【摘要】 基于现有研究成果,将增量动力分析引入大型地下洞室群地震动力稳定性评价领域,形成大型地下洞室群的性能化地震动力稳定性评价方法。首先讨论基于PEER-NGA数据库的强震记录选取方法,根据具体工程的地震地质特性针对性地搜索合适的强震记录,为开展增量动力分析提供最优的输入地震动。然后讨论适用于大型地下洞室群的结构损伤性能参数、地震强度因子的选取,为增量动力分析提供合适的地震强度指标和抗震性能表征。继而立足于现有规范,形成了适用于大型地下洞室群性能化地震动力稳定性评估的2级地震动水平和2级抗震性能水平。最后采用本文的方法及步骤对大岗山水电工程地下洞室群进行地震动力稳定性评估。结果表明,该方法较好地考虑了地震动的随机性,给出洞室群的抗震性能,并可进一步对地震动力稳定性进行概率分析,为大型地下洞室群地震动力灾变失稳提供准则。更多还原

【Abstract】 Based on existing research results and incremental dynamic analysis(IDA),a performance-based seismic stability assessment approach specified for large underground cavern group is proposed.On the basis of this procedure,the selection of ground motions via PEER-NGA database,which provides the optimal input seismic ground motion for IDA,is discussed;and the selections of intensity measure and damage measure specified for large underground cavern group are processed,thereby providing appropriate earthquake intensity index and seismic performance characterization for IDA.The performance objectives are then classified based on the electricity generating duty of the cavern as serviceability and safety.Reference earthquake motions are specified for each objective as operating basis earthquake and safety evaluation earthquake.The underground cavern group of the Dagangshan hydropower project is taken as a demonstrating case.The results show that randomness of ground motion is well premeditated in this approach;and aseismic performances of cavern group can be given with this approach.Followed by probabilistic results of seismic vulnerability,this approach can provide criterion on the seismic stability assessment of large underground cavern group.更多还原