Abstract:Taking the reinforced typical high cutting slope along Lanzhou South Ring Expressway as the research object, a three-dimensional numerical model is established for the selected typical slope by using AutoCAD and ANSYS software. On this basis, the finite differential software FLAC3D is used to evaluate the stability of the slope under the earthquake condition, so as to provide reference for the protection and safety design of loess-like high slope works. It is concluded that the slope is stable when the horizontal earthquake acceleration is 0.1g and 0.2g; the slope is basically stable when the horizontal earthquake acceleration is 0.3g; and the slope is unstable when the horizontal earthquake acceleration is 0.4g. The lattice bolt support bears large part of the tensile stress and shear strain increment, et al., with remarkable effect, and it plays an important role in slope stability. The specified seismic intensity for the highway construction region is 8 degrees with the designed seismic acceleration of 0.2g; thus, the selected lattice-supported slope is in a stable state (the stability coefficient is 1.15) under earthquake conditions, which can meet the specification.

Abstract:With the development of the country and society, people pay more and more attention to the ecological environment. In the process of economic development, there are a large number of abandoned pits left by mining, and the treatment of these pits is urgent. As an effective method for treating high, steep and smooth rock walls, the floating platform is widely used in practice. However, most analysis of the stability of the platform is based on simple formula. In this paper, a kind of concrete floating platform structure suitable for the treatment of steep rock walls in mines is designed, and the formula for calculating the stability of the floating platform is refined, and the stability of the floating platform is analyzed by combining with FLAC3D numerical simulation software. The research results show that the concrete floating platform is more practical for the treatment of steep rock walls in mines.

Abstract:The bearing capacity of large diameter piles in Dalian is simulated with FLAC3D software, and the bearing capacity of conventional piles and bell-out piles are compared and analyzed. The results show that the FLAC3D software simulated changes in Q-s curves fit the actual measured ones for conventional piles under the same load, indicating that the established FLAC3D model is suitable for study of those piles. The FLAC3D model is used to analyze stress of bell-out piles and conventional piles under the condition of 6000kN load and the same pile diameter. Under the condition of the same stress at the top of pile, the stress at the end of pile is reduced by 50%, and the stress condition at the end of pile is improved. Under the condition of the same pile length, the bearing capacity of the bell-out pile with reduced diameter is studied. The material used is 61.2% of the conventional pile. The simulation results show that the bell-out pile with reduced diameter can meet the engineering load requirements and reduce the cost. It is suggested that the original design should be revised to provide a theoretical basis for similar projects.

Abstract:Take a mountain side slope in Xiuyan County of Liaoning Province as an example, the potential sliding surface is found out with trenching, drilling and large-scale shear tests. 3D numerical simulation is made on the side slope with FLAC3D software to analyze the relationship between stress and strain in order to determine the area with large deformation and stress concentration; meanwhile by using strength reduction method to draw safety factor of the landslide and evaluate its stability. Comparing the data obtained in the deformation monitoring points arranged at the tensioning fractures on the back edge of the slope with the numerical simulation results, the reliability of the numerical simulation can be verified to provide the basis for the anti-sliding design of the side slope.

Abstract:Take borehole HSNCM48-1 as an example, which was at Line 48 of Heishigou ore section of equipped exploration mining area in Dulan County of Qinghai Province, FLAC3D numerical simulation software was applied to simulate the deformation of tunnel excavation; and according to the simulation results, the support measures and monitoring points were determined. Comparative analysis was made on the numerical simulation results of vertical displacement, horizontal displacement, the total displacement and plastic zone before chamber excavation supporting, and on the real values by multi-point displacement meter before and after monitoring points excavation supporting as well as the simulation values calculated by FLAC3D simulation software respectively. By the comparative analysis on the calculation results, the deformation of chamber surrounding rocks simulated by numerical simulation software can be obtained, which is very important for the displacement field analysis and the supporting measures determination.

Abstract:Shield-driven is a key technology of shield-construction, but analysis on its stability is nearly a blank without calculation analysis methods, and the design mainly depends on the experience. Based on the design and construction of Tianpingjia Line 6# of Guangzhou metro, the paper made the analysis on the stability by means of finite difference procedure FLAC3D to simulate shield-driven, emphatically analyzed the stress field, destroyed field, and displacement field in different starting segment reinforcing ranges. The paper also discussed the reasonable thickness and strength. The research result is hopeful to provide theoretical basis and instruction for the design and construction of shield-driven.

Abstract:Numerical simulation was made on water filling preloading for reinforcement of oil tank foundation by finite difference program FLAC3D， and analysis was made on the deformation characteristics and the shape of large oil tank foundation. Comparison was made on the result and monitoring data with very good uniformity.