Study On Fuzzy Evaluation For Stability And Reinforcement Technique Of Expressway Slope

Owing to the require of engineering, the stable rock mass or soil mass is destroyed in a certain degree to form the new artificial slope when constructing expressway. The rock and soil body as a structure have the own intensity and stability of material and structure. However, the intensity and the stability will be descended largely for influence from the environment and human activities. Therefore, after analyzing the stability of expressway slope, we should take some measures to reinforce and harness the instability ones in order to avoid the needless loss.Base on the date of former and the means of in-house and in-situ test and theoretical analyzes, the thesis has made the induction and the summary to slope stability analysis and study actuality of reinforcement and harnessing for expressway slope. Taking the Guilin-Liuzhou expressway as the object of study, it has found some useful conclusion by researching the influential factor, distribution feature and formation mechanism of slope deformation and destruction systematically and deeply.By surveying, the main deformation and destruction mode of the slope in the researched section of Guilin-Liuzhou expressway are landslide, collapse, and there is desquamation a little. The cause of formation relates to landform and the feature of geologic environment. The main influence factors are divided into physical factor and artificial factor. The physical factor includes landform, geologic environment, precipitated and ground water and rock weathering. The artificial factor includes highway construction and the cognition degree to slope deformation and destruction. The former is the basement to control the progress, and the latter accelerates it. The stress state in slope body will change along with the deformation of artificial slope and bring redistribution and stress concentration.Based on the feature of the deformation and destruction mode of the slope in the researched section of Guilin-Liuzhou expressway, we evaluate the slope stability divisionally adapting the theory of fuzzy mathematics through analyzing. We adapt secondary fuzzy evaluation model, choose 14 factors which can influence the stability, confirm their threshold value and standardize them. We use the expert evaluation method and the formula method in evaluating factor. The factor weight number is determined by method of inversion in computer program. And the result shows that the section can be divided into stable zoneâ… , local instable zoneâ…¡and instable zoneâ…¢. We should adapt different and reasonable harnessing measures to different slope region on the basis of the actual stability.Nowadays, because the reinforce techniques are not mature, the technic route map for reinforcing the slope and the flow chart for optimizing design process have been established inhere so that the engineers can choose the reasonable and feasible design plan to reinforce the slope. Otherwise, the writer has researched deeply the technique of prestress anchored cable which is in common use, and find that the stress mechanism of the tensile anchored cable and the forced anchored cable are not all reasonable. So we should do best to use the pull-pressing anchored cable in engineering.