Research On Monitoring Scheme And Stability Evaluation For Cutting Slope Of Tanheng West-Line Freeway

With the constant extension of the freeway in mountainous and hilly area, the construction difficulties increase unprecedentedly.That leads and induces geological hazards, like the freeway landslide, which are increasing remarkably and gradually becoming the focus of our society. Therefore, research on stability analysis,safety monitoring and integrated control of freeway,especially in mountainous and hilly region,has great significance.The thesis is about the research on stability analysis and safety monitoring, sets the cutting slopes of Tanheng (Xiangtan to Hengyang) west-line freeway as the research object. Summarizes and analyzes the basic principle and characteristic of slope strength reduction FEM and the features of freeway cutting slope deformation failure, The main contents are below on this basis.(1) This thesis makes a systematic exposition and analysis of the basic theory of the strength reduction elastic-plastic finite element method. On this basis, it also makes a relatively comprehensive exposition of the influencing factors of the calculation accuracy of strength reduction FEM. Ideal elastic-plastic model,Mohr-Coulomb criterion and the non-associated flow rule are chosen to be the basis of the calculation and analysis.(2) Analyzes the instability criterion which is used in the slope stability analysis with the strength reduction FEM. The thesis holds that a Common problem which exists in three instability criterions is the determination problem of iteration number and convergence permissible limits. Meanwhile, there is a consistency in these three criterions to a certain extent. The criterion of convergence is selected as the instability criterion of the slope involving in this thesis.(3) Based on the engineering geological data,field survey and test, analyzes and evaluates the engineering geological conditions and the influencing factors on stability of the cutting slope of Tanheng west-line freeway comprehensively. Using the basic theory of strength reduction FEM and the aid of well-known FEM software ABAQUS, analyzes the stability of a typical slope of Tanheng west-line freeway, obtains the safety factors and the potential most dangerous sliding zone of this slope in natural state and seismic status. Carrying out relatively thorough analysis for the results of the stability computation and conclusion gained which can help to deeply understand the breakage mechanism of slope distortion. It is also held that the instable possibility of the slope in the thesis is great, so it needs to be strengthened. Meanwhile, it is proved that here is a consistency in these three criterions based on the calculation results.(4) Three reinforcement schemes are proposed and comparative analyzed according to the engineering geological condition and lithologic features of the slope, and suggests that the Scheme of prestressed anchor cable + retaining wall + plant framework protection be adopted.(5) Studies the theory and method about design of slope monitoring, on this basis, researches on the design of safety monitoring of the slope are given.The research results have certain reference value for the study on monitoring and stability analysis for the cutting slope of freeway in mountainous and hilly area.