LABORATORY TESTS ON WATER-SATURATED RHEOLOGICAL PROPERTY OF CARBONACEOUS ARGILLACEOUS LIMESTONE

The water-saturated direct shear rock rheological test is carried out on the carbonaceous argillaceous limestone at the slip zone of Jiweishan landslide, Wulong, Chongqing. A rock direct shear rheometer is used. The rheological test results give the shear stress-shear displacement time-history curves of the slip zone and the long-term strength parameters of the rock. The results show that: the long-term strength in the water-saturated conditions significantly decreases, comparing to the rheological strength in the natural conditions and the instantaneous shear strength parameters. The internal frictional coefficient of the carbonaceous argillaceous limestone in the water-saturated conditions is lower than that of natural rheology 13.87%, and lower than that of the instantaneous shear 40.91%. The cohesion of the carbonaceous argillaceous limestone in the water-saturated conditions is lower than that of natural rheology 13.81%, and lower than that of the instantaneous shear 36.67%. Because of the crack damage propagation, the long-term shear strength in the water-saturated conditions decreases, comparing to that in the natural conditions, but does not decrease significantly, comparing to the long-term shear strength of the direct shear rheological test and the instantaneous shear strength. These findings can provide the important experimental and theoretical basis for in-depth understanding and analysis of the rheological mechanical properties of the slip zone soft rock in Jiweishan landslide.