海底隧道施工过程中围岩稳定性的流固耦合分析  

Coupled Fluid-Solid Analysis of the Surrounding Rock Stability of the Subsea Tunnel during Construction Process

作　　者：李鹏飞[1] 张顶立[1] 李兵[1] 房倩[1] 孙锋[1] 

机构地区：[1]北京交通大学隧道及地下工程教育部工程研究中心,北京100044

出　　处：《中国铁道科学》2010年第3期35-41,共7页China Railway Science

基　　金：国家自然科学基金资助项目(50778011);国家"八六三"计划项目(2006AA11Z119);北京交通大学优秀博士生科技创新基金资助项目(141072522)

摘　　要：以厦门翔安海底隧道为工程背景,基于流固耦合理论,对穿越海域风化槽段施工过程中的围岩稳定性进行数值计算,研究不同施工阶段隧道围岩位移场和渗流场分布规律及支护结构的受力特征。研究结果表明:地下水的渗流作用对海底隧道的围岩变形影响很大,引起较大范围的海床沉降;超前导洞开挖对围岩渗流场的影响作用最为直接和明显,且由渗流引起的海底隧道围岩变形在向上传递过程中折减较小;海底隧道洞周变形和海床沉降主要集中在两侧导洞下部和中部核心土上部开挖过程中;海水水位变化对海床沉降、拱顶沉降、拱底回弹量及围岩塑性区分布范围均有一定影响;注浆圈加固效果直接影响海底隧道开挖后围岩位移场和渗流场的分布,且注浆加固区厚度及渗透系数存在1个经济合理值;海底隧道拱腰横向支撑节点的应力集中较大,出现较大的塑性破坏区;海底隧道支护结构受力分为3个阶段,且拱脚、横支撑支点处受力较大。Taking Xiamen Xiang＇an subsea tunnel as the project background,based on the coupled fluid-solid theory,numerical analysis was made to study the stability of the surrounding rock during tunneling through the weathered slot under the sea.The distribution principle of the displacement field and the seepage field of the surrounding rock,as well as the mechanical characteristics of the lining structure were studied in various construction stages of subsea tunnel.The results indicate that the seepage of the groundwater has great influence on the deformation of surrounding rock,causing a larger range of sea-bed subsidence.The excavation of the pilot heading has the most direct and obvious influence on the seepage field of the surrounding rock,and the attenuation of surrounding rock deformation induced by the seepage is smaller in its transfer process from the surrounding rock to sea-bed.The surrounding rock deformation and sea-bed subsidence mainly concentrate on the excavation of both sides of the pilot heading and the upper rock of the central core.The changes of the sea level have certain influence on the sea-bed subsidence,vault settlement,invert spring back and the plastic zone of the surrounding rock.The influence of the grouting circle on the displacement field and seepage field of the surrounding rock is significant,and an economical and rational value exists for the thickness of the grouting circle and the permeability coefficient.The stress concentration in the lateral support nodes of the lumbar arch is greater,and larger plastic failure zone appears consequently.The mechanical characteristics of the lining structure in the subsea tunnel can be divided into 3 stages,and larger force exists in the arch foot and the lateral support nodes of the lumbar arch.

关 键 词：海底隧道 风化槽 围岩稳定性 围岩变形 海床沉降 流固耦合理论 注浆加固圈 支护 

分 类 号：U459.5[建筑科学—桥梁与隧道工程] U451.2[交通运输工程—道路与铁道工程]