Application Of Strength Double Reduction Coefficient Method In Design Of East Tai Shan Slope

The traditional finite element method (FEM) based on the strength reductiontechnique defines that shear strength parameters of soil (cohesion c, friction tan φ)should use the same reduction coefficient in clay soil. However, the importance ofcohesion and friction keeping the stability of slope vary with slope ratio in practicalprogram. Therefore, the reduction coefficient of cohesion and friction should bedifferent. In order to analyze which one is more important of cohesion and frictionkeeping the stability of slope in different ratio slope, the thesis analyzes the stabilityof slope by comparing with three different conditions:1. reducing cohesion, noreducing friction,2. no reducing cohesion, reducing friction,3. reducing cohesion andfriction at same time, the ratio of reduction coefficient of cohesion to friction’s is k.By comparing to the different conditions, we note that: when the angle of slope β isless than45°，the function of friction is more important than cohesion’s, otherwise,the function of cohesion is more important than the friction’s. Also, by varying theratio k, we can know that: when the angle of slope β is more than45°, the safetyfactor of slope calculating by FEM is least, so, the traditional FEM is a safe methodcompare to FEM adopting different reduction coefficient. when the angle of slope β isless than45°, the safety factor of slope is a mid value, so, the traditional FEM is aslightly safe method, comparing to the safety factor calculating by traditional FEM,the range of error of the least safety factor is in4%. From the perspective of safety,the value k should be chose when the safety factor is being least, by analyzing thevalue k when the slope ratio is1:0.5、1:0.75、1:1.0、1:1.25、1:1.5、1：1.75、1:2respectively, we find that: when the slope ratio is more than1:1.0, the best value kshould be1.0, when the slope ratio varies from1:1:25to1:1.75, the best value kshould be0.8, when the slope ratio is1:2.0, the best value k should be0.6. At last,according to the about analysis results, we use the best value k, which is1.0becauseof the slope ratio more than1:1.0, in east Tai Shan program of Wo Long Bay in DaLian city. By numerical simulation, we can obtain stress, displacement and the safety factor of slope, and then, we can conclude that the treatment method by anchor isreasonable and feasible, which can provide reference for similar programs.