To investigate the impact
of factors such as waterstops, interface agents, and interface roughness on the
impermeability of tunnel lining construction joints, and to enhance the water
pressure resistance of linings in water-rich
tunnels, the waterproof structure of tunnel lining construction joints is
examined to identify the crucial influencing factors of their impermeability
performance. The research includes designing and performing indoor
impermeability tests on 162 specimens to conduct a sensitivity analysis of
various factors and elucidate their mechanisms of action. The findings
demonstrate that: (1) Construction joints with pouring intervals exceeding 7
days exhibit a decrease in concrete impermeability by 2 to 3 orders of
magnitude, influenced by the impermeability at the interface between the new
and existing concrete, and between the waterstop and concrete. (2) Reducing the
pouring interval and applying interface agents effectively lower the
permeability coefficient at the interface between new and existing concrete.
(3) Enhancing the roughness of the construction joint interface through
chiseling does not significantly improve impermeability; excessive chiseling,
in fact, diminishes it. (4) With a pouring interval of 7 days and no chiseling,
the average relative permeability coefficient at the interface between the
rubber waterstop and concrete is 47.5% of that at the interface between new and
existing concrete, indicating superior impermeability in construction joints.
(5) The permeability coefficient at the interface between steel plate
waterstops and concrete is approximately equal to that between new and existing
concrete, functioning to extend the seepage path length.
ZHANG Zhi′en
,
LEI Jun
,
LI Liping
,
WANG Lichuan
,
LIU Zhiqiang
,
ZHENG Bo
,
HUANG Mingli
,
GUAN Wei
. Experimental Research on
Impermeability and Influencing Factors of Tunnel
Lining Construction Joints[J]. Tunnel Construction, 2024
, 44(8)
: 1609
-1616
.
DOI: 10.3973/j.issn.2096-4498.2024.08.008
