Stability Analysis Of Soil Nailing Slope In Beijing Area Based On Strength Reduction Method

A soil-nailed side slope which is located in Beijing area is taken as the research object in this paper.On the one hand,by comprehensively considering the engineering geological conditions in Beijing area,the unsaturated soil strength theory is introduced,and then,the unsaturated soil is considered as the main factor to influence the foundation pits slop stability in Beijing area.On the other hand,by comparing several kinds of stability analysis methods,the strength reduction method is mainly used in this paper to analyze soil-nailed side slope stability,and then with different supporting parameters,the stability of the soil-nailed side slope is studied systemically, which references for optimization of support design.At last,a new idea is put forward tentatively for the side slope stability analysis of the areas with unsaturated soils. Combining with practical engineering examples,the strength reduction method is flexibly applied to realize the dynamic stability analysis.The following is the research results of this paper:1) In order to avoid the difficulties to measure and calculate the suction,the moisture content is introduced here to research the influence of the water on the unsaturated soil stability.This method is based on tests,and it is approximate to some extent,but it can be applied conveniently and effectively in the practical engineering.So it is a feasible method.2) By using strength reduction method and analyzing the value of the soil-nailed side slope safety factor and the position and shape of the most dangerous slip surface, the influence of the nail length,nails distance and slop angle on the side slop stability is systemically studied.3) Unsaturated soil strength theory in which the moisture content is taken into account is introduced,and a new way to analyze the side slop stability in unsaturated soil area is put forward,which makes it possible to analyze the side slope stability better.4) Combining with practical engineering examples,a finite element model is built. According to finite element strength reduction method and unsaturated soil side slope stability analyzing method,the soil nailing side slope stability is analyzed.By comparing construction situation,the applicability of the strength reduction method for the complicated engineering and the correctness of stability analyzing method for unsaturated soils area are further verified.