Optimization Analysis on Reinforcements for Excavation Slope in Left Abutment Trough of Xiluodu Arch Dam

摘要

An excavation slope in left abutment trough of Xiluodu arch dam has 380 meters or so. In order to ensure safety of the excavation slope, the designed excavation and reinforcement process of the slope is simulated systematically with self-developed 3D elasto-viscoplastic finite element method (FEM) analysis program based on the model of reinforced jointed rock masses. Distribution patterns of displacements, stresses and point safety factors of the rock slope and reinforcement effects under tectonic initial geostress field are analyzed and the slope stability is evaluated in each excavation step. The simulation results show that displacements of the excavated slope between 470 meter and 400 meter in elevation are relatively bigger and its yield zone extends deeper into the mountain body in the designed excavation and reinforcement scheme. Supplementary reinforcements with some pre-stress cables are suggested for strengthening the excavation slope from 470 meter to 400 meter in elevation. The numerical simulation results show that the new reinforcements help improve the stability of the excavation slope in left abutment trough and ensure the safety of the slope.