不同方向地震激励下软岩桥隧搭接段动力响应研究  

Dynamic responses of bridge-tunnel approaching parts under different seismic excitation directions in soft surrounding rock

作　　者：孙广臣[1,2] 谢佳佑 何山 傅鹤林[1] 江学良[2] 郑亮 SUN Guang-chen;XIE Jia-you;HE Shan;FU He-lin;JIANG Xue-liang;ZHENG Liang(School of Civil Engineering,Central South University,Changsha,Hunan 410075,China;College of Civil Engineering,Central South University of Forestry and Technology,Changsha,Hunan 410007,China;College of Architecture Engineering,Hunan Communication Polytechnic,Changsha,Hunan 410004,China;National Engineering Laboratory for Construction Technology of High Speed Railway,Central South University,Changsha,Hunan 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南林业科技大学土木工程学院,湖南长沙410007 [3]湖南交通职业技术学院建筑工程学院,湖南长沙410004 [4]中南大学高速铁路建造技术国家工程实验室,湖南长沙410075

出　　处：《岩土力学》2019年第3期893-902,912,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51408617);国家自然科学基金项目(No.51578550;No.51204215);中南大学博士后科研启动基金(No.169720);中南林业科技大学引进高层次人才科研启动基金项目(No.1040331)~~

摘　　要：在遭遇强烈地震时,复杂地形和地质条件下高速铁路桥隧搭接段是容易出现严重损伤或破坏的一类复杂连接工程组合体。但是,目前国内外对于统筹考虑桥-隧-岩这一复杂系统内不同结构、部位之间相互作用的在强烈地震作用下的震害机制与动力响应的研究仍不多见。为此,设计并完成了多组基于大型振动台的不同方向地震激励下的模型试验,分析了软岩桥隧搭接段的动力响应特点及激励方向的影响机制。试验结果表明,强烈地震作用对桥-隧-软岩系统的安全与整体稳定非常不利,且隧道洞口及桥梁端部的加速度、位移、应变等地震响应数值大小及变化规律在不同方向地震激励下有显著的差异性。隧道扩大段拱顶和拱脚、标准段拱脚以及桥梁端部、桥台顶部、洞顶土体等部位地震响应较大,应予以加强或特殊处理。研究结果可以为软岩条件下桥隧相连结构抗震设计与地震响应分析提供一定参考。The high-speed railway bridge and tunnel junction is considered as a complex engineering project. At the event of strong earthquake, serious damage or even completely destruction of this junction would occur under complex topography or poor geological conditions. However, there is limited information on the seismic damage mechanism and dynamic response of interactions between different structures and locations in the complex bridge-tunnel-rock system. Therefore, large-scale shaking table tests were carried out on soft surrounding rock. The seismic dynamic response characteristics of the bridge-tunnel junction and the influence mechanism of the excitation direction were analyzed as well. The experimental results showed that the effect of strong earthquake is detrimental to the safety and stability of the bridge-tunnel-soft rock system. There were significant differences on variation laws of dynamical responses such as the acceleration, displacement and strain parts at the tunnel entrance and the end of the bridge under different earthquake excitations. Relatively large values of seismic responses could occur at the overlapped parts or sections of the bridge-tunnel junction(arch waist and arch foot at lining expansion section, arch foot at the tunnel standard section, the bridge beam end and top of the abutment inside the tunnel portal, and the soil above the cave roof etc.), which required special reinforcement or treatment. The obtained results provide useful references for the further study of structural seismic design and seismic response analysis of bridge-tunnel connecting structures in soft surrounding rock conditions.

关 键 词：软岩 桥隧搭接段 大型振动台 不同激震方向 地震响应 

分 类 号：TU317[建筑科学—结构工程] U448.14[建筑科学—桥梁与隧道工程]