地铁隧道建设过程中的如何保证地层稳定性是现在所研究的难题之一，地铁建设引起的地层沉降、周围土体失稳、对周围地下管线造成破坏、对地铁开挖周边高耸建筑的不利影响等，是地铁设计、施工所考虑的重要因素。隧道开挖破坏了围岩的原始应力状态，直接可能导致围岩的破坏失稳，因此，为了维持围岩的稳定状态，必须采取一定的预加固措施，不同的预加固技术适应不同的工况，所以对特定条件下的地铁预加固技术开展研究具有很重要意义。 本文在充分查阅文献的基础上，结合西安地铁一号线洒金桥～北大街区间暗挖段隧道的工程背景，利用大型有限元软件Midas GTS建立数值计算模型，分别对无加固方案，锚杆注浆预加固，水平旋喷注浆预加固，管棚注浆预加固这四种工况进行了模拟分析对比，根据这四种模拟方案的竖向位移和水平位移的比较得出，管棚注浆预加固是大断面浅埋黄土地铁隧道的合理预支护方式。 本文采用现场监测数据和有限元数值模拟相结合的研究方法，将现场监测数据和数值模拟所得出结果进行对比，验证了数值模拟的适用性，也进一步验证了西安地铁一号线洒金桥～北大街区间隧道管棚超前支护这种施工设计方案的合理性，对类似工程有很重要的指导作用。

Formation in the process of subway construction stability study is a big problem that we are facing now , mainly displays in the strata subsidence caused by metro construction, instability of surrounding soils, damage to the surrounding underground pipeline, adverse impacts on the underground excavation surrounding high-rise buildings, which are important factors in the subway design and construction. Tunnel excavation after destroyed the original stress state of surrounding rock, directly may lead to the destruction of the surrounding rock instability. certain pre-reinforcement measures must be taken in order to maintain a stable state of surrounding rock. But different pre-reinforcement technology to adapt to the working condition is different, so the study of the pre-reinforcement technology for metro has important significance. In this paper, on the basis of full access to a large number of literature, combined with xi 'an subway line one sprinkle jinqiao ~ north street concealed excavation section tunnel of the engineering background, using the Midas GTS to set up model.With no reinforcement scheme, bolt grouting pre-reinforcement, horizontal rotary jet grouting pre-reinforcement, pipe roof grouting pre-reinforcement analyzed the four conditions are simulated. According to the simulation scheme of four vertical displacement and horizontal displacement is concluded, pipe roof grouting pre-reinforcement is reasonable support form in big cross section shallow buried loess tunnel. Based on the field monitoring data and the research method of combining the finite element numerical simulation based on the field monitoring data and comparing with the results obtained from the numerical simulation, the applicability of the numerical simulation is verified, also further validates the sprinkle jinqiao ~ north street of xi 'an subway tunnel advanced pipe roof supporting the construction the rationality of design scheme which is an important guiding role for similar projects.