地铁隧道通过浅覆土砂卵石地层段开挖面失稳盾构机脱困技术

以长沙地铁二号线盾构机过某砂卵石地层段时开挖面失稳,出现地表塌陷为实例,针对埋深较浅、砂卵石层较厚的地质特点,采取地表注浆加固与盾构机内部处理相结合的方法,较好地起到了固岩、堵水、减少扰动的作用。同时,运用监控量测的手段,及时优化施工,使隧道通过坍陷地段,盾构机成功地从砂卵石地层中脱困。

Relief Technology for Subway Shield Machine in Instable Excavation Face of Shallow Buried Earth and Sandy Pebble

Based on the engineering example of instability and surface subsidence occurred when Changsha subway tunnel shield machine passing the section of earth and sandy pebble,in light of the geological characteristics of shallow buried depth and thick sandy pebble layer,the methods of surface strengthening with grouting and internal shield machine processing are taken,which plays an effective role in reinforcing rock,stopping water,reducing disturbance.At the same time,the means of monitoring measurement are used to conduct timely construction optimization to ensure the construction through the subsidence area and successfully relieve the shield machine from the sandy pebble formation.