Stability Analysis of Composite Soil Nailing Wall Based on Improved Energy Method

Composite soil nailing wall is widely used in slope support because of its low cost and safety, but its global stability still needs more accurate calculation. Based on plastic limit upper limit analysis and vertical strip partition method, the calculation formula of stability coefficient was derived for prestressed anchor composite soil nailing wall. FLAC3D and GeoStudio were used to calculate and analyze an engineering project supported by composite soil nailing wall in Lanzhou City, and the feasibility and correctness of the derived formula were verified. Finally, the grey correlation analysis of the sensitivity of the derived formula was analyzed. The results show that for calculating the stability coefficient, the limit equilibrium method needs to consider the complex force analysis, while the energy method can well avoid the inter-slice force, making the physical meaning of the formula clearer. The formula introduced in this paper is more efficient and feasible. The stability coefficient is most sensitive to the internal friction angle, followed by slope angle, cohesion, and finally unit weight of soil.