黄土地区暗挖段隧道中洞施工地层变形特性分析

以西安地铁隧道为工程背景,在现场实测和数值模拟的基础上,研究了浅埋暗挖地铁隧道穿越黄土区时围岩的位移变形规律.结果表明,采用台阶法施工,上导引起的沉降量远小于下导引起的沉降量,下导开挖后应在最短时间内进行初期衬砌支护;上台阶开挖所引起的拱顶沉降量大于下台阶引起的沉降量,其沉降值在下导掌子面通过2D(D为隧洞洞径)距离后逐渐趋于稳定.

An analysis of the Characteristics of Stratum Deformation in the Tunnel' s Mid-cavern Construction in the Shallow Embedded Region in Loess Area

The paper researches the deformation law of the displacement of the surrounding rock when the shallow embedded underground railway tunnel passes through the loess area on the basis of on-spot measurement and numerical simulation against the background of Xi’ an underground railway tunnel.The research shows that with the bench method,the settlement quantity caused by the upper guide would be much smaller than that by the lower guide,and the initial lining support must be completed within the shortest time after excavation.The research also indicates that the settlement quantity caused by upper bench excavation is larger than that by lower bench excavation and the settlement quantity comes to be stable after the tunnel face of the lower guide passes through a distance of 2D(D is the diameter of the tunnel).