为了研究在软弱围岩隧道三台阶开挖过程中，施工工序对围岩变形、应力的空间效应影响，以某软弱围岩双线铁路隧道为例，通过数值模拟，分析隧道周边围岩的变形和应力的空间变化过程，并将计算结果与现场监测数据进行对比验证。结果表明： 先行最大拱顶沉降和先行最大收敛位移分别达到总位移的53.3%和67.28%；上、中台阶的开挖对拱顶和起拱线处围岩应力的变化影响巨大；锁脚旋喷桩与围岩之间的压力变化受上、中台阶开挖的影响较大，且待开挖台阶土对隧道周边产生外撑力，能对接触压力有一定影响。

The deformation of rock mass and the spatial effect of stress of a doubletrack railway tunnel in weak rock mass are analyzed by means of numerical simulation, and the calculation results are compared with the monitoring data, so as to investigate into the influence of construction on the deformation of rock mass and the spatial effect of stress. Conclusions drawn are as follows: 1) The maximum presettlement of the crown takes 53.3% of the total settlement, and the maximum preconvergence takes 67.28% of the total convergence. 2) The excavation of the top heading and the bench has great influence on the variation of the stress at the crown and the spring line. 3) The excavation of the top heading and the bench has great influence on the variation of the stress between the footlocking jet grouting piles and the rock mass, and the bench soil to be excavated has bracing effect on the tunnel contour and has some influence on the contact pressure.