Abstract:

In this paper, 4 crosssection types of hydroexpansive rubber sealing gaskets, i.e. yin and yang concaveconvex, circular hole, combshape and rectangular shape, are designed based on the first connection gallery bored by shield on Line No. 3 of Ningbo Rail Transit. The feasibilities of the 4 crosssection types of sealing gaskets are analyzed, and the types of yin and yang concaveconvex and rectangular shape of sealing gasket are selected as primary schemes. The contact stresses of abovementioned two types of crosssection are studied by Abaqus/Explicit computation module, and the waterproofing pressure test is designed to verify the waterproofing ability of the sealing gasket with rectangular crosssection with higher contact stress in numerical simulation. The results show that: (1) The numerical simulation results show that the maximum contact stress and average contact stress of contact face decrease with the increase of joint opening; during the compression and expansion phases, the contact stresses of sealing gasket with rectangular crosssection are larger than that of sealing gasket with yin and yang concaveconvex crosssection, hence, the rectangular shape crosssection is selected as an alternative scheme. (2) The waterproofing pressure test show that the waterproofing pressure of sealing gasket with rectangular crosssection increases obviously after preserving pressure for 48 h, and the larger the joint opening is, the lager the increase of waterproofing pressure is. (3) According to the numerical simulation results and test results, the sealing gasket with rectangular crosssection can meet waterproofing requirement of 0.6 MPa.

Key words: connection gallery bored by shield, sealing gasket design, numerical simulation, water tightness test, contact stress, hydroexpansive rubber sealing gasket