Fragmentation Mechanism Of Original Rockmass In Touzhai Landslide

Emeishan basalt, which is distributed widely in the juncture region of Yunnan, Guizhou and Sichuan provinces, is a kind of volcanic rock series susceptible to LHLLDF (Large high-speed Long-runout Landslide-Debris Flows) hazards, and is often built as foundation rockmass and high engineering slopes of large and giant hydropower projects. The researches on Emeishan basalt-LHLLDF is of great theoretical and practical significance. Previous relevant studies mostly focus on the kinematics of rock avalanche-debris flow and triggers of events. The relevant researchers focus on the kinesiology of the fragments and triggering factors of the landslides, but neglect the distribution of the extremely broken fragment along the way. So far, there are no system study about the reason how the instable rock mass transform the extremely broken fragment. The object of this paper is to investigate the grain size distribution of the deposit of landslide and the size distribution of broken rock mass in solid rock, then through the analysis and comparison of the grain size distribution, aim to make clear the process of fragmentation of the instable rock mass. The specific studies were as belows:(1) The study of grain size distribution of the deposit of Touzhai landslide. This paper takes the Touzhai landslide as study object, combining with the laboratory experiment, through the field sieving experiment, investigation of the grain size of leaching block stones and huge stone and clay sampling analysis, the grain-size composition of deposit body is understood comprehensively ranging from large to small.(2) The study of the size of broken rubble in solid rock. Analyzing the fractal feature of the structural plane in the surface of rock mass and taking photos of the representation of broken plane of the solid rock. Through the software named ArcGIS dealing with the origin graphics, we can get the size of each rubble segmented by the structural plane and analyze the size distribution of the broken rubbles.(3) The analysis and comparison of the size of the broken rubble in solid rocks and the size distribution of the fragment in deposits. Analysis and comparison the relevant data of the size distribution of the broken solid rock and deposit, then make the correlation analysis of the mass accumulation curves of that. It is aim to make clear the difference between the size distribution and analyze the reason for the difference.(4)Discuss the fragmentation mechanism of the basalt. Through analyzing the evolutionary process of the structural plane of the Emeishan basalt of columnar jointing during the primary structure, late reformation and epigenetic reformation. We aim to state the evaluation of the structural plane contribute to the fragmentation of rock mass.