The bridge settlement induced by undercrossing of fourline
overlapping smallspacing tunnels should be controlled.
As a result, the numerical simulation is adopted to study the deformation settlement
of Chaoyangxi Bridge and internal force variation of overlapping tunnels on
Nanning Rail Transit Lines 1 and 2. And then the effectiveness of the numerical
simulation and reinforcement measures is verified by monitoring data. Finally,
the measures of steel cofferdam diversion, rotary jet pile reinforcement for
riverbed, Soletanche reinforcement for pile foundation, temporary support
system and shield tunneling parameters control are put forward to ensure the
safe construction of fourline parallel shield tunnels
with small spacing crossing underneath Chaoyangxi Bridge. The results show
that: (1) The fourline tunneling will have a great
impact on the stability of the bridge if no measures are taken, causing the
bridge foundation to tilt seriously and the collapse of some tunnel segments.
(2) Chaoyangxi Bridge was built long ago with complex stress structure system
and is sensitive to strata disturbance, which indicates that the wrapped
grouting reinforcement for bridge foundation and hardening method of the
riverbed with rotary jet pile and concrete plate should be carried out to
prevent the soil above tunnel from sweeping by river.
LI Haiyang
. Analysis of Settlement Control of Bridge Induced by
Undercrossing of Fourline Overlapping Smallspacing Shield Tunnels[J]. Tunnel Construction, 2020
, 40(S1)
: 343
-349
.
DOI: 10.3973/j.issn.2096-4498.2020.S1.044
