摘要
针对白鹤滩水电站地下洞室群开挖过程围岩稳定问题,基于离散单元法的数值仿真软件3DEC,研究开挖卸荷作用对围岩变形和破坏的影响;引入微震监测技术,对洞室围岩内部微破裂演化实时监测和分析,并将数值模拟结果与微震监测数据对比分析;借助常规位移监测研究围岩宏观变形的时空演化规律,验证数值模拟和微震监测结果的准确性。研究结果表明,围岩损伤与现场施工状态密切相关,同时受各种地质结构影响;数值模拟得到的围岩变形特征与微震监测得到的微震事件聚集规律基本一致,且与常规监测结果对应良好,采用三维离散元数值模拟和微震监测技术相结合的综合研究方法,能够较好地描述围岩在开挖卸荷作用下的力学行为,有效评估洞室围岩的损伤特征和潜在风险区域。
To investigate the stability of the surrounding rock during excavation process of the underground caverns at the Baihetan hydropower station,effects of excavation unloading on the deformation and failure of the surrounding rock using the numerical simulation software 3 DEC based on DEM(discrete element method)are analyzed.The microseismic monitoring technology is introduced to monitor and analyze micro-fracture evolution inside the surrounding rock of the caverns in real time,and the numerical simulation results are compared with the microseismic monitoring data.In order to verify the accuracy of numerical simulation and microseismic monitoring results,the spatiotemporal evolution law of the macro-deformation of the surrounding rock is studied by conventional displacement monitoring.The results show that the damage of surrounding rock is closely related to the on-site construction state and also affected by various geological structures.The deformation characteristics of the surrounding rock obtained by numerical simulation are basically consistent with the aggregation rules of microseismic events obtained by microseismic monitoring,and the results are in good agreement with the conventional monitoring results.The comprehensive research method combining the three-dimensional discrete element numerical simulation and microseismic monitoring technology can better describe the mechanical behavior of the surrounding rock under excavation unloading,and effectively evaluate the damage characteristics and potential risk areas of surrounding rock.
作者
毛浩宇
徐奴文
李彪
樊义林
吴家耀
孟国涛
MAO Hao-yu;XU Nu-wen;LI Biao;FAN Yi-lin;WU Jia-yao;MENG Guo-tao(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu,Sichuan 610065,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China;China Three Gorges Projects Development Co.,Ltd.,Beijing 100038,China;HydroChina Itasca Research and Development Center,Hangzhou,Zhejiang 310014,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第7期2470-2484,共15页
Rock and Soil Mechanics
基金
国家重点研发计划(No.2018YFC1505004,No.2017YFC1501100)
国家自然科学基金(No.51679158)。
关键词
围岩稳定性
离散单元法
数值模拟
开挖卸荷
微震监测
stability of surrounding rock
discrete element method
numerical simulation
excavation unloading
microseismic monitoring
