黄土地铁隧道盾构施工引起地层沉降，影响周围既有建筑安全，并制约盾构快速施工。在理论分析饱和黄土地铁隧道围岩力学特性、变形机理以及地层沉降变形机理基础上，总结地铁隧道施工方案的可行性影响因素；结合工程实例，利用ANSYS建立三维模型，FLAC3D对饱和黄土隧道盾构施工进行数值模拟，研究隧道掘进在不同覆土层厚度、施工速度及壁后注浆加固条件下的地层沉降及隆起规律，并提出该工程隧道施工沉降预测及沉降控制措施。研究表明： (1)开挖距隧道模型边界24m以后，地层的沉降及隆起位移开始增长缓慢；开挖至42m时，拱顶的沉降值、拱底的隆起值达到最大，分别为2.3719cm与2.5094cm。通过对研究结果和工程监测数据进行对比分析，得出采用盾构法穿越饱和软黄土地层是可行的，符合规范及工程实际要求。 (2)覆土层厚度从8m增大到16m时，地表最大沉降由1.5057cm减小至1.1297cm，拱顶最大沉降由2.6497cm减小至2.2537cm，覆土层厚度在13m以后地表及拱顶沉降变化平缓，因此合理的覆土层厚度为取10m~13m。 (3)施工速度从0.5m/d增大到4m/d时，地表最大沉降增加约31.91%，拱顶最大沉降增加约23.15%。在满足工期的条件下，施工速度应控制在2m/d以内。 (4)注浆材料弹性模量为0.46MPa、4.6MPa、46MPa时，地表最大沉降分别为1.2855cm、1.2245cm和1.1736cm，拱顶最大沉降量分别为2.4655cm、2.3719cm和2.2886cm。 研究成果为类似工程施工提供了参考。

Strata subsidence has caused by the subway tunnel which using the shield construction crossing loess strata ,has effect on both the around building’s safety and the speed of the shield construction. Being based on the theoretical of the surrounding rock mechanical properties , the deformation mechanism and the deformation of stratum subsidence mechanism of saturated loess subway tunnel, sum up the feasibility factors of the construction of the subway tunnel; Combined with the engineering, using the ANSYS to build the 3D model, FLAC3D to numerical simulation of saturated loess tunnel shield construction, to research the regular of strata subsidence and uplift in different soil thickness, construction speed and the condition of the wall after grouting reinforcement ,and put forward the subway tunnel’s construction settlement prediction and control measures. The research shows that: (1)The growth of the strata subsidence and uplift displacement is slowly when the excavation of tunnel boundary after 24 m; When to 42 m, the vault’s subsidence and uplift are maximum, 2.3719 cm and 2.5094 cm respectively. By comparing the results of the research and the engineering monitoring data,we can conclude that the shield method is adopted for the saturated soft loess strata subway tunnel, and conform to the requirements of the specification and the engineering practice. (2) When the soil thickness increased from 8 m to 16 m, the maximum of the earth’s surface subsidence decreased from 1.5057 cm to 1.1297 cm, the maximum of vault subsidence decreased from 2.6497 cm to 2.2537 cm, the subsidence is changing slowly after the soil thickness is 13 m, so the reasonable thickness is 10 m ~ 13 m. (3) When the construction speed increased from 0.5 m/d to 4 m/d, the maximum of the earth’s surface subsidence increased about 31.91%, the maximum of vault subsidence increased about 23.15%. Under the condition of meeting the project duration, the construction speed should be controlled within 2 m/d. (4) The grouting material elastic modulus is 0.46 MPa, 4.6 MPa, 46 MPa,, the maximum of the earth’s surface subsidence are 1.2855 cm, 1.2245 cm and 1.1736 cm, the maximum of the vault subsidence are 2.4655 cm, 2.3719 cm and 2.2886 cm. The research provides reference for similar engineering construction.