EXPERIMENTAL STUDY ON STRENGTH AND CRUSHING BEHAVIOR OF COARSE-GRAINED SOIL

A series of direct shear tests on coarse-grained soil were performed by large multi-function interface shear apparatus.Two sets of comparative shear tests on special sample with particle diameters of 20~50 mm and 10~20 mm were also performed.Then, the mechanical behaviors and strength parameters of coarse-grained soil were analyzed.After the tests were over, all the samples were sieved, and the particle crushing laws were concluded.The results showed that the coarse-grained soil in shearing tests was a hardening material.The non-linear behaviors in strength and sham cohesions in bad gradation samples were observed.However, there were few changes in frictional strength.The sieving results showed that crushing rates increased obviously with the increasing normal stresses.There were hyperbolic connections between crushing rates and normal stresses.Their fitting parameters were closely related to gradations and particle sizes of the samples.