摘要
地震作用下隧道结构动力响应与地层介质特性密切相关,目前长隧道建设量大、面广,且长度可达数公里甚至数十公里,隧道沿线地层介质参数具有显著的空间变异性和相关性,但现有隧道纵向抗震设计中地层参数仅采用有限钻孔数据,尚未考虑钻孔之间地层的随机场特性。基于随机场理论建立描述地层参数空间变异性和相关性的随机场模型,采用协方差矩阵分解法生成地层参数随机场分布,并将其导入表征地层-结构动力相互作用的三维有限元简化模型中,从而开展考虑地层参数随机场影响的隧道纵向地震响应多工况模拟,重点研究不同地层水平相关距离、不同地层变异系数及不同地层均值变化对隧道结构动力响应的影响规律。结果表明:相关距离、变异系数及均值变化均会对结构地震响应产生显著影响,结构响应与水平相关距离及均值变化负相关,与变异系数变化正相关,且地层变异系数对结构响应的影响显著大于相关距离;与不考虑随机性的均值场相比,考虑随机场可使隧道结构弯矩响应幅值放大约80%,且在0.005的置信水平下均值场分析将导致结构设计偏于不安全。
Seismic responses of tunnel structures are closely related to the surrounding strata properties.Currently,long tunnel construction develops fast and the tunnel length may reach up to several or even scores of kilometers.The strata parameters along the tunnel have significant spatial variability and correlation.However,the strata data used in the longitudinal seismic design of the tunnel was based on limited borehole data,and thus the random field characteristics of strata parameters between the boreholes have not been considered yet,or at least not well addressed.In this paper,a stochastic field model describing spatial variability and correlation of strata parameters was established based on the random field theory,and the covariance matrix decomposition method was used to generate random field distribution of strata parameters,which were employed into the simplified three-dimensional finite element model to characterize the dynamic interaction between stratum and structure.A series of simulation cases of tunnel longitudinal seismic response considering the influence of random field of stratum parameters were carried out to study the influence of horizontal correlation distance,variation coefficient and mean value of stratum on the seismic response of tunnel structure.Results indicated that!the correlation distance,variation coefficient and mean value all had a significant impact on the seismic response of the structure,and the change of horizontal correlation distance and mean value had a negative influence on the seismic response of the structure while the coefficient of variation had a positive influence.The influence of variation coefficient on the structural response was significantly greater than correlation distance;compared with the mean field without consideration of the randomness,the random field could significantly amplify the moment response amplitude of the tunnel structure by about 80%,and the mean field results would lead to unsafe design under the confidence level of 0.005.
作者
禹海涛
何爽
李攀
李帅
陈峰军
王新新
YU Haitao;HE Shuang;LI Pan;LI Shuai;CHEN Fengjun;WANG Xinxin(Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;School of Rail Transportation,Soochow University,Suzhou 215131,Jiangsu,China;China Machinery Industry Information Institute,Beijing 100037,China;Shanghai Construction Group Co.,Ltd.,Shanghai 200080,China)
出处
《隧道与地下工程灾害防治》
2020年第3期58-66,共9页
Hazard Control in Tunnelling and Underground Engineering
基金
国家重点研发计划资助项目(2018YFC0809600,2018YFC0809602,2018YFC1504305,2017YFC1500703)
国家自然科学基金资助项目(41922059,51978431,51678438)
上海市科委重点课题资助项目(18DZ1205106)
中央高校基本科研业务费专项资金资助
关键词
隧道
随机场
纵向抗震
有限元模型
置信度分析
tunnel
random field
longitudinal seismic
finite element model
confidence analysis
