The waterproof mechanism of elastic sealing gaskets
under water pressure is not clear. Hence, based on the analysis of the process
of water pressure action from segment assembly to tunnel leakage, the fluidsolid
coupling calculation model is built by finite element analysis software to
simulate the dynamic process of water seeping into joint elastic gasket. And
then by conducting the waterproof performance test of joint sealing gasket, the
process and mechanism of waterproof performance of gasket are explained, and
the causes for the increased reliability of double elastic sealing gasket are
discussed. The results show that: (1) The fluidsolid
coupling model can directly and finely simulate the process of water breaking
through elastic gasket. (2) During the process from segment assembly to tunnel
leakage, the elastic gasket experiences four stages, i.e. segment extrusion,
external water pushing, water wedge and water breakthrough. (3) When the water
pressure pw<p=α(p0+p1), water acts on the outside of the gasket
face, and the waterproof capacity of gasket still has large redundancy; when α(p0+p1)<pw<α(p0+p1+p2), the sealing gasket is not broken through by the water which wedges
in and still has waterproof capability; and when the water pressure pw>α(p0+p1+p2max), the sealing gasket is broken
through by the water and the leakage happens. (4) The first sealing gasket can
selfrecover because of the contact stress increment
caused by the water in the hollow between sealing gaskets, which increases the
waterproof reliability.
ZHANG Yazhou
,
FENG Shengming
,
YOU Guangming
,
WEN Zhuyin
. Study on Waterproof Mechanism of Shield Tunnel Joints Considering
Water Pressure Process[J]. Tunnel Construction, 2020
, 40(11)
: 1594
-1601
.
DOI: 10.3973/j.issn.2096-4498.2020.11.007
