi (1943), Meyerhof (1963), Hansen (1970) and Vesić (1973) equations side by side, each with its own N factors and shape, depth and inclination factors as tabulated in USACE EM 1110-1-1905; Meyerhof's effective area for a column load with moments, the middle-third check, the water table by the EM 1110-1-1905 or FHWA GEC 6 rule; the allowable pressure q_u / FS with the code factor named and the applied pressure checked against it as a plain requirement. Settlement: the immediate settlement by the elastic influence factors (USACE EM 1110-1-1904 Table 3-3a, Steinbrenner's layer factors) or by Schmertmann's strain-influence method, and the primary consolidation of a clay layer with the stress increase by the 2:1 or Boussinesq distribution, both against the allowable settlement. The default is a 2 m square footing 1.5 m deep in a c-φ soil (c 10 kPa, φ 30°, 18 kN/m³) under 1,000 kN, SI units.

1 worked example reproduced, listed on the tool page.

Slope Stability

Limit-equilibrium stability of a slope drawn as a ground-surface polyline over up to five soil layers with a piezometric line, a surcharge, a horizontal seismic coefficient and a tension crack. For a specified circle and for the critical circle of a centre-grid and tangent-elevation search the factor of safety is computed by the Ordinary Method of Slices, the Simplified Bishop, the Simplified Janbu (with Janbu's correction) and Spencer's methods as written in USACE EM 1110-2-1902 Appendix C, with the slice table of the critical circle, the ten lowest circles, a drawing of the slope and the F field, and the iteration history; a non-circular surface is analysed by Janbu and Spencer; an infinite-slope closed form covers shallow sliding. The default is the end-of-construction embankment of EM 1110-2-1902 Figure F-10 (3:1 and 2.5:1 faces, two undrained soils, circle at (101, 259) ft of radius 278 ft, F = 1.33 by the manual's Bishop hand calculation).

1 worked example reproduced, listed on the tool page.

Other Civil and Geotechnical sections

Design Loads · Steel Design · Concrete Design · Foundations · Timber and Masonry · Hydraulics · Surveying and Earthwork