输水隧道地震响应的多物质ALE数值分析  

Numerical simulation of multi-material ALE method for diversion tunnel seismic response

作　　者：楼云锋[1] 杨颜志[1] 金先龙[1] 

机构地区：[1]上海交通大学机械系统与振动国家重点试验室,上海200240

出　　处：《岩土力学》2014年第7期2095-2102,共8页Rock and Soil Mechanics

基　　金：国家自然基金项目(No.11072150;No.61073088);国家863重大项目课题(No.2012AA01AA307)

摘　　要：为研究浅埋输水隧道内部流体对隧道地震响应的影响,考虑黏弹性人工边界、土壤的非线性、隧道结构刚度有效率及流-固耦合作用,建立了双线隧道-土体-流体相互耦合作用的力学模型。通过刚度折减试验得到衬砌环环向、径向、轴向刚度,进而引入正交各向异性连续材料作为衬砌材料模型。采用基于任意拉格朗日-欧拉(ALE)描述法的流-固耦合方法,对上海某大直径双线输水隧道在流体作用下的地震响应进行了分析。通过与等效密度法对比,验证耦合模型对于处理输水隧道多物质非线性耦合抗震问题的可行性。计算结果表明,在水平方向地震激励下,无论一致激励或是非一致激励流体对隧道地震变形和内力都有较大影响,但对位移影响较小;对于不同隧道内水量,隧道弯矩均集中于衬砌隧道45°交叉斜线位置;相比于一致激励,非一致激励增强隧道地震位移和变形响应是明显的。In order to study the seismic response of shallow diversion tunnel considering sloshing amplitude of the water, an analytical model of tunnel-soil-fluid is proposed taking account of nonlinear material behavior of soil, viscoelastic artificial boundary, the effective rigidity ratios and fluid-solid coupling. Firstly, the hoop, radial and axial structural rigidities of tunnel lining are obtained by numerical rigidity reduction tests. Furthermore, the orthotropic material is used in tunnel lining model. As an application, the seismic responses of a project of large-diameter parallel diversion tunnels, which is one of the key projects in Shanghai, are calculated using the multi-material arbitrary Lagrangian-Eulerian （ALE） method. The equivalent density method is then used to validate the established simulation model. Finally, two seismic input modes, the uniform and nonuniform excitations, are involved in the seismic analyses of the tunnel-soil-fluid system. The numerical results show that under horizontal earthquake excitation the influence of fluid on tunnel＆#39;s displacement is small;however, the influences of fluid on both stress and deformation of the section are great. The tunnel moment are always focused on the position of the tunnel 45° cross-hatched. Comparing with the uniform seismic input, the results show that the nonuniform excitation can remarkably increase both displacement and deformation responses of the tunnel.

关 键 词：输水隧道多物质ALE 有效刚度 流-固耦合 地震响应 

分 类 号：O327[理学—一般力学与力学基础] U459.6[理学—力学]