The Application Of FLAC Methods On Stability Analysis Of Slopes In The Three-Gorges Reservoir Area

The geological disaster cure in the Three Gorges Reservoir Area is a very huge and complex engineering. Adopting scientific and correct method of slope stability analysis has been brought forward in the geological disaster cure in the Three Gorges Reservoir Area, and has become an imminent and key research topic. Houzishi landslide in Fengjie and Beimenpo landslide in Wushan are used as examples in this paper. Researching the application of FLAC method in the geological disaster cure in the Three Gorges Reservoir Area, and associating FLAC method with strength reduction method, used for calculating of landslide stability factor. Some preliminary conclusions are obtained by much calculating, comparing FLAC method with thansfer coefficient method.(1) The combination of FLAC method and strength reduction method, used to slope stability analysis in the Three Gorges Reservoir Area, is a certain and useful method. It can reflect the law of changes of stress and strain in landslide, can traceing the changes of displacement, velocity and stress of the keypoints with the time. It can obtain landslide stability factor at the same time that is often used in engineering design.(2) Comparison analysis suggester that the results of FLAC method are agreement with those of thansfer coefficient method basically. It reflects that using FLAC method to analysis slope stability is correct. But landslide stability factor obtained from FLAC method is smaller than from thansfer coefficient method in analysising of Houzishi and Beimenpo landslides.(3) The angle between tangent line direction of sliding plane and horizontal direction(α) is smaller, i. e.sliding surface is mild, corresponding C,φat vertical direction interface are larger, and sliding surface is simpler, fault ,joint,fracture are less, rock and soil block is fairly simple(such as homogenous soil-slopes), collecting much datum,division of units are ample, the results of stability factor of thansfer coefficient method approximate with FLAC method.(4) The landslides stability calculating of FLAC method keep much geological tetonic characteristics of actual landslides, and can reflect the distortion coordination between soil and rock, or rock and rock, can reflect the coupling action between groundwater, reservoir filling, support structure and soil and rock block. The force and moment equilibrium are all concerned. Conquering the defect of much assumption and reduction of thansfer coefficient method.