The shield will encounter many problems when tunneling
in extremelysoft fluid plastic stratum, such as difficult posture control,
segment fragmentation, water leakage, and over horizontal convergence. As a
result, a case study is conducted on a tunnel between Qingling road station and
Jianguo road station of Hangzhou metro line 2. The construction difficulties of
shield when tunneling in extremelysoft fluid plastic
stratum are analyzed, suggestions are provided regarding host selection,
opening rate of cutterhead, and relationship between host gravity and the
centroid. Techniques such as thrust balance before driving, synchronous
grouting, earth pressure and excavation management, secondary grouting, segment
assembly and bolt retightening, and pulling plate tensioning, are also
introduced. The applicable results of the recommended methods show that the
shield has a good adaptability in extremelysoft fluid
plastic stratum, and water leakage, vertical posture deviation, and horizontal
convergence are reduced.
LIU Jidong, BAO Zhenhang
.
Construction Technology of Shield Tunnel in Extremely-Soft
Fluid Plastic Stratum
[J]. Tunnel Construction, 2021
, 41(S2)
: 527
-532
.
DOI: 10.3973/j.issn.2096-4498.2021.S2.067
