SHEAR STRENGTH OF COMPACTED COHESIVE SOILS

Abstract

anisotropic shear strength characteristics-of • a "compacted soil has been' investigated. Compacted soil samples at various inclinations were extracted' from a specially fab.. ricated mould of 4" diameter and 8" height. A 2h wide slit was cut in the mould throughout its length. Through this slit,' the soil samples could be extracted. The samples were compac-ted .on the wet side of optimum so as to produce dispersed structure thereby inducing anisotropy. Consolidated undrained tests were conducted on various samples extracted from the above mentioned mould at various inclinations with the hori-zontal 0( = 0°, 30°, 60° and 90°. The effective stress parameters were found to be maximurr for vertical and minimum for samples inclined at an angle c( = 30°. Unconfined compression tests also showed the maximum strength in case of vertical and minimum at ct = 30°. This behaviour was further substantiated by the fact that highest po....1-e pressure developed in the soil sample yielding the minimum strength. It was suL7prising to note the above referred anisotropic behaviour of compacted soil in constrast to that observed in case of anisotropically consolidated soils exhibiting least strength, C' and 0' in lateral direction = 0°.