Stability Analysis And Numerical Simulation Of Excavation And Supporting Of High Cut Slope

The Guangxi Longlin–Baise Expressway is an important part of the Shankun Expressway, which is included in the China National Expressway Planning Network-"7918"Network, as well as an important section of the highway of Hezhou to Longlin, which is included in the Guangxi Highway Planning Network-"6 horizontal 4 vertical"Network. At present, a large number of excavation and high cut slopes have arisen in the construction of mountainous highway. The stability of these slopes will directly affect the progress and security of project, also is one key aspect of reducing construction cost. In general, slope stability involves two stages, that is, the one during excavation and the long-term one after excavation. Therefore, it is of great significance to analysis the slope stability after excavation and study the process of excavation and support.Based on the high slope project located in Longlin-Baise expressway K146+160- K146+440 section, this paper study it's stability with systematic approach. The specific studies are as follows:(1)Starting with the influencing factors and potential failure mode of slope, quantitative analysis is made on the stability of the typical section (K146+300).(2)The main mechanical parameters of the high slope rock mass are estimated by use of the Generalized Hoek-Brown Criterion based GSI method, which provid the basis for quantitative evaluation.(3)With limit equilibrium method and strength reduction method based on FLAC2D, according to the mechanical parameters , a deterministic analysis of slope stability is carried out on the typical section (K146+300), also corresponding support treatments are undertaken.(4)In order to select the random variables for a probabilistic analysis ,a Sensitivity analysis is performed, and then a probabilistic slope stability analysis is carried out with monte-carlo simulation method on the typical section (K146+300).(5)The excavation and support process of high slope are simulated by three-dimensional fast lagrangian method. The pattern of deformation caused by excavation and stress state under complex geological conditions are researched. The distribution of maximal shear strain increment and plastic areas are analyzed. The safety factors of the three-dimensional slope are calculated. All of these results provide the basis for construction.