沉管隧道接头OMEGA止水带损坏分析及修复技术

Damage Analysis and Repair Technology of OMEGA Gasket in Immersed Tube Tunnel

研究目的:管段接头是沉管隧道的薄弱环节,相比管段本身,极易损坏和老化,特别是建在软土地基上的沉管隧道,常因差异沉降导致接头受损,严重影响沉管隧道的使用寿命。为满足百年运营的要求,就需在运营过程中进行管段接头修复。因此,需要提出一套可靠性高、实施方便并且具有推广性的修复方案。同时,从预防的角度需要针对接头受损原因提出预防措施。研究结论:(1)综合监测数据与现场观测结果分析还原出上海外环沉管隧道OMEGA止水带的三阶段损坏过程;(2)依托该工程提出一套接头修复方案,方案包含沉降控制、接头限位和OMEGA止水带修复三部分,配合分步更换OMEGA止水带的施工筹划,最大程度降低接头修复工程对交通的干扰;(3)针对接头各阶段损坏的原因,提出三类预防建议:增添限位块和注浆孔的设计建议,合理计划岸边地面用途的规划建议以及观测沉降及时注浆的运营维护建议;(4)本文中的修复方案及预防措施可为未来铁路及公路沉管隧道工程提供参考。

Research purposes： As the weak link of immersed tube tunnel, the joint is easily becoming damaged or aged. Especially for those who is built in soft soil foundation, the differential settlement often causes joint damage which can seriously affect the working life of immersed tube tunnel. To meet the operational requirements of a century, the joint needs to be repaired during working life. Thus, it is necessary to bring out a repair plan which is reliable, convenient and with good applicability. Meanwhile, in the view of precaution, the prevention programs corresponding to damage reasons are also requisite. Research conclusions：（ 1 ） Based on the monitored data and field observations, the damage on the OMEGA gaskets of Shanghai outer line tunnel is summarized to a three - stage process. （2） The corresponding solutions are put forward which include settlement control, relative displacement limits and OMEGA gasket repair. The replacement scheme for the OMEGA gasket can minimize the interference on traffic. （3） Corresponding to the causes of damage in each stage, prevention suggestions are given, including adding a GINA stop, planning of the utilization of shoreside ground and grouting according to settlement data. （4） Repair plans and prevention suggestions mentioned in this paper can be promoted as a reference for repair projects of further rail and road immersed tube tunnels.