Soft Rock Deformation Mechanism Of Destruction Out Horizontally Layered Slope

Fluid is regarded as a isotropous object which can produce continuous transformation under the influence of external force. The difference between fluid and solid is mobility or deformability. Generally speaking, soft rock is a heterogeneous system whic made up by solid phase, liquid phase and gas phase. The same as fluid, soft rock also has the property of runny, especially the low stress soft rock which was influenced by water.Because rock mass experienced times of transformation by tectonic movement and supergene evolution by external agent secondary role, there were many kinds of joints in the rock mass.To slopes with flat-bedded hard and soft rock layers, the rheology of soft rock may lead tensile stress. Because the strength of extension of rock is very low, it means that the vertical joint in the hard rock certainly will be stretched. This kind of stretching will be enough to make the surface of the slope be destroyed with the cooperation of water pressure.Using for reference of the theory and methods, this paper researched the influence of hard rock by the rheology of soft rock, explored the action of in-coalescence in the hard rock under the influence from this force. Based on the result of theoretical research, this paper proceeded laboratory test and numerical simulations. The results of three kinds of research supported mutually, meant the research got a good consequence.The failure mechanism of slopes with flat-bedded hard and soft rock layers by the fluid of soft rock as below.(1) The extrusion deformation of the soft rock will make the joints in the hard rock bear tensile. Thus, the joints which were closed would be drew open and made the slope have tension fissures.(2) The closer to the surface of the slope, ceteris paribus, the soft rock were easier to be transformed to be squeezed out. Under the influence of that, the joints located closer to the surface of the slope in the hard rock would be easier to be drew open to be tension fissures.(3) Ceteris paribus, the size of the tension fissures was related to the nature of the soft rock, its water content and the load the soft rock endured on earth and the thickness of the soft rock could also made influence to the size of the tension fissures.