Many technical issues are encountered during the
construction of the Yima No. 1 tunnel on the Xi′anYinchuan highspeed railway in the waterrich loess stratum, including water seepage on the tunneling face,
soft surrounding rock spalling, primary support deformation and collapse, and
soft foundation of the tunnel bottom. As a result, an indepth study on surface dewatering excavation and soft foundation
reinforcement is conducted, and the dewatering and reinforcement effect is
analyzed. The findings are as follows: (1) Because the designed water gushing
volume is largely different from the actual one based on experience, a deepwell drainage test should be performed first to provide a reference
for water gushing volume parameter design. (2) The practice demonstrates that
advanced surface dewatering for the tunnel crossing deep waterrich soft plastic loess soil layer is feasible. Surface dewatering
which is superior to intunnel drainage, can improve
the stability of the surrounding rock and facilitate tunnel construction. (3)
When tunnel foundations are reinforced with steel tube piles in waterrich softplastic loess stratum, many
disadvantages occur, including large disturbance to tunnel excavation, complex
pile formation, and low water stop and reinforcement effect, whereas Soletanche
grouting performs better.
CHEN Tianming
. Surface Dewatering Excavation and Soft Foundation
Reinforcement Technology for WaterRich Loess Tunnel in
Dongzhi Tableland: a Case Study of Yima No. 1 Tunnel on YinchuanXi′an HighSpeed Railway[J]. Tunnel Construction, 2021
, 41(6)
: 1015
-1023
.
DOI: 10.3973/j.issn.2096-4498.2021.06.014
