Study on high pressure shearing test on contact surfaces of coal based paleo-weathered sand-soil rock strata

In order to study the interaction between the soil and rock of the coal based paleo- weathered sand- soil rock strata contract surfaces under the influenc e of the mining interference, a high pressure ( 6 ~ 10MPa) shearing test was conducted on the interaction of the sandy soil- weathered rock contact surfaces. A T- γ curv e of the sandy soil- weathered rock contact surfaces under the high stress was obtained from the test. The test showed that the shearing process under the high stressI evel would have obvious stages and they would be an inter- occlusion stage of the soil- rock and an interaction stage individually. The conversion of the two stages wou Id relate to the crushing of the soil particle material and the rock material, the particle startup- material crushing T- y curve inclined rate reduced would have a consisten cy corresponding relationship and the material crushing effect would have a closed related to the strain hardening or softening features of the T- γ curve. According to th e sectional features of the T- y curve, the initial shearing strength rini and the final shearing strength Tult would be more favorable to explain the shearing features of the sandy soil- weathered rock contact surfaces. The fluctuation features of the contact surfaces were explained with the fractal dimension. The paper analyzed the materia l crushing effect and the relativity and response law on the fluctuation features of the sandy soil- weathered rock contact surface.