地面堆载下盾构隧道管片与环缝接头的性状分析

Shield tunnel segment and circumferential joint performance under surface surcharge

针对地面堆载对隧道管片与环缝接头影响的问题,提出地面堆载对下方隧道管片及环缝接头影响的三维数值分析模型和方法.该方法采用连续体有限元模型分析堆载引起的附加应力,并提取应力调整系数,将盾构隧道每环拼装结构等效为均质圆环、环与环之间采用螺栓连接,进行应力叠加三维荷载-结构分析.减少计算工作量,反映盾构隧道主要纵向特性.应用该方法对杭州地铁1号线隧道管片以及环缝接头在堆载作用下的响应进行分析,与现场监测结果进行对比.结果表明,数值模拟结果与现场结果有着较好的吻合,能够有效揭示隧道管片和环缝接头在堆载作用下的变形和破坏规律.

A three-dimensional numerical method which can analyze the influence of surface surcharge on the segment and circumferential joint of shield tunnel was established aiming at the problem of the surface surcharge effect on the tunnel lining and joint.The continuum finite element model was used to analyze the additional stress caused by the ground loading in the method and a three load-structure numerical analysis was conducted base on the model.Every ring of shield tunnel was equivalent to homogeneous ring and bolt connection was adopted between the ring and ring.The computational effort,was reduced and the main longitudinal characteristics of the shield tunnel was reflected.The method was used to analyze the response of segments and circumferential joints of Hangzhou metro line 1 shield tunnel under surface surcharge compared with the results of field monitoring.Results show that the numerical simulation results accorded well with the field results.The deformation and failure regulation of tunnel segments and circumferential joints under surface loading can be revealed by using the method.