高放废物北山地下实验室硐室群地震动反应特征研究  

Seismic response characteristics of the cavern group of the Beishan underground research laboratory for the geological disposal of high-level radioactive waste

作　　者：云龙 陈苏 傅磊[4] 庄海洋 王驹[1,2] YUN Long;CHEN Su;FU Lei;ZHUANG Hai-Yang;WANG Ju(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste,Beijing 100029,China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100024;Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang,330013,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]国家原子能结构高放废物地质处置创新中心,北京100029 [3]北京工业大学建筑工程学院,北京100024 [4]中国地震局地球物理研究所,北京100081 [5]华东交通大学土木工程学院,江西南昌330013

出　　处：《物探与化探》2024年第6期1519-1529,共11页Geophysical and Geochemical Exploration

基　　金：国防科工局放射性废物处置项目专题“地下实验室场址地壳稳定性分析与评价研究”(FZ2101-6)。

摘　　要：高放废物北山地下实验室紧邻的河西走廊和北祁连地区地震环境复杂、强震多发,而地下实验室作为由三竖井+螺旋斜坡道构成的复杂地下结构,具有明显的大尺度空间分布特征,研究地下实验室地下结构群的地震反应特征,对于后期场址的地壳稳定性评价工作具有重要的工程意义。本文根据地下实验室的设计和已有的围岩物理、力学参数,建立了岩体—地下结构体系精细化三维有限元计算模型,开展了关键断裂对地下实验室近场地震安全性影响研究。结果表明:传统的地震动衰减关系难以考虑近场可能存在的有限断层效应、破裂方向性效应和上盘效应等近场震源效应,采用随机有限断层法可以有效地考虑上述近场地震动特性;目标场址场地类型为花岗岩硬基岩场地,近场发震断裂引起的地震动传到场址的反应谱中高频部分发育明显;因地下实验室的非规则结构引起的地下硐室群地震动反应表现出明显的空间变异性,岩体软化带对应地表峰值加速度富集明显,工程中应规避此区域。本次研究为将来高放废物处置库的选址和场址评价提供了地震安全分析方面的依据。The Hexi Corridor and northern Qilian region,adjacent to the Beishan underground research laboratory(URL)for the geological disposal of high-level radioactive waste,exhibit complex seismic environments characterized by frequent strong earthquakes.The Beishan URL,featuring a complex underground structure consisting of three vertical shafts and a spiral ramp,displays significant large-scale spatial distribution characteristics.Investigating the seismic response characteristics of the underground structure group holds great engineering significance for the subsequent assessment of crustal stability at the site.Based on the design of the URL,along with existing physical and mechanical parameters of surrounding rocks,this study established a fine-scale three-dimensional finite element model of the rock mass-underground structure system.Using this model,this study investigated the impacts of key faults on the near-field seismic safety of the URL.The results indicate that traditional seismic attenuation relationships are difficult to consider near-source effects,such as finite fault effects,fracturing directivity effects,and hanging wall effects.In contrast,the stochastic finite-fault method can effectively consider these near-field ground shaking characteristics.The target site exhibits hard granite bedrock,and the response spectra of the earthquakes induced by near-field seismogenic faults,received at the site,display pronounced high-frequency components.Furthermore,the ground shaking of the underground cavern group,caused by the irregular structure of the URL,presents significant spatial variability,with the rock mass softening zone exhibiting a notable accumulation of peak ground acceleration.This zone should be avoided in engineering applications.This study offers a basis for seismic safety analysis for the future site selection and evaluation of the disposal repositories of high-level radioactive waste.

关 键 词：高放废物处置地下实验室 地震动 断层 地震反应 数值模拟 

分 类 号：O319.56[理学—一般力学与力学基础]