双侧壁导坑法在小净距大断面地铁车站施工中的应用

以某浅埋暗挖城市地铁车站为工程背景,研究了双侧壁导坑法在小净距大断面地铁车站施工中的可行性。通过有限元数值模拟计算得到了该施工方法下地铁车站的位移和塑性区时空演化规律,并将计算结果与相关规范值进行比对。分析结果表明,Ⅳ级围岩条件下小净距大断面隧道使用该工法施工时所引起的隧道拱顶沉降、水平收敛及塑性区发展均在允许范围之内,能保证整个施工过程的安全。

Application of Double Side Drifts Method in Construction of Metro Station with Closely-spaced Large Sections

Based on an urban metro station construction with undermining method with shallow overburden, this paper studies the feasibility of double side drifts method applied in the metro station construction with closely-spaced large sections. Through finite element numerical simulation, the time and spatial variation rule of the displacement and plastic zone is obtained, and the calculation results and relevant specifications are compared. The results show that under condition of Ⅳ class surrounding rock,the arch crown settlement, the horizontal convergence and the development of plastic zone, caused by this construction method, of the tunnelwith closely-spaced large sections are within the allowed scope, and the whole construction safety can be ensured.