| Proposed the Gushui hydropower station is located in the southwest deep valley area in our country,is located in lancang river section,the eastern edge of qinghai-tibet plateau area,the geological tectonic movement,more development mountain ravines,along the layered leaning against dumping rock mass deformation is serious,the root of candy deposit landslide early is evolved by the dumping of the deformation of the deposit of the ancient landslide.Gendakan giant landslide deposit is located in the Gushui hydropower station dam site on the right bank of the downstream linear distance of about 4 km,accumulated on the thickness of the larger ice water accumulation,had several tectonic activities,the current along the quaternary loose accumulation and bedrock interface is slow slow slide,revival,the deposit landslide and slope table tension,shear fracture development,obvious signs of deformation of bank slope front,the original villagers live,because of its buckling deformation villagers all move.Deposit,therefore,to study the landslide and the resurrection of the evolution mechanism,and aims at the resurrection of bank slope front more dangerous deformation plugging river forecast analysis,the part for the plant are of practical significance for engineering construction,safe operation,the research results also provide some reference value for this kind of problem analysis.In this paper,from the root of the regional geological environment of Gendakan landslide deposit,detailed summarized deposit landslide deformation and failure characteristics,development characteristics and resurrection of 3D geological model is established to analyze its stress and strain,displacement,deformation and failure characteristics and further evaluate its resurrection evolution trend,combining the existing river near bank development characteristics of typical dump deformation of rock mass,analyze the root of the resurrection of the landslide deposit evolution process.Finally,study the forming condition of landslide blocking river and discriminant features,predict deposit bank slope front and river blocking formation mode.In this paper,the main research contents and research results are as follows.(1)Gendakan giant landslide was a deposit of giant ancient landslides,after multiple tectonic movement accumulated on its large deposit of ice thickness,at present the whole quaternary loose accumulation along the bedrock interface is slowly sliding.The Gendakan giant landslide scale vertical 850 m,transverse 700 m,deposit 80 m thick,on average,the overall volume is 3000×104m3.(2)Central deposit landslide and slope from front side slope vertical and horizontal development of tension and shear fracture.Deposit bank slope front and loose structure,and at the lowest high footrill found in secondary weak slip zone,bottom sliding surface is smooth,preliminary evaluation if the deposit slip deformation,again from whole large-scale deformation instability,may bank slope near the secondary weak slip zone formed part of imbricated towed slump.(3)The use of state of discrete element software for Gendakan giant landslide of the formation mechanism of simulation,it is concluded that the evolution process is roughly divided into four stages:(1)dumping of rock mass creep stage;(2)rock dump deformation increase stage;(3)dumping of broken rock mass,shear-slip plane through phases;(4)the dumping of falling stage of overburden rock mass sliding instability.(4)Falling body accumulation in bank slope front,crushing,loose deposit of bank slope,due to the deep valley incised and widespread bank slope instability,under the action of gravity in the instability of events lead to the first deposit river,formed in the river DAMS;With the uplifting of the river water level,the hydrodynamic conditions of DAMS and increasing ability of the erosion,cause the damming incidents;After the dam the river under the strong erosion made within short time form the high and steep slope on both ends of the DAMS,due to erosion time is short,at this time the river is still not completely removed the original DAMS;Dam,the erosion deposit front form high and steep slope topography,thus making slope front large-scale landslide events occurring again.(5)Using FLAC3 D finite difference software,respectively,the landslide deposit under the natural condition and rainfall conditions of shear strain increment and displacement and plastic zone cloud carried on the thorough analysis,calculation and analysis of the evolution trend of resurrection.Result is: the natural condition,the Gendakanof deposit landslide and better overall stability,the deformation and failure is given priority to with local tensile shear failure surface;Deposit under the condition of rainfall,the landslide and the local deformation and failure of relatively obvious,the resurrection deformation increase.(6)Finally,based on the principle of limit equilibrium method,the calculation analysis of deposit landslide and failure mode of the three main section,respectively,under the condition of the working condition of natural,rainstorm,earthquake calculation section as a whole and the stability of a slope from front,the results for the bank slope front sliding block structure of the part of the deposit is loose,and airport surface is good,under the effect of working condition of rainstorm,earthquake and other external cause,may produce small slump.Deposit of bank slope front and blocking the formation of jiang movement condition,the horizontal distance and more in-depth research into the dam height,predict the formation process of the landslide blocking river DAMS as: deposit bank slope and trailing edge creep cracking,leading edge shear deformation;Sliding surface,accelerate the decline;Disintegration of collision and impact into the dam. |
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