浅埋暗挖区间水平降水导洞施工技术

Construction Technology of Horizontal Precipitation Pilot in Shallow-buried Interval Tunnel

北京地铁甘家口站~玉渊潭东门站区间正线施工至钓鱼台时突然出现大量涌水涌砂现象;针对暗挖掌子面地下水,采取了明排、注浆、地表疏干井等措施,仍未有效解决。根据周边环境、地质条件、降水井设计及施工情况、开挖过程中水量方向等,制定了以洞内降水为主的思路,通过增设施工通道迂回施工,避开含水地层,从新增横通道另开洞门,施工水平降水导洞,导洞内施工降水井等关键技术,最终达到预期降水效果,对类似工程有一定的借鉴作用。

A great deal of water inrush and gushing sand disaster suddenly appeared at the Diaoyutai section,which was belonged to the interval mainline construction between Ganjiakou Station and Yuyuantan East Gate Station. Aiming at the underground water of tunnelling face,some measures were taken such as open draining,grouting and the surface drainage wells,but it still hardly worked. According to the surrounding environment,geological conditions,dewatering well design,the construction situation and water flow direction,we formulated the idea that the precipitation taking place inside the tunnel. By adopting the key technologies of adding channel for circuitous construction,avoiding water-bearing strata,digging portal from the new transverse channel,constructing horizontal precipitation pilot,constructing dewatering well inside the pilot,and finally the effects of expected precipitation were achieved. It could provide some references for similar projects.