The Rock Strength Characteristics Research Of Karst Belt

Southwest karst mountainous in our country is the high incidence of large landslides disaster, wherestructural faults aspect, dramatic changes in lithology, dissolution fissures, sinkholes, caves, undergroundrivers and other highly developed karst topography, its presence on the rock landslide unstable modes andstability predicted pose a great hidden cause geological disasters anticipation mistakes.In this thesis, based on the karst mountain landslide–Jiweishan landslide, in the survey of geologicalenvironmental conditions、combined the previous studies, analyzed the sliding mechanism of Jiweishanlandslides; througu numerical simulation to reserchthe the strength characteristics of rock landslide flankand leading edge in Jiweishan karst area, reveal rock strength variations under the circumstances of karst,and landslide stability evaluation of Jiweishan do in-depth research, The main contents and resultsinclude the following:1、Through field surveys and collect relevant information, analyze and summarize the Jiweishanlandslide disaster occurred and is conducive to the structure and impact of mining geology, the landslideablation in flank has a large extent reduce the front of the sliding body key block strength, shear induceddamage caused landslide disasters.2、Using the finite difference software FLAC3Dto numerical simulation the different rates karst rockunder different stress conditions,Analyze the impact of different rates of karst development and differentnormal force of rock deformation and strength characteristics. The results show:With the increase of therate of karst development, the greater of shear displacement of the sample rock, the main failure modechanges from shear slippage damage to cut damage.,and the shear stress of the sample rock becomessmaller, the maximum shear stress decreases;The shear curve of the sample can be divided into threestages: the linear growth phase, peak and post-peak phase slip stage;Karst rock in same rate samples inthe process of the shear, the longer of nonlinear changes to the larger stage of normal force, At the sametime as the peak intensity of the normal stress increases;Under same normal stress conditions, the greaterof the development rate of karst rock, the shorter of nonlinear stage of shear displacement curve changes,and the lower of the peak intensity.3、Unbalanced reasoning transfer method using Jiweishan landslide stability analysis,Comparison the analytical solution methods based on the overall stability analysis and key block theoryanalysis,Analysis of the results of these two methods, derived the key block theory calculation results ismore secure and reliable.The results have shown that the two theories with the increasing rate of karstrock,safety factor obtained are gradually reduced, and the magnitude of the safety factor decreases withincreasing the rate of decrease of karst development.