小湾水电工程坝前2^#山梁高边坡稳定性评价  

Study on stability of 2^# high rock slope in front of the dam in Xiaowan hydropower project by using 3D numerical simulation

作　　者：张敏[1] 黄润秋[1] 史新鹏[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《湖南科技大学学报（自然科学版）》2009年第1期53-57,共5页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金雅砻江水电开发联合研究基金重点项目(50539050)

摘　　要：小湾电站工程2#山梁位于坝前左岸,其中饮水沟堆积体下部分布于自饮水沟沟心到2#梁山脊一带,前缘高程1160m,上部分分布于龙台路一带的缓坡.拱肩槽的开挖,因其斜切2#梁形成上宽下窄的"倒楔形岩体",其稳定性将关系到饮水沟堆积体的稳定性及大坝的建设与运行.2#山梁的岩体结构特征及其边坡开挖过程中产生的变形破坏现象表明,其变形破坏特点为边坡开挖产生卸荷回弹,岩体应力进行调整,结构面的不利组合使得浅表层强卸荷带岩体产生向临空面的变形破坏,坡体内不存在控制边坡变形的统一的、不利的结构面.在此基础上,运用数值模拟的手段,对2#山梁在开挖及蓄水工况下的稳定性进行了分析,结果表明,开挖边坡在经过初期的调整后,其变形将逐渐趋于收敛稳定,不会进入累进性整体破坏阶段;蓄水工况下,边坡的变形虽然有所增加,但增加幅度不大,在采取适当的措施进行局部变形的控制后,最终仍将趋于收敛稳定.图7,表1,参7.2^# high rock slope is located in the left band of the dam in Xiaowan Hydropower Project, and the lower reaches of YinShuiGou deposit rock is distributed in YinShui gully center to its chine, the front edge elevation of which is 1 160 meters, the upper sectors is distributed in/he ramp of the TianTai road. The excavation of the spandrel groove obhquely incises the 2^# rock slope, which forms an inverse cuneiform-like rock masses, looking like wide in the upper and narrow in the lower, the stabihty of which is important to the stability of YinShuiGou deposit rock and the construction and operation of this project. Detailed analyses of the structure character of rock mass and the deformation-failure phenomena during the slope excavation show that the rock mass near slope rebounds toward the free surface due to the stress relief, which results in the deformation and failure of the strong unloading rock masses under the disadvantageous combination of structural planes; there is no unified-disadvantageous structure planes controlling the slope deformation inside of the slope. Based on this, study on stability of this slope is done by using 3D numerical simulation under the excavation and sluice situation. Results indicate that slope deformation will gradually converge and stabilize after the gorge stress field adjustment. Under the sluice situation, although the displacement value is greater, the deformation will tent to be stable after taking appropriate measures to the local rock masses.

关 键 词：拱肩槽 岩体结构特征 卸荷回弹 数值模拟 

分 类 号：P642.116[天文地球—工程地质学]