为优化非连续变形分析(Discontinuous Deformation Analysis for Rock Failure)中计算精度和计算时间的关系,文章提出了DDARF多尺度网格划分方法,分别建立了多尺度网格和均匀网格的单轴压缩模型,并进行了数值试验和室内试验的对比:将多尺度网格划分方法应用于大型地下洞室开挖,对洞室附近区域进行了针对性研究。结果表明:DDARF多尺度网格与均匀网格模型单轴压缩试验相比,网格数量相同时提高了裂隙附近的计算精度,裂隙扩展规律与室内试验更为吻合;多尺度网格划分方法应用于地下洞室的开挖,在相同计算精度下减少了计算时间,提高了效率,位移规律和FLAC计算结果吻合度较高;多尺度网格划分方法完善并加强了DDARF模拟岩体裂隙扩展的功能.对大型岩土工程稳定性的优化分析具有重要的实用意义。
To optimize the relationship between calculation accuracy and calculation time in the process of DDARF (discontinuous deformation analysis for rock failure), a DDARF multi-scale meshing method is set up in this paper, in which uniaxial compression models with multi-scale meshes and uniform meshes are established and a comparison between a numerical test and laboratory experiment is carried out. The multi-scale meshing method is applied to study areas adjacent to large underground caverns. Results show that the DDARF multi- scale meshing method is feasible; compared with the uniaxial compression test in the uniform meshing model, the calculation accuracy around the cracks is improved with the multi-scale meshing model using the same total mesh numbers, and the crack propagation law is more consistent with that obtained by the laboratory experiment; with the DDARF multi-scale meshing method applied to a large underground excavation, calculation time is re- duced and efficiency is improved while the accuracy of calculations is maintained; and the displacement law is well aligned with that of the FLAC calculation results. The multi-scale meshing method improves the ability of the DDARF model to simulate propagation of cracks in the rock and has practical significance in the optimization analysis of stability for large geotechnical engineering.