拉哇水电站右岸边坡群开挖三维数值分析与支护方案优化  

Three-dimensional Numerical Analysis and Reinforcement Optimization of Slope Group Excavation at Right Bank of Lawa Hydropower Station

作　　者：刘东 王庆祥 位伟[2] 姜清辉[2] LIU Dong;WANG Qing-xiang;WEI Wei;JIANG Qing-hui(PowerChina Zhongnan Engineering Corporation Limited,Changsha 410014,China;School of Civil and Architectural Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]中国电建集团中南勘测设计研究院有限公司,湖南长沙410014 [2]武汉大学土木建筑工程学院,湖北武汉430072

出　　处：《水电能源科学》2022年第3期153-157,共5页Water Resources and Power

基　　金：国家自然科学基金项目(42077253,51769014)。

摘　　要：由于拉哇水电站坝址区右岸涉及的工程边坡连片开挖,形成规模较大的边坡群,开挖边坡高陡、规模大、卸荷强烈,对工程的施工和运行安全构成威胁。为此,建立了右岸边坡群开挖三维数值模型,对拉哇右岸边坡群开挖施工过程进行数值模拟。计算结果表明,由于构成大块体边界潜在滑面的深卸荷裂隙在开挖坡面出露,恶化了边坡的整体稳定性条件,最大变形发生在泄洪洞进口三面临空边坡,坡面出露的深卸荷裂隙是需要重点加固部位。在此基础上,结合各部位边坡工程地质条件和原设计加固方案,进一步提出了优化的锚索支护方案。加固模拟结果表明,边坡开挖变形得到抑制,坡面拉应力分布和坡体内部塑性区分布得到明显改善,优化加固方案有效确保了开挖边坡群的整体稳定性。Due to the continuous excavation of the slope located on the right bank of Lawa hydropower station, a large scale slope group is formed. The excavated slopes are of high and steep with large scale and strong unloading, which threaten to the construction and operation safety of the project. The three-dimensional numerical model of right bank slopes was established to simulate the construction process of the slope group excavation. The results show that the deep unloading cracks, which constitute the potential sliding surface of the boundary of the large block, are exposed on the excavated slope surface, and the overall stability of the slope is worsened. The maximum deformation occurs on the slope at the entrance of the spillway tunnel, and the deep unloading cracks exposed on the slope are the key parts that need to be strengthened. Combining with engineering geological properties and the original design scheme of the slopes in different positions, the optimization of anchor cable reinforcement scheme has been proposed. Anchor cable simulation results show that the deformation of slope excavation is decreased, tensile stress distribution on slope surface and plastic zone distribution inside the slopes are obviously improved, and optimization reinforcement scheme ensures the overall stability of slope group excavation effectively.

关 键 词：拉哇水电站 工程边坡 开挖与支护 变形 稳定性 

分 类 号：TV73[水利工程—水利水电工程]