弹塑性数值流形方法在边坡稳定分析中的应用

针对现有数值流形方法只能进行弹性计算的不足，建立了一个能够反映完整岩块弹塑性变形特征的本构模型，并借助VC++开发了内置该本构模型的弹塑性数值流形程序。利用该程序模拟了含单节理岩样的室内压缩试验，分析得到了其强度和变形特性，计算结果符合实际的物理现象，表明程序是正确有效的。考虑到数值流形方法本身能够有效模拟材料的不连续变形，新增的弹塑性分析功能又可以反映岩石的强度特性，将弹塑性数值流形程序应用于某含有不连续面的岩石边坡的稳定性分析。并结合锚杆单元的使用，对比分析了不同锚固方案的加固效果。程序提供的变形、应力等计算结果表明:预应力锚杆不仅可以防止不连续面发生剪切破坏，增强坡体的稳定性，限制塑性变形的发展；而且可以使不连续软弱层面对岩体变形的消极影响得以减弱，起到提高岩体整体性的作用。

ELASTO-PLASTIC BASED NUMERICAL MANIFOLD METHOD FOR STABILITY AND DEFORMATION ANALYSIS OF ROCK SLOPES

An elasto-plastic model of intact rock is established and added to the existing numerical manifold method (NMM) for deformation and strength analysis. The corresponding VC++ program is then developed. For verification, several load simulations of rock specimens are carried out. The computed results show a favorable agreement with either analytical or physical test results. Since the NMM has the inherent advantage in dealing with rock discontinuities, the new NMM program equipped with the capacity of elasto-plastic analysis can be an effective tool for more geotechnical projects. . The stability of a rock slope is analyzed with the program. In addition, rock bolts are taken into account in the simulation process. Different rock bolting design schemes are compared through the numerical simulation. The computed results offer the displacement field, the stress distribution and the evolution of plasticity, which show that rock bolts can prevent the joints in the slope from cracking and the prestressed bolts can efficiently restrict the evolution of plasticity. In addition, it is observed that rock bolts combine the rock blocks on both sides of the joint to deform consistently, enhancing the entirety of the rock slope.