The Disciplinarian On The Development And Distributing Of Geo-disaster & Stability Evaluation Of The Bank Slope In Wudongde Reservoir Area Of The Jinshajiang River (from The Reservoir Former To The Estuary Of Longchuanjiang River)

During the process of impounding and normal operation of the reservoir, the primary natural balance condition of bank slope is distoryed, which changes the shape and stability of the slope,and then causes the geo-disasters,such as collapse, landslip and land slide. After the reservoir comes into being, the geological condition along the bank will be changed evidently, at the same time, the rise of the water level of the reservoir causes the rise of the river's partial corrasive datum plane and the water table, and the dynamic change of the water table, so the bank slope is reconstructed strongly. The unstabilization of bank is one of the slope's normal deformation modes in hydrodynamic engineerings.Wudongde hydrodynamic power station is the first one of the four hydrodynamic step along the downriver reach of the Jinshajiang River,whose capacity is 8.7 million kilowatt. According to the earlier blue print that the normal water level is 975m and the height of dam is 265m, its rear is near to Midi village, located on the east to Panzhihua city, and its trunk is up to 206.7 kilometers long.On the basis of the investigation of the geological condition of the reservoir area,this thesis partitions the structure style of bank slope and separates the bank from them , analyses the phenomena of deformation and breakage( the disciplinarian on the development and distributing of landslide, landslip and crag), studies the mode and inducement of the deformation and breakage about the bank slope, and evaluates the stability of landslide, landslip and crag & bank slope. At last, it evaluates the stability of the bank in segments and takes measures against the unstability of the bank. The main conclusion is as the following: (1) The left and right bank of the trunk in research area is 195.4 kilometers long. in which the length of soil bank is 49.3 kilometers (25.23 percent ), feeble- metamorphosed rock bank is 41.3 kilometers (21.14 percent ), carbonate rock bank is 14.7 kilometers (7.52 percent ), clastic rock bank is 90.1 kilometers (46.11 percent ). The bank of the three main anabranch is 27.5 kilometers long ,which are all clastic rock bank.(2) The structure types of bank slope in the reservoir area can be divided into many segments: soil bank 25 segments (coasting deposit: 4 segments, colluvial deposit: 11 segments, accretion: 10 segments ); feeble- metamorphosed rock bank 12 segments(direct-dipmiddling-obliquitystrata: 9 segments,anti-dip middling-obliquity:3 segments); carbonate rock bank 5 segments (direct-dip mild-obliquity strata: 3 segments, anti-dip mild-obliquity: 1 segment, anti-dip middling-obliquity: 1 segment); clastic rock bank 20 segments (direct-dip mild-obliquity strata: 5 segments, anti-dip mild-obliquity: 14 segments, transverse-dip mild-obliquity: 1 segment).(3) The phenomena of the deformation and breakage about the bank slope in the reservoir area mainly includes: langslide, landslip and crag, in which there are 32 langslides(the over-scale: 37.5 percent; the good-scale: 40.6 percent; the medium-scale: 21.9 percent ),18 landslips and crags (all exceeding the medium-scale, the over-scale and the good-scale: 89 percent).(4) The breakage and reconstruct of soil bank slope in reservoir area is mainly he models of erosion-ablation, recessional collapse and holistic slipping.(5) The types and the modes of deformation and breakage about the rock bank slope can be divided into four styles in the reservoir area:The―three sections‖of sliding - tension cracking - shearing model in mild-obliquity strata; the creep-tension cracking or consequent sliding model; the creep (bending)-shearing or sliding-shearing model by interbedded soft zone in direct-dip middling-obliquity strata; the bending - toppling model in anti-dip middling-obliquity strata.They are stable relatively in transverse-dip strata, influenced by superficial cranny, whose deformation and breakage model usually is partial and small-scale landslides and landslips,etc.(6) Rainfall, corrosion and anthropic engineering activity are the three main inducement of the deformation and breakage about the bank slope in the reservoir area.(7) The evaluation of the stabilization of 32 langslides is as the following: In current conditions, there are 19 rather stable one, 6 rather unstable one and 7 unstable one; After impounding, there are 14 rather stable one, 6 rather unstable one and 11 unstable one.The evaluation of the stabilization of 18 landslips and crags is as the following: In current conditions, there are 10 rather stable one, 7 rather unstable one and 1 unstable one; After impounding, the stabilization of the crags will not be changed, the stabilization of some landslips will be depressed, which will be under the water level.(8) Based on the quantitated result of the stabilization of the bank slope in the reservoir area, the good-stabilization bank slope is 54.8 percent of the total segments and 83.3 percent of the total length, the not-good-stabilization bank slope is 45.28 percent of the total segments ,but only 26.7 percent of the total length.(9) Based on the actual condition of the bank slope in the reservoir area, it takes the meatures to prevent the bank slope off its unstability: inspecting and forecasting, preventing rainfall and surface water from infiltrating, preventing the backyard of the slope from loading severly, preventing the frontage of the slope from corroding and unloading, comprehensive treating, exploiting land resources protectly and so on.