用局部冻结法修复损坏的地铁隧道

Partial Freezing Method Applied in the Restoration of Damaged Subway Tunnels

京沪高铁桩基施工中造成上海某地铁隧道管片破损,大量淤泥流入隧道内部,工程采用台阶式封堵墙对隧道内部土体进行封堵,并对破损隧道内部进行注浆充填。隧道上部土体采用地面充填加固注浆的方法加固扰动土层;修复段采用"地面垂直冻结加固土体,结合隧道内水平冻结加固土体,隧道内开挖构筑"的施工方案;在破损隧道上部及四周3 m范围内进行局部冻结,形成强度高,封闭性好的冻土帷幕。冻土帷幕形成后采用暗挖矿山法进行修复段隧道的开挖构筑施工,对破损管片采用原位修复方案,施工取得圆满成功。通过介绍隧道修复设计方案,并对现场监测数据进行分析,为类似工程提供借鉴。

The construction of the pile foundation of Beijing-Shanghai high-speed railway damaged the tunnel lining of a segment of Shanghai subway with large amounts of sludge silted into the tunnel.This paper introduces the repairing of the damaged tunnel and analyzes the site monitoring data to provide reference for alike projects.Firstly,stepped plugging wall was used to plug the solum in the tunnel,and the internal of the damaged tunnel was grouted.The upper solum in the tunnel was treated by ground filling and grouting to reinforce the turbulent solum.Moreover,the restoration segment was reinforced by vertical freezing on the ground and horizontal freezing as well as excavation construction inside the tunnel.Freezing soil curtain with high strength and good sealing property was produced by partial freezing in the upper damaged tunnel and in its surrounding 3 meters area.Subsequently,mining method was employed in the excavation and the damaged lining was repaired by in-situ restoration.The restoration finally achieved great success.