Failure mechanism of joint waterproofing in precast segmental tunnel linings
Failure mechanism of joint waterproofing in precast segmental tunnel linings
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DOI：
10.1016/j.tust.2018.11.003
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发表时间：
2019-02-01
影响因子：
6.9
通讯作者：
Mosalam, Khalid M.
中科院分区：
文献类型：
--
作者：
Gong, Chenjie;Ding, Wenqi;Mosalam, Khalid M.
盾构隧道无论在施工阶段还是运营阶段，渗漏水都是一个主要问题。在工业上防止地下水渗透的实际解决方案是在隧道接缝处安装三元乙丙橡胶(EPDM)垫片。虽然过去的一些研究主要集中在接头防水性能方面，但本文提出了一种基于有限元分析的密封机理。首先建立了一个概念模型，以确定在侧向水压作用下垫片接头的密封性能。建立了非线性有限元模型来模拟槽垫式密封胶的行为，并用实验数据验证了模型的有效性。非线性数值分析的结果(包括垫片的超弹性本构模型、复杂的接触特性和大变形)表明了接缝防水的破坏机理。重点分析了接缝开度、接缝偏移量和接缝旋转对防水性能的影响。计算结果表明，随着接缝开度或接缝转数的增加，接缝防水能力显著降低。由于接触面的变化，在不同的接缝偏置情况下，防水能力会有所不同。对于原型隧道，建议控制6.42rad的接缝开度、0.0505 rad的正接缝旋转或0.0141 rad的负接缝旋转，以保持其防水性能。
Water leakage is a major issue for shield tunnels in both the construction and operational stages. The practical solution in industry with relation to the prevention of groundwater penetration is to implement ethylene-propylene-diene monomer (EPDM) gaskets at tunnel joints. Although a few past research has focused on joint waterproof performance, this paper proposes a sealant mechanism based on the finite element analysis. A conceptual model is first established to identify sealant behavior of gasketed joint subjected to lateral water pressurization. A nonlinear finite element model is developed to simulate the gasket-in-groove sealant behavior, and the performance of the model is validated with experimental data. Results of the nonlinear numerical analyses (incorporating a hyperelastic constitutive model of the gasket, complex contact properties, and large deformation) demonstrate the failure mechanism of joint waterproofing. Emphasis is placed on quantifying the effects of joint opening, joint offset and joint rotation on waterproof capacity. The computed results indicate that joint waterproofing capacity significantly decreases with increasing joint opening or joint rotation. The waterproofing capacity varies under different joint offset scenarios because of change of contact interfaces. For the prototype tunnel, it is suggested to control a 6.42 mm joint opening, a 0.0505 rad positive joint rotation or a 0.0141 rad negative joint rotation to maintain its waterproofness.