横向激励下隧道-竖井节点地震响应研究
张敬华1,2,袁 勇2,孙 清1,曲雅菲3

(1. 西安交通大学 土木工程系,陕西 西安 710049; 2. 同济大学 土木工程防灾国家重点实验室,上海 200092; 3. 西安交通大学 人居环境与建筑工程学院,陕西 西安 710049)

隧道; 竖井; 地震响应; 振动台试验; 拟静力模型

Seismic responses of tunnel-shaft junction under transverse excitations
ZHANG Jinghua1,2, YUAN Yong2, SUN Qing1, QU Yafei3

(1.Department of Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China; 2.State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China; 3.School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049,China)

tunnel; shaft; seismic responses, shaking table test; pseudo-static model

DOI: 10.15986/j.1006-7930.2023.02.003

备注

隧道-竖井节点是地下空间网络的重要节点,也是其抗震薄弱环节。由结构突变造成的土-结构动力相互作用不均匀会导致隧道与竖井产生显著的差动响应。本文依托典型软土道路隧道工程,以隧道-竖井节点为试验对象,依据动力相似原理完成了以土-结构相对刚度为控制因素的模型设计,并开展了横向激励下隧道-竖井节点振动台模型试验。试验中测量了结构加速度响应和结构变形两类数据。通过对比加速度峰值和相关系数,对隧道与竖井间的地震差动响应进行了定量描述,并分析了由此引发的隧道纵向变形模式。在此基础上,基于梁-弹簧模型,提出了隧道-竖井节点地震响应拟静力简化分析模型,并推导了隧道变形的拟静力解析计算方法。经振动台试验结果验证,该拟静力简化分析模型可较好地预测隧道纵向变形,并以闭式解的形式,直接建立了隧道纵向变形与隧道-竖井相对位移的定量关系。
Tunnel-shaft junction is an integral part of the underground network. It is also among the underground structures most vulnerable to seismic impacts. The non-uniform soil-structure interactions stemming from the abrupt structural change are likely to cause discrepant responses between the shaft and the tunnel. Based on the engineering background of a typical highway tunnel in soft soil, a shaking tablet test was conducted on the shaft-tunnel junction. Following the dynamic similitude principles, the soil-structure relative stiffness was chosen as the controlling factor in the design of the model system. During the test, the shaft-tunnel junction was subject to transverse excitations, and accelerations and deformations of the model were recorded. The discrepant responses between the shaft and the tunnel were quantified through comparisons of their acceleration responses. The longitudinal deformation mode of the tunnel was thus analyzed. Hence, based on the beam-spring model, a pseudo-static model was proposed for the shaft-tunnel junction, and a pseudo-static analytical solution was therefore derived. As validated by the test results, the proposed pseudo-static model could predict longitudinal deformations of the tunnel under transverse excitations with reasonable accuracy. Moreover, it directly established a quantified relation between the longitudinal deformation of the tunnel and the tunnel-shaft relative displacement.