The Study On Constitution And Failure Patterns Of Water-resisting And Mud-resisting Rock-soil Plates

Due to the thickness of water-resisting and mud-resisting rock-soil plates,located in the water inrush and mud burst disaster-causing structures between the excavated surface and the front of the excavated surface or between the excavated contour line and outside of the excavated contour line,is less than the minimum safety thickness of the rock-soil plate,and under the stress of the underground water of the water inrush disaster-causing structure or the stress of the clay of mud burst disaster-causing structure,water-resisting and mud-resisting rock-soil plate is unstable,water inrush or mud burst disasters are triggered in tunnel excavation.Based on the cases of water inrush and mud burst disasters survey in decade,this paper summarizes and proposes the constitution types of the water-resisting and mud,resisting rock-soil plates causing water inrush and mud burst disasters.The rock-soil plates are the various sizes of broken rock blocks with or without clay(rock particles and sand-cobbles),the fractured rocks filled with or without fractured clay,the clay or fault gouge,the intact rock,and the water-resisting and mud-resisting rock-soil initial support(lining)plates.On the basis of considering the influence of various factors on the damage of rock-soil plates,this paper puts forward failure patterns of the water-resisting and mud-resisting rock-soil plates.The failure patterns are seepage(collapse)failure,softening failure,shear failure,burst failure,and bending failure.It also analyses the interrelations between the constitution types and the patterns of the water-resisting and mud-resisting rock-soil plates.According to the test results of the intact plates,intermediate and marginal fissure rock plates of limestone and sandstone,this paper has analyzed the relation curves of the load-transverse strain,the load-vertical displacement,the transverse strain before rupture and time,and the transverse vertical displacement before rupture and time.Therefore,the regular patterns have been figured out that change in two phases.Meanwhile,the power function relationships of the intact and fissure rock plates of limestone and sandstone have been initially established through the regression analysis of the relation curves of the rock plate failure load and thickness.