基于FLAC3D的层间错动带对大型地下洞室地震响应影响分析--以白鹤滩水电站为例  

Analysis of bedding fault zone on seismic dynamic response of large underground cavern based on FLAC3D:a case of Baihetan Hydropower Station

作　　者：杨继华 YANG Jihua(Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,China)

机构地区：[1]黄河勘测规划设计研究院有限公司,河南郑州450003

出　　处：《水利水电快报》2023年第3期39-45,共7页Express Water Resources & Hydropower Information

基　　金：黄河勘测规划设计研究院有限公司自主研究开发项目(2018-ky10)。

摘　　要：为揭示大型地下洞室群地震响应机制,以西南地区白鹤滩水电站大型地下厂房洞室群为研究对象,运用有限差分数值模拟软件FLAC3D,建立了13号机组剖面数值分析模型,基于弹塑性本构关系,采用动力时程分析方法,研究了地下厂房洞室群在有、无层间错动带条件下围岩地震响应的加速度、变形、应力、塑性区等特征。结果表明:①有层间错动带条件相比无层间错动带条件,洞室群围岩的响应加速度峰值和围岩变形值分别增加了2%~34%和18%~63%;②层间错动带对震后围岩应力状态有一定影响,与无层间错动带条件相比,有层间错动带条件下的围岩拉应力区范围明显增大;③在有层间错动条件下,由开挖和地震产生的塑性区面积分别为8684m^(2)和975m^(2),均大于无层间错动带条件的7103m^(2)和888m^(2)。在地下洞室的抗震设计中,层间错动带对大型地下洞室地震响应的影响不可忽视。In order to study the seismic dynamic response mechanism of large underground cavern,a large underground powerhouse cavern group of Baihetan Hydropower Station in Southwest China was taken as the research object,and the finite difference program FLAC3D was used to modeling the section of unit 13.Based on the elastic-plastic constitutive relation,the surrounding rock seismic response characteristics such as acceleration,deformation,stress and plastic zones of underground powerhouse caverns with and without bedding fault zone were studied by dynamic time-history analysis method.The results showed that:①the peak value and the deformation value of the response acceleration of the surrounding rock under the condition of bedding fault zone were increased by 2%~34%and 18%~63%respectively,compared with that without bedding fault zone;②bedding fault zone had a certain influence on the stress of surrounding rock,and the range of tensile stress zone of surrounding rock with bedding fault zone was larger than that without bedding fault zone;③under the condition of bedding fault zone,the area of plastic zone caused by excavation and seismic was 8684m^(2) and 975m^(2) respectively,which were larger than 7103m^(2) and 888m^(2) under the condition of no bedding fault zone.The influence of bedding fault zone on seismic dynamic response of large underground cavern cannot be ignored in the seismic design for underground cavern.

关 键 词：地下洞室 层间错动带 地震响应 FLAC3D 动力时程分析 白鹤滩水电站 

分 类 号：TV731.6[水利工程—水利水电工程] TV223.1