SV波不同角度入射下近接双隧道的地震响应分析  

Seismic response analysis on adjacent double tunnel at different incident angles of SV waves

作　　者：孙纬宇 严松宏[1,3] 汪精河 梁庆国[1,2] Sun Weiyu;Yan Songhong;Wang Jinghe;Liang Qingguo(School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;Key Laboratory of Road and Bridge and Underground Engineering of Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China;Engineering Laboratory of Mechanics Application of Railway Transportation of Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]兰州交通大学甘肃省道路桥梁与地下工程重点实验室,兰州730070 [3]兰州交通大学甘肃省轨道交通力学应用工程实验室,兰州730070

出　　处：《东南大学学报（自然科学版）》2019年第5期956-963,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51268030,41562013);兰州交通大学青年科学基金资助项目(2017020);兰州交通大学甘肃省道路桥梁与地下工程重点实验室开放基金资助项目(1200110206-2)

摘　　要：为了研究地震波入射角度和洞距对近接隧道动力响应特征的影响,采用黏弹性边界结合等效荷载的输入方法,实现了平面SV波斜入射的地震动输入,研究了不同SV波入射角度和隧道洞距时隧道衬砌应力的分布特征.结果表明:地震波入射角度对隧道衬砌应力的分布有较大影响.当地震波垂直入射时,隧道衬砌应力呈蝴蝶状(X状)的对称分布,在横断面内沿共轭45°方向受力较大;当地震波倾斜入射时,隧道衬砌的应力呈不对称状分布,在拱顶-30°~30°和仰拱120°~255°范围内受力较大.从隧道衬砌受力和震害情况来看,隧道拱部和仰拱部位在地震时容易发生破坏,在隧道抗震设计中应予以考虑.隧道衬砌应力随地震波入射角度的增大而增大,随洞距的增大而减小,且入射角度对隧道衬砌受力的影响较洞距的影响要大,在极震区隧道抗震设计要考虑地震波入射角度的影响.地震波倾斜入射时,两隧道间的合理净距为洞径的4倍.To study the impact of incident angle of seismic waves and tunnel distances on the dynamic response characteristics of adjacent double tunnels, a input method for the visco-elastic artificial boundary combined with the equivalent load was adopted to realize the ground motion input of the oblique incident of SV waves and the stress distribution characteristics of tunnel lining at different incident angles of SV waves and tunnel distances were studied. The results show that the incident angle of seismic wave has a great influence on the stress distribution of tunnel lining. It is symmetrical in the butterfly shape (X shape) when seismic waves incident vertically, and the force along the direction of conjugate 45° is larger than the other directions in the cross section. And it is asymmetrical when seismic waves incident obliquely and the force along the direction of (-30° to 30°) and inverted arch (120° to 255°) is larger. According to the stress in tunnel and the earthquake damage of tunnel lining, the arch and inverted arch parts are easy to be damaged during earthquakes, it should be considered in seismic design of the tunnel. The stresses in tunnel lining increase with the increase of the incident angle, and decrease with the increase of the tunnel distance. The incident angle has a great influence than tunnel distance for the stresses in tunnel lining. The seismic design of tunnels should consider the influence of incident angels on mesoseismal area. The reasonable distance between the adjacent double tunnels is 4 times of the diameter of the tunnel when seismic waves incident obliquely.

关 键 词：黏弹性边界 SV波 双隧道 洞距 地震响应 

分 类 号：TU435[建筑科学—岩土工程]