ESTIMATION OF IN-SITU LATERAL STRESSES IN SOILS BY CONE-PENETRATION TEST

A simple method for the estimation of in situ lateral stress in soils using the results of a cone-penetration test (CPT) is described and il lustrated. The method is based on the dependence of cone-penetration-t est sleeve friction on lateral stress. It recognizes that insertion of the cone causes soil disturbance, so the normal stress on the frictio n sleeve must differ from the initial in situ value. The lateral earth pressure on the sleeve during penetration is assumed equal to the Ran kine passive pressure value. Field test results show that the method g ives estimates of lateral stress that compare well with values determi ned by other procedures, such as the self-boring pressuremeter, the fl at-plate dilatometer, laboratory tests on undisturbed samples, and the Brooker and Ireland correlations. The method in its present form requ ires separate assumption or determination of the overconsolidation rat io of the soil.