基于有效接触应力的大张开量盾构隧道密封垫防水性能分析

针对高水压作用下大张开量盾构隧道接缝防水密封垫的设计与选型,提出有效接触应力概念。 依托南京和燕路过江隧道工 程,利用大型有限元软件ABAQUS建立完整的沟槽、橡胶止水条带与弹性密封垫的数值模型,对典型错台及张开工况下管片接缝防 水性能进行分析,揭示大张开量条件下管片接缝密封垫错台及张开时的变形与接触应力分布特性。 研究结果表明: 1)密封垫与密 封垫接触面上的扭曲交互能提高接触面上的有效应力占比; 2)圆形孔密封垫错台情况下,密封垫与沟槽之间的有效应力占比要低 于密封垫与密封垫之间的有效应力占比,密封垫与沟槽间的渗水路径在密封垫防水设计时需重点考虑。

Waterproof Performance Analysis of Water Sealing Gasket of Large Open Shield Tunnel Based on Effective Contact Stress

In order to design and select water sealing gasket for the joint of large open shield tunnel under high water pressure, the concept of effective contact stress is put forward. A complete numerical model of groove, rubber water stop tie and elastic sealing gasket of Nanjing Heyan Road Tunnel Project is built by software ABAQUS. The waterproof performance of the joints of segments under typical segment dislocation and opening conditions is analyzed, and the deformation and contact stress distribution characteristics of the sealing gasket of segment joints under the conditions of segment dislocation and large opening are revealed. The simulation results show that: (1) The distortion interaction between the gasket and gasket contact surface can improve the effective stress ratio on the contact surface. (2) The effective stress ratio between gasket and groove is lower than that between gasket and gasket in case of circular hole gasket, which is a key consideration in the waterproof design of gasket.