摘要
深埋海底隧道经常处于高水压工况,地下水渗流对隧道围岩及衬砌结构安全性有较大影响.本文提出了一种含衬砌深埋海底隧道力学模型,研究了海底隧道服役阶段地下水渗流对围岩及衬砌结构稳定性的影响机理.应用保角映射方法将包含海水与围岩弹性区的半无限域映射成圆环域,根据渗流边界条件建立了各界面间极坐标下的渗流方程,得到了海底隧道渗流场解析解.将渗流场以体积力形式作用到应力场中,根据应力边界条件建立了应力平衡方程,基于考虑中间主应力影响的Drucker-Prager(D-P)准则,得到了渗流效应影响下围岩与衬砌结构的弹塑性解析解.以深圳妈湾跨海通道工程为例,将解析解与有限元数值解进行了对比,验证了本文理论解的准确性,研究了渗流效应对隧道围岩与衬砌结构应力场的影响规律.最后,分析了海水深度与内水水头对塑性区半径的影响.研究结果表明:渗流效应对围岩与衬砌结构中的环向应力影响显著,径向应力随ρ增大呈非线性增长;随着海水加深,隧道承受水压不断加大,围岩塑性区范围显著增大;增加内水水头可以有效限制围岩塑性区发展,初始阶段限制效果明显,后续增加内水水头限制效果逐渐减弱.
Deep-buried subsea tunnels are often under high water pressure condition and therefore groundwater seepage exerts a great impact on the surrounding rock and lining structure safety.In this paper,a mechanical model of deepburied subsea tunnel with lining is proposed to study the influence mechanism of groundwater seepage on the surrounding rock and lining structure stability during the service stage of subsea tunnel.Firstly,a conformal mapping method is adopted to map the semi-infinite domain which includes seawater and surrounding rock elastic zone into an annular domain,and the seepage equation in polar coordinates between interfaces is established according to the seepage boundary conditions.Thus,the analytical solution of the seepage field of the subsea tunnel is obtained.Secondly,the seepage field is applied to the stress field in the form of volume force,the stress balance equation is established according to the stress boundary conditions,and based on the Drucker-Prager(D-P)criterion which takes account of the effect of the intermediate principal stress,an elastoplastic analytical solution is derived for the surrounding rock and lining structure under the influence of seepage effect.Finally,taking Shenzhen Mawan Sea-Crossing Passage as an engineering example,the analytical solution is compared with the finite element numerical solution,which verifies the accuracy of the theoretical solution in this paper,the influence law of seepage effect on the stress field of tunnel surrounding rock and lining structure is studied,and the factors influencing the radius of surrounding rock plastic zone are analyzed.The results show that:the seepage effect has a significant influence on the hoop stress in surrounding rock and lining structure,and the radial stress increases nonlinearly with the increase ofρ.As the seawater goes deeper,the water pressure on tunnel continues to increase,and the surrounding rock plastic zone increases significantly.An increase in the internal water head can effectively limit the development of the surrounding rock plastic zone,with the initial limiting effect being obvious while the subsequent effect being gradually weakened.
作者
金波
胡明
方棋洪
Jin Bo;Hu Ming;Fang Qihong(Key Laboratory for Damage Diagnosis of Engineering Structures of Hunan Province,College of Civil Engineering,Hunan University,Changsha 410082,China;Hunan Huda Construction Supervision Co.,Ltd.,Changsha 410082,China;College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)
出处
《力学学报》
EI
CAS
CSCD
北大核心
2022年第5期1322-1330,共9页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(11772122)。
作者简介
金波,副教授,主要研究方向:结构优化设计、工程结构力学.E-mail:jinbo@hnu.edu.cn。
