Research On The Formation Mechanism & Revival Mechanism Of Typical Giant Landslides In Southwest China

Southwestern China is located on the eastern margin of Qinghai-tibet Plateau, with complex techonic setting, plenty of active faults, and various topograpgy types, epigenetic and superficial reconstruction is active.Giant landsildes are very conmmon in this area, which have caused enormous difficult to the geohazard prevention because of their large size and complex formation causes.A large number of engineering practice show that finding out the deformation model and mechanics of the landslide is the key to its prevention. Selecting examples of typical giant landslides in southwest China, commencing on the slope structure and the inducing factors(including earthquake,rainfall,manual excavation etc.), and using the geological analysis method, the geotechnical mechanics analysis method and the numerical simulation method, this paper made the research on their formation mechanism and revival mechanism. The reuslts acquired are as follows:(1) Giant landslide was defined according to the landslide volume, thickness, mechanism and control difficulty for its control.Using the composite classification method basde on slope characteristics, active characteristics and inducing fators, the giant landslide multiple-layer classification system was proposed.(2) An in-depth analysis of Donghekou landslide tanken as an example was made in earthquake-triggered landslides:it was suggested that the slope's formation mechanics is"shocking-tension-shearing -sliding"model.(3) An in-depth study of Panzhihua Airport 12 # landslide taken as an example was made in Rainstorm-induced landslides: through the geological analysis and numerical simulation, revealing the locking and progressive characteristics of landslide deformation.it was proposed that the slope's formation mechanics is"creeping -locking -collapsing"model.(4) An in-depth analysis of Jipazi landslide taken as an example was made in Rainstorm-induced landslides: it was suggested that the hydrodynamic pressure is the triggering fator of the landslide and the percolation model of groundwater in the slope controled its revival range, and the slope's revival mechani cs is"zoning-type creeping-tension-shearing"model.(5) An in-depth study of Badu landslide taken as an example was made in Manual excavation-induced landslides: it was suggested that the formation mechanics of the ancient landslide is"toppling-tension- shearing"model. The numerical simulationits reappeared its"zoning-type, classification-type creeping-tension-shearing"model.(6) Summarizing and presenting the geomechanics models of giant lanslides,of which rock landslides have 5 typical kinds, namely"shocking-tension-shearing -sliding"model,"sliding-tension-horizontal pusing"model,"creeping-tension-shrearing"model,"slipping-bending-shearing"model and"toppling-tension-shearing"model, and of which talus landslides have 5 typical kinds, namely"holistic creeping-tension-shearing"model,"zoning-type creeping-tension-shearing"model,"classification-type creeping-tension-shearing"model,"creeping-locking-collapsing"model and"creeping-tension-shrearing"model.