摘要
如何合理估算盾构隧道的地震响应,一直是业界和学界关注的研究热点。相较于横断面地震响应,盾构隧道的纵向地震响应更为复杂。将盾构隧道视为Winkler地基上的Timoshenko梁,考虑轴力影响,包括残余轴力和纵向地震附加轴力,提出纵向与横向地层位移共同作用的理论计算模型,并通过有限差分方法求解盾构隧道纵向地震响应。依托常规6.2m级错缝拼装的盾构隧道进行算例验证,考虑轴力影响使得盾构隧道整体刚度得以提高,内力与变形响应均有所减小;若不考虑轴力影响,则可退化为传统计算方法。进一步地,通过参数敏感性分析探讨了隧道残余轴力、地基反力系数、地震波入射角及波长对盾构隧道纵向地震响应的影响规律。结果表明:残余轴力越大,等效梁整体刚度提升越大,盾构隧道地震响应越小;且入射角小于45°时,残余轴力对隧道地震响应的影响更加显著。地基反力系数越大,隧道整体挠度和环间局部非连续变形均越大;波长在20~100 m范围内的地震波更容易导致隧道环缝间发生较大的张开和错台。以上研究成果可为盾构隧道纵向抗震设计提供理论支撑。
How to estimate the seismic response of shield tunnels reasonably has been a significant issue in both industry and academia.Compared with the transverse seismic response,the longitudinal seismic response is more complex.The shield tunnel is modeled as a Timoshenko beam on Winkler foundations,considering both residual axial force and additional axial force due to longitudinal seismic.A theoretical model was presented to consider the longitudinal and transverse stratum displacements.The longitudinal seismic response of shield tunnels was solved using the finite difference method.The theoretical model and calculation method were validated through case studies of stagger-assembled shield tunnels with a 6.2 m diameter.Considering axial force increased the overall stiffness of shield tunnel,resulting in decreased internal force and deformation response.The proposed method was degraded to the traditional one when the axial force is neglected.The influences of residual axial force,seismic wavelength,seismic incidence angle and foundation reaction coefficient on the longitudinal seismic response were further explored.With the increase of residual axial force,the overall stiffness of shield tunnel increased,and the peak seismic response of shield tunnel decreased.When the incident angle is less than 45°,the influences of residual axial force and foundation reaction coefficient on the peak response were more significant.With the increase of the foundation reaction coefficient,the tunnel deflection and the discontinuous deformation between joints increased.Wavelengths between 20 m and 100 m may lead to greater opening and dislocation between joints.These studies can provide theoretical support for the longitudinal seismic design of shield tunnels.
作者
任璐瑶
吴镇杰
黄啟超
关振长
REN Lu-yao;WU Zhen-jie;HUANG Qi-chao;GUAN Zhen-chang(College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350116,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第10期2971-2980,共10页
Rock and Soil Mechanics
基金
国家自然科学基金(No.52278399)。
