富水地区土压平衡盾构机停机保压施工技术研究

RESEARCH ON CONSTRUCTION TECHNOLOGY OF PRESSURE MAINTENANCE IN CASE OF SHUTDOWN OF EARTH PRESSURE BALANCE SHIELD MACHINE IN WATER-RICH AREAS

施工过程中盾构机经常需要下穿河流和运营中的桥梁、隧道和铁路等风险源,但由于盾构机设备故障或其他不可控因素,不可避免地将造成盾构机长时间停机情况。如果处理不当,将会造成盾构机机头下沉、盾尾漏水和盾体被周围土体裹死的现象,严重的情况下造成开挖面坍塌、地面塌陷沉降和河水灌入隧道等严重事故。因此,如何在特殊工况下进行盾构机停机保压成为盾构施工领域急需解决的问题。通过采用停机前掘进施工、空隙封堵和土仓注浆等一系列措施,保证了盾构机停机期间土仓压力的稳定性。

Shield machine needs to pass underneath rivers and in-service bridges,tunnels,railways and such risk sources frequently during construction.However,long-term shutdown of shield machine will be unavoidable due to machine fault or other uncontrollable factors.Improper handling will give rise to head sinking of shield machine,tail water leakage and full wrapping of body in surrounding soils,and in severe cases,lead to excavation face collapse,surface collapse&subsidence,pouring of river water into tunnel and similar serious accidents.Therefore,how to realize pressure maintenance in case of shutdown of shield machine under special operating conditions is an issue to be solved immediately in the shield construction field.Stability of earth chamber pressure during shutdown of shield machine can be ensured by taking a series of measures like tunneling construction before shutdown,gap sealing and earth chamber grouting etc.