Presently, owing to the demand of construction scale
and design function, many superlargediameter
shields have been widely used in tunnel engineering in railways, highways,
urban rail transits, underground utility tunnels, and other areas. In this
paper, a preliminary statistic on the superlargediameter (more than 15.5 m) shield tunnel projects around the world
is presented. The main risks of largediameter shield tunneling,
such as main bearing damage and failure, segment floating after segment
assembly and removal from shield tail, cutter wear increasing with shield
diameter, mud cake bonding on cutterhead, hysteretic discharge of muck, and
cutterhead heating, are summarized. Additionally, related countermeasures are
provided based on case analysis. Moreover, suggestions are put forward
regarding main bearing seal of earth pressure balance shield and slurry shield,
floating risk after segment assembly and removal of shield tail, cutterhead
selection, mud cake bonding and hysteretic discharge of muck, preexploration of complex geology, and blasting and grouting
consolidation of sea bedrock.
QIAN Qihu
,
CHEN Jian
. Analysis of Tunneling Risks of LargeDiameter Shield and Thoughts on Its Challenges[J]. Tunnel Construction, 2021
, 41(2)
: 157
-164
.
DOI: 10.3973/j.issn.2096-4498.2021.02.001
