采用FLAC3D软件建立了交叉隧道的三维有限差分模型，以人工数定激励力模拟列车荷载，计算列车动荷载作用下土体的变形和应力。采用修正动偏应力长期沉降计算模型，结合分层总和法计算软土的沉降，预测交叉隧道的长期沉降规律。分析3种不同行车工况下地基长期沉降，工况1为一辆列车单独通过1#隧道，工况2为一辆列车单独通过2#隧道，工况3为两辆列车同时通过1#和2#隧道。对比不同的列车行驶速度、隧道衬砌刚度及厚度对隧道地基的长期影响。结果表明，由列车荷载引起的地基沉降主要集中在距隧道中心轴20 m范围内；在工况3下土体沉降大于工况1、2沉降之和；车速越快，沉降越小；衬砌刚度和厚度越小，沉降越大，且衬砌厚度对沉降的影响较大，衬砌刚度影响较小。

Three-dimensional finite difference model of cross tunnels is established by FLAC3D to compute deformation and stress of soft soil under metro train cyclic loading which is modeled by artificial numerical exciting force. Modified dynamic deviatoric stress model for long-term settlement of soft soil combined with layer-wise summation method are adopted to calculate tunnel settlement and predict long-term settlement of cross tunnels. Long term settlement in three train-running cases is studied. Case 1, one train traveled through tunnel #1, case 2, one train traveled through tunnel #2, case 3, two trains traveled through tunnel #1 and tunnel #2 separately at the same time. Influences of train speed, stiffness and thickness of tunnel lining on long-term settlement of cross tunnels are studied. The results show that the settlement induced by train loading mainly distributes within 20 m from the central axis of tunnels. Sum of settlement in case 1 and case 2 is less than settlement in case 3; and tunnel settlement decreases with the increasing of train speed, stiffness and thickness of tunnel lining; while the influence of thickness of tunnel lining is more than stiffness of the lining.