水下盾构隧道管片钻穿会引起大量涌水突泥,对隧道建设及运营造成重大影响,且采取的隧道修复措施将影响隧道的长期运营安全。以某地铁隧道被意外钻穿的实例为工程背景,为确保水下隧道意外钻穿破坏时,可以做到临时封堵有效,永久修复满足百年使用要求,提出修复思路。在水面利用浮船进行海上袋装水泥封堵,然后筑岛截断隧道与海水的联系;
临时封堵后监测管片变形、复核隧道中线,明确钻孔对隧道限界的影响; 通过计算对结构安全性进行评价,明确钻孔对管片结构受力影响较小。在确保隧道钻穿对隧道限界及结构的影响可控后,采取地面注浆、洞内注浆、倒锥形封堵、洞内设置内撑钢板相结合的方案,对隧道钻穿处进行治理,保证隧道的安全运营。在隧道周边施工时,应加强隧道保护意识,避免对既有隧道造成破坏。
The accidental drilling of underwater shield tunnel
will produce a large amount of gushing water and mud, which will significantly
affect the construction and operation of the tunnel, and the repair measures
will affect the longterm operation safety of the tunnel.
When accidental drilling damage occurs to the underwater tunnel, effective
temporary blocking and sealing should be carried, and the one hundredyear operation of tunnel after repairing should be guaranteed. As a
result, the repairing idea is put forward. Firstly, the floating ship is used
to carry out cement sealing, and the isolation island is built to cut off the
connection between the tunnel and the sea water. And then the deformation
monitoring on segment and recheck of tunnel central line are carried out after
temporary sealing, and the influence of the drilling hole on the tunnel
boundary is clarified. The structural safety is evaluated by calculation, and
the evaluation results show that the drilling hole has little influence on the
segment structure. Finally, the scheme of ground grouting, inhole grouting, inverted cone sealing and inhole
bracing steel plate is adopted to repair the tunnel drilling position and ensure
the safe operation of the tunnel. In addition, the tunnel protection should be
paid attention to when carrying out relevant treatments.