基于三维非连续接触模型的管片与接头结构力学特性研究

发布时间：2018-01-30 09:51

  本文关键词： 盾构衬砌 管片接头 三维非连续接触模型 静动力分析 侧向卸载 多尺度混合建模技术　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：盾构隧道衬砌的最重要特征是采用管片拼装而成,而接头结构的存在使得盾构衬砌在受力与变形方面与一般整体式隧道衬砌存在显著差异,尤其在列车荷载的反复作用下,管片接头结构常常发展为隧道的病害多发点。 本论文以国家重点基础研究发展计划项目(2011CB013802)等课题为依托,采用数值计算方法系统研究正常服役及邻近基坑开挖卸载条件下的地铁盾构管片与接头结构静动力特性。主要内容和结论如下： (1)充分考虑盾构隧道结构特征,运用非线性接触理论,模拟管片接头结构和管片衬砌与围岩及道床之间的相互作用,建立道床-管片-围岩的三维非连续接触模型,并通过引入无限元静动力人工边界及列车动力荷载,使模型可以在静力计算的应力应变基础上进行列车荷载作用下的隧道动力响应分析。 (2)基于道床-管片-围岩的三维非连续接触模型,对盾构管片与接头结构在围岩静压及列车动载作用下的受力与变形进行了分析,得到了管片接头结构的变形、应力、接头螺栓内力在列车动载作用下的变化规律。 (3)结合多尺度混合建模技术,研究邻近基坑开挖过程中盾构管片与接头结构的受力变形规律及控制指标。随着邻近基坑开挖,管片与接头结构的应力和变形均大幅增加,且当衬砌竖向收敛率大于3.68‰,轴线水平偏移率大于0.53‰时,应对盾构隧道性态进行特别关注,部分接头变形、接头处混凝土应力、接头螺栓内力已经达到使用极限。 (4)研究了邻近基坑开挖卸载对管片与接头结构动力特性的影响。侧向卸载前后结构的动力响应时程曲线变化规律一致,但侧向卸载使隧道的动力响应有所增大,且靠近基坑一侧的接头结构动力响应增大最多。
[Abstract]:The most important feature of shield tunnel lining is that the pipe piece is assembled , and the existence of the joint structure makes the shield lining significantly different from the general one - piece tunnel lining in the aspects of stress and deformation , especially under the repeated action of train load . Based on the research and development plan project of the national key basic research and development plan project ( 2011CB13802 ) , this paper uses numerical calculation method to study the static dynamic characteristics of metro shield segments and joint structures under normal service and adjacent excavation unloading conditions . The main contents and conclusions are as follows : ( 1 ) taking fully into account the structural features of shield tunnel , using nonlinear contact theory , simulating interaction between pipe joint structure and pipe piece lining and surrounding rock and ballast bed , establishing three - dimensional non - continuous contact model of ballast bed - tube sheet - surrounding rock , and introducing infinite element static power artificial boundary and train dynamic load , so that the model can carry out tunnel dynamic response analysis under the action of train load on the basis of stress strain calculated by static force . ( 2 ) Based on the three - dimensional discontinuous contact model of bed - tube - surrounding rock , the stress and deformation of shield segment and joint structure under the action of static pressure of surrounding rock and dynamic load of train are analyzed , and the rule of deformation , stress and internal force of joint bolt under the action of train dynamic load is obtained . ( 3 ) Combined with multi - scale hybrid modeling technology , the stress deformation law and control index of shield tube sheet and joint structure in excavation of adjacent foundation pit are studied . As the vertical convergence rate of adjacent foundation pit is greater than 3.68 鈥，

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