摘要
西藏扎拉水电站枢纽区边坡倾倒变形现象普遍发生,对工程的安全建设和运行带来隐患。对此,采用三维非连续分析方法,对大坝右岸倾倒边坡开挖失稳模式及加固措施开展研究。结果表明:(1)大坝右岸倾倒边坡开挖后,潜在失稳区域主要集中在开挖边坡上部钙质板岩极强倾倒区岩体内,后缘主要发生边坡上部崩坡积层破坏,失稳岩体沿着钙质板岩极强倾倒变形区和弱倾倒变形区分界面滑动,呈现典型的“滑移-拉裂”型变形破坏模式;(2)锚索+锚杆的联合支护措施可有效限制开挖施工期间大坝右岸倾倒边坡上部钙质板岩极强倾倒区岩体的变形。采取支护措施后,大坝右岸倾倒边坡各工况下的安全系数均可满足规范要求。
The phenomenon of toppling slope in Xizang Zhala Hydropower Station is widespread,which posed hid-den dangers to the safety construction and operation of the project.In this regard,a three-dimensional discontinu-ous analysis method was adopted to study the instability mode and reinforcement measures of the right bank dumping slope after excavation.The results showed that:After the excavation of the right bank toppling slope,the poten-tial instability area was mainly concentrated in the extremely strong toppling area of calcareous slate in the upper part of the excavation slope,and at the rear edge,it was mainly damaged by the colluvial layer in the upper part of the slope.The unstable rock mass slides along the interface between the extremely strong and weak toppling deform-ation zones of calcareous slate,presenting a typical"slip-tensile fracture"deformation and failure mode.②The combined support measures of anchor cables and anchor rods can effectively limit the deformation of the rock mass in the extremely strong dumping area of the upper calcareous slate during the excavation and construction period of the right bank toppling slope.After taking support measures,the safety factors of right bank toppling slope under va-rious working conditions can meet the requirements of the specifications.
作者
刘登学
陈兴
徐果
黄书岭
张雨霆
LIU Dengxue;CHEN Xing;XU Guo;HUANG Shuling;ZHANG Yuting(Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China;Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430010 China;National Dam Safety Research Center,Wuhan 430010,China)
出处
《水利水电快报》
2024年第6期43-48,共6页
Express Water Resources & Hydropower Information
基金
长江勘测规划设计研究有限责任公司自主创新项目(CX2022S046)。
关键词
倾倒边坡
破坏模式
边坡加固
扎拉水电站
toppling slope
instability mode
slope reinforcement
Zhala Hydropower Station
