某拱坝右岸拱肩槽开挖边坡锚固仿真与优化研究

Numerical Simulation on Reinforcement Measures and Optimization Analysis for Excavation Slope in Right Abutment Trough of an Arch Dam

首先基于一次宏观反演的初始应力场进行二次精细模拟得到了某拱坝坝区局部模型的初始地应力场。接着基于加锚节理岩体流变模型,应用自主开发的三维弹粘塑性有限单元程序模拟了该初始地应力场作用下该拱坝右岸拱肩槽岩石高边坡开挖过程预应力锚索、系统锚杆等锚固件的支护作用。分析了现行锚固方案与锚固进度下边坡岩体的位移、应力和点安全系数等分布规律,最后在此基础上对该锚固方案和锚固进度进行了优化,确保了该边坡的稳定与安全。

Firstly,the initial geostress field of the arch dam area is obtained by the second-stage refinement simulation with the initial geostress field of the first-stage back analysis.And then,based on the model of reinforced jointed rock masses which can be used to simulate anchoring effects of pre-stress cables and systematic bolts,the effects of reinforcement measures for the excavation slope in the right abutment trough of Xiluodu arch dam are simulated by the self-developed 3D elasto-viscoplastic finite element method（FEM） analysis program under the initial geostress field.The distribution patterns of stress,displacement and safety factor of the rock slope are analyzed for current anchoring schemes and anchoring schedules.Finally,the current reinforcement schemes and anchoring schedules are optimized to ensure the stability and safety of the slope on the basis of the above analysis.