CCS水电站地下厂房施工过程中围岩稳定性分析  

Analysis of Surrounding Rock Stability in Construction Process for Underground Powerhouse of CCS Hydropower Station

作　　者：齐三红[1] 杨继华[1] 杨风威[1] 娄国川[1] 

机构地区：[1]黄河勘测规划设计有限公司,河南郑州450003

出　　处：《水电能源科学》2016年第12期145-149,共5页Water Resources and Power

摘　　要：CCS水电站地下厂房由主厂房和主变室组成,为超大断面地下洞室,其开挖过程中围岩应力、变形等特征决定着地下厂房施工和运营过程中的安全性和可靠性。通过分析工程地质条件,选取#8机组剖面建立地质概化模型,采用有限元程序Phase 2建立数值分析模型,基于弹塑性本构关系对施工开挖和支护进行数值模拟,研究开挖过程中围岩变形场、应力场及塑性区的分布及变化特征。结果表明,洞室顶拱的变形和应力集中主要产生在当层开挖,后续开挖对其影响较小,围岩趋于稳定;主厂房、主变室洞周岩体均呈现出向岩体内延伸的塑性区,塑性区岩体的破坏以剪切破坏为主;锚杆和喷混凝土支护对围岩的变形影响较小,对围岩的应力集中、拉应力区和塑性区有一定程度的改善。该研究结论和方法为地下厂房的施工开挖和支护设计提供了参考。The underground powerhouse system of CCS hydropower station is composed of main powerhouse and main transformer chamber,which is super-large cross-section underground cavern.The safety and reliability of underground powerhouse during construction and operation are determined by the stress and deformation characteristics in excavation process.The No.8unit cross section was selected for a subject to establish a generalized geologic model by studying engineering geological condition.The numerical model was built by the finite element program of Phase 2.Construction excavation and support were simulated based on elastic-plastic constitutive relations.The distribution and variation characteristics of deformation field,stress field and plastic zone were studied in excavation process.The results show that the deformation and stress at the arch generated on the current stage mainly,which was affected slightly in next excavation;the surrounding rock had the trend of stability.The plastic zone which stretched in rock mass appeared at main powerhouse and main transformer surrounding rock and the rock failure in plastic zone was mainly shear type.The support of bolts and shotcrete had slight impact on the surrounding rock deformation,but it made a certain degree of improvement to stress concentration,tensile stress and plastic zones.The study contents and methods can provide a reference for excavation and support design of underground powerhouse.

关 键 词：水电站 地下厂房 施工过程 数值模拟 围岩稳定性 

分 类 号：TV222.2[水利工程—水工结构工程]