← GHRM manual

Railway Ground Hazard Risk Management · Reference

Empirical Equations & Correlations

In-situ test, index-property, rock-mass/rockfall and landslide/debris-flow correlations, each with its original source and the constraints on its use. Search by parameter, symbol, author or material; filter by family.

Use limitations. Every equation here is a statistical fit to a specific data set. Use only within the stated materials and ranges, prefer site-specific calibration, and confirm coefficients against the cited original before relying on them for design. Units are as published; Pa = atmospheric pressure (≈101.3 kPa, 1.06 tsf).

Note required when an equation is used. Wherever a correlated value is reported — a calculation, boring log, design-parameter table, report or GHRM assessment — record with it:
  1. the equation ID and source (e.g. IS-02, Liao & Whitman 1986);
  2. that the soil or rock is within the equation’s range of applicability;
  3. that the value is correlated, not tested;
  4. the governing limitation, and the test that will confirm the value.

References