Research And Application On Quxiao Highway Slope Control Techology

In China, many natural side slopes exist because of the large amount of mountainous areas, and many high artificial side slopes come into being inevitably because of the rapid development of infrastructure projects. These side slopes become a serious threat to project safety and surrounding environment. Meanwhile, in south China, the situation of unstable geology, frequent earthquakes, and joint fissure development makes the study on side slope stability very practical and important. In this thesis, taking the side slope of Qujing expressway as an example, a research on determining the safety factors of side slope stability is introduced.The following contents are included:1. introducing the significance and contents of the research, reviewing domestic and overseas researches on side slope stability, and summarizing stability analyzing methods and landslide treatment technology;2. analyzing the mechanism of side slope deformation and damage, introducing landslide types and characteristics, and expounding the principle and meaning of the analysis, and also the stress and major factors of the side slope deformation and damage;3. expounding the secant modulus, the strength criterion, the flow rule, and the size deformation hypothesis often adopted in side slope stability analysis, and also expounding the finite element strength reduction, the margin of strength, the strength reduction principle, and etc..4. discussing the stability analysis when the side slope being loaded, which includes the frequently-used limit equilibrium method, the finite element strength reduction, and the finite difference method, and then comparing the safety factors worked out by those methods through an example.5. in combination with an engineering project, separately setting up a finite element calculation model and a finite difference calculation model, through the equivalent plastic strain distributions before excavation and during different excavation stages, then working out the stability safety factors and accordingly proposing several ways in evaluating the side slope stability; at last, treatment methods are proposed for the side slope of Qujing expressway.In this thesis, through comparing the safety factors worked out by several ways based on an engineering project, the reliability safety factor is recommended to be used to evaluate the side slope stability.