浅埋暗挖大断面区间隧道施工地表沉降规律及控制措施研究

Study on Surface Subsidence Law and Control of Underground Excavation of Shallow Large-span Tunnel Construction

运用数值模拟和现场监测的方法对石家庄地铁1号线留村站~火炬广场站区间浅埋暗挖大断面区间隧道施工引起的地表沉降规律进行了研究,研究结果表明:不同施工阶段地表沉降变形量存在较大的差异,中间导洞开挖对地表沉降的影响较大,约占地表最终沉降量的43%,隧道封闭成环后再拆除支撑能有效减少对地表沉降的影响;对拱顶土体采取深孔注浆、径向注浆等加固措施,可有效增加上部土体强度,减少地层变形。

Based on the method of numerical simulation and field monitoring to study the surface subsidence deformation caused by underground tunnel construction in Shijiazhuang subway line 1,Liucun station-Huoju square station. The results show that,at different stages of construction the surface subsidence is very different,The middle pilot tunnel excavation has great effect on the surface settlement,accounting for about 43% of the final settlement of the surface,the tunnel closure after removing support can effectively reduce the impact of surface subsidence. Deep hole grouting,radial grouting and other reinforcement measures should be taken in the vault to increase the strength of upper soil and reduce formation deformation.