黄土地区地铁隧道盾构施工时既有房屋的变形规律分析

Analysis of Existing House Deformation and Shield Tunneling Technology in Loess Area

运用FLAC3D软件预测黄土地区隧道盾构施工诱发既有房屋的变形。预测结果表明:盾构施工会造成邻近的砖混楼房条形基础发生不均匀沉降,且沉降量大于规定的允许值(15mm)。在采取合理的盾构推力、盾构连续匀速地推进、增大土体流塑性及二次注浆等技术控制措施后,经实测证明:盾构隧道邻近房屋的变形明显变小,且在规定允许值之内,控制措施效果良好。分析结果表明,黄土地区隧道盾构施工会对距离盾构8～10m范围内的砖混结构造成过大变形。这种变形主要表现为房屋基础沉降不均匀,故在隧道盾构施工中应采取相应的控制措施。

With FLAC3D software,deformation of the existing houses induced by shield construction in loess area is predicted,which proves that the foundation of brick buildings nearby the shield tunneling can generate uneven settlement,sometimes greater than the allowable value of 15 mm.After taking some rational measures,such as the continuous excavation,the increase of soil plasticity flow and secondary grouting,the deformation of the existing houses is controlled within the permission value,the control measures also prove to be effective.The result of the deformation law analysis shows that the shield construction in loess area close to brick buildings within 8～10 m can induce larger deformation,and the building foundation will occur uneven settlement at the same time,therefore,some relevant measures should be taken.