平面SV波垂直入射下浅埋双圆隧道复合衬砌解析解及减震力学机理分析  

Dynamic stress concentration and damping mechanism of twin cylindrical composite-lined tunnels subjected to vertical incident plane SV waves

作　　者：高波[1] 王帅帅[1,2] 申玉生 范凯祥[1] 

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]中交第二公路工程局有限公司,陕西西安710065

出　　处：《岩土工程学报》2018年第2期321-328,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51678501,51778540,51778539,51178398);国家重点研发计划项目(2016YFB1200401)

摘　　要：基于波函数展开法,给出了平面SV波入射下地下半空间弹性介质中圆形双洞复合式衬砌洞室动应力集中系数解析解,建立了小净距隧道减震层力学模型,并深入研究了低频SV波入射下洞室间距和减震层对衬砌动应力集中的影响。分析结果表明：洞室间距对衬砌的动应力有显著影响,随着洞室之间距离增大,左右洞室衬砌动应力集中系数降低;当洞室间距小于4倍洞室直径时,必须考虑双洞的相互影响;洞室中间部分围岩动应力集中系数较大;在围岩和衬砌间设置减震层,由于减震层刚度低,可以减小围岩对隧道的径向作用力,减震层可以降低衬砌动应力20%左右,但同时围岩切向动应力增大。A series of solutions are presented for the dynamic stress concentration factor of the underground twin cylindrical tunnels with composite liners and buffer layers in a half elastic space subjected to vertically incident plane SV waves based on the Fourier-Bessel expansion method, and the mechanical model for the tunnels with small clear distance with soft layer is established. The influences of the factors such as the distance between the tunnels and the damping layer are investigated. It is shown that the distance between the tunnels plays an important role in the dynamic stress concentration factor of the composite-linned tunnels, and the dynamic stress of the liners decreases when the distance of the tunnels increases. The interaction of the two tunnels must be considered when the distance between the centers of the cavities is less than 4 times the diameter of the chamber. The dynamic stress concentration factor of the surrounding rock in the middle part between the tunnels is larger than that at the other parts. With the low shear modulus of the damping layer, the normal force between the wall rock and the liner is weakened, then the dynamic stress of the liners decreases by 20% with the buffer layers set between the surrounding rock and the liner, while the tangential dynamic stress of the surrounding rock increases.

关 键 词：平面SV波 圆形隧洞 减震层 衬砌 动应力集中系数 

分 类 号：TU43[建筑科学—岩土工程]