Study On 3D Geologic Feature And Stability Of Liangjiaren Deposits

Liangjiaren deposits are located on the left bank of the Tiger-Leaping-Gorge of the Jinsha River ,the area of this deposits is about 5．37km~2 and the total volume is estimated to be about 4×10~8m~3．Because they are lager ,their current stability affects the choice of the dam site of the Liangjiaren hydroelectric power station . This paper studied the Liangjiaren deposits , and researched the 3D geologic feature of the deposits with the integrated geophysical methods and the 3D modeling methods ;By analyzing physical geography condition and geological background of the investigated area , this paper researched the genetic mechanism ;Base on these , the author evaluated qualitatively their stability ,and analyzed the stability of the deposits with Energy Method Uppen bound limit analysis quantificationally . This paper analyzed the formation mechanism of the deposits by the software FLAC3D .The result of comprehensively physical exploration shows that the deposits are very thick , the thickest part is 200m.There are two chair-shape sags and several lateral belt-shape grooves on the bottom interface ,which is steep ,gentle, steep from high to low .The thickness of the deposits from upriver to downriver is thick ,thin ,thick ,and from high to low is thin ,thick ,thin .The genetic mechanism research shows that they belong to composite geological body of the coupling of Earth's endogenic and exogenic geological process . They have multi-stage, mixingorigin characteristics.The qualitatively evaluation and 2D stability calculation shows that their integerstability is good , the local stability is bad. The formation mechanism analysis resultabout theⅠpart of the deposits shows that there is the local latent slide zone ,of whichthe scope is small ,the result is somewhat consistent with the qualitatively evaluationand 2D stability calculation .