| Fushun city is an important coal capital in China,is a coal city,has an important strategic position in the northeast region,is an important economic pillar of the northeast region.The qiantaishan landslide is an oversize landslide formed by the perennial open-pit mining in the south side of the west open-pit mine in fushun city.Under the influence of natural and human factors,it has slipped many times in recent years,which seriously threatens the life and property safety and social stability of nearby residents.Therefore,it is necessary to carry out risk analysis for this landslide.In this paper,the qiantaishan landslide is taken as the research object.On the basis of extensive research results and data collected by predecessors,combined with field survey data,the landslide is numerically simulated by FLAC3 D software and its risk analysis is completed.At the same time,samples of landslide sliding body,sliding bed and sliding belt were collected.Mineralogy study was carried out based on XRD powder crystal diffraction test technology,and the sliding mechanism of landslide was discussed.The main results of this paper are as follows:(1)By collecting the previous research results and data and combining with the field investigation data,we have researched the geological background of the study area,such as landform,formation lithology,hydrology and meteorology,tectonic and earthquake,as well as the structural characteristics of the qiantaishan landslide,and comprehensively analyzed the possible influencing factors of the landslide.(2)The results of phase analysis of the samples at different positions of the landslide by XRD powder crystal diffraction show that the total amount of clay minerals in the sliding zone is significantly higher than that in the sliding bed and sliding body,and the clay minerals are mainly illite and montmorillonite.The water softening property of clay minerals makes them play a lubricating role between the sliding body and the sliding bed.The water absorption and expansion property of montmorillonite and illite will damage the shear strength of rock and soil mass,which is one of the main factors leading to the instability of landslide.(3)FLAC3D software was used to simulate the stress on the landslide of qiantaishan under three working conditions: natural,rainfall and excavation.The results showed that the stress concentration occurred at the slope shoulder position and the turning point of the slope from steep to gentle under three working conditions.Prone to slip damage.(4)The simulation results show that under the three working conditions,the horizontal displacement has a maximum value in the middle of the upper sliding surface,and the direction is northward.The vertical displacement is maximized at the slope shoulder and becomes smaller and smaller down the slope.The horizontal displacement is generally greater than the vertical displacement.(5)The numerical simulation of the maximum shear stress of the qiantaishan landslide shows that the plastic zone of the fracture zone has been connected under three working conditions,and the shear failure has occurred along the fracture zone,and the landslide has formed a sliding surface.Also calculated based on the strength subtraction three safety coefficient under the condition of natural conditions,respectively 0.967,0.733,0.924,working condition of excavation working condition of heavy rain three conditions are less than stability specification requirements,the comprehensive stress and displacement simulation and the result of the safety factor,draw thousands of taishan landslide is in unstable condition,with a larger risk. |
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