Superlarge diameter shield launching with
shallow overburden faces many problems such as water loss and soil erosion at
portal sealing and difficult control of tunneling and segment attitudes. As a
result, a case study is conducted on shield launching of Chunfeng tunnel. According
to the geological and engineering conditions, the strengthened water sealing
method of Ushaped plain diaphragm + triple pipe jet
grouting is adopted, the sectioned breaking is adopted for portal to reduce the
risk, and as well the tunneling slope is adjusted and the negative ring is
fixed to guarantee the effect. Moreover, for slurry leakage phenomenon, the
methods of adopting back pressure cover, increasing earth pressure on upper
part, and reducing slurry chamber pressure are used to reduce uplift of ground,
thus ensuring normal cycling of slurry for shield launching. Finally, a suite
of superlarge diameter shield launching technology
with shallow overburden is formed.
YOU Yongfeng, LIANG Kuisheng, DU Chuangdong, CHEN Zhengming
. Launching Technology with Shallow Overburden for SuperLarge Diameter Shield in Chunfeng Tunnel[J]. Tunnel Construction, 2021
, 41(S1)
: 382
.
DOI: 10.3973/j.issn.2096-4498.2021.S1.049
