Abstract:

FEM is used on 4 types of GINA gaskets under working conditions of axial compression and axiallateral compression, so as to study the influence caused by structural types of GINA gaskets on watertightness. An analysis is made on the influence of 3 structural variations of GINA gaskets, including gaskets with body openings, gaskets with bottom openings, and gaskets with tip ribs, on the stressing and waterproofing efficiency, by using superelastic elements and contacting elements to simulate the rubber materials and the contacting effects. The study results show that: 1) The contacting pressure at the point between the tip rib and the steel plate is the smallest, which is the weak point of waterproofing; 2) The distribution of the contacting pressures on the bottom of GINA gaskets can be more uniform if openings are installed on bottoms or bodies of gaskets, however diameters of openings should be proper and openings should be distributed uniformly; 3) The primary waterproofing effect of GINA gasket with tip ribs is poor, and overturning may occur when a gasket is high; 4) GINA gaskets with body openings can relieve the stress concentration caused by tip ribs, however, they have poor capacity to bear the lateral water pressures because of their smaller body stiffness.

Key words: immersed tunnel, GINA gasket, structure type, numerical simulation