基于变形控制的含软弱夹层顺层边坡治理

THE TREATMENT OF BEDDING SLOPE WITH WEAK INTERLAYER BASED ON THE CONTROLLABLE METHOD OF DEFORMATION

坡脚开挖后,含软弱夹层顺层边坡往往在支挡结构未及施作时便沿软弱夹层发生滑动失稳,施工难度大。基于边坡开挖时空效应与结构协同工作等原理,提出一种变形控制工法,采用有限元模拟设计了锚索分步张拉路径,形成锚索抗滑桩变形控制治理方案,并应用于平乐互通顺层边坡。结果表明:一次张拉条件下,不同锁定系数能使锚索受力更为合理;锚索预应力变化受边坡开挖时空效应及支挡结构协同作用影响,坡体位移和锚索预应力增量与边坡开挖时步的关系之间存在特征关联;结合变形控制工法可得动态调整张拉时机、顺序及锚固力大小的锚索分步张拉路径;有限元模拟揭示该方案在平乐互通顺层边坡上治理效果明显;实践表明,该方案关键工序及监测措施具有可行性,坡体变形得到有效控制,平乐互通顺层边坡整体处于稳定状态。

After slope excavated at the root, sliding often occur in bedding slope with weak interlayer when the reinforcement was not constructed, which makes the processes more difficult. Based on the principle of tau-effect and structural synergy, a controllable method of deformation was proposed in this research. A cable tension path was designed by finite element method, and the treatment method of anti-slide pile and anchor cable was generated. The treatment of Pingle interchange bedding slope was improved by this scheme successfully. The results indicate that the force of anchor cable is more rational with different locking modulus than that with same modulus under the condition of one-time tension. The prestressed fluctuation of anchor cable is influenced under the tau-effect of slope excavation and the structural synergy. There are characteristic correlations, between, the displacement of slope along the time excavation steps, and, the prestressed increment of anchor cable along them. Based on the controllable method of deformation, the cable tension path can be obtained by dynamically adjusting the tension time, sequence and anchorage force. The simulation indicates the scheme of anti-pile and anchor cable with the controllable deformation is appropriate for the treatment of Pingle interchange bedding slope. According to the construction of the treatment of Pingle, the key processes and monitoring measures in this scheme are feasible. In addition, the deformation of this slope has been effectively tackled, and the general slope of Pingle is in a stable state at present.