为确保国内首例富水砂卵石地层盾构隧道穿越铁路咽喉区道岔群工程顺利实施，通过工程类比、数值计算与现场监测数据分析相结合的手段，基于列车通过速度与道床形式，提出道岔区道床与轨道变形控制标准（≤1 mm/d），在道岔区纵横抬梁无条件实施的情况下，提出超长大管棚超前预支护、既有人行通道加固与跟踪注浆以及盾构保压与天窗期分段掘进等一系列主动控制措施。实践结果表明： 1）顶进工艺、钻头刚度与导向控制是密实砂卵石地层高精度超长大管棚施工工艺的关键技术； 2）对既有铁路下方人行通道加固，可起到纵向大刚度挑梁的作用，在通道两侧设置的袖阀管跟踪注浆，可有效补偿盾构掘进引起的地层损失与施工扰动位移； 3）在土舱压力与掘削面稳定得到保障时，天窗期盾构分段掘进的不利影响可以得到控制。

In order to guarantee the smooth implementation of first domestic shield tunnel crossing underneath turnout groups of railway turnout area in waterrich sandy cobble stratum, the methods of engineering analogy, numerical calculation and field monitoring are adopted to propose a deformation control standard of less than 1 mm/d for track bed and track based on train running speed and track bed form; and a series of active control countermeasures, i.e. large and superlong pipe roof support, existing pedestrian passageway reinforcement and tracing grouting, and shield pressure maintaining and sectioned boring during railway skylight period, are put forward under the condition that vertical and horizontal lifting beams cannot be constructed. The practice results show that: (1) The jacking technology, bit stiffness and orientation control technology are the keys to high precision and superlong pipe roof construction in dense sandy cobble stratum. (2) The reinforcement for the existing pedestrian passage beneath railway can play a role as longitudinal lifting beam with large stiffness; and the Soletanche tracing grouting conducted in both side of pedestrian passage can effectively compensate for ground loss and disturbance displacement induced by shield tunneling. (3) The adverse influence of shield sectioned boring in skylight period can be controlled when cabin pressure and stability of tunnel face can be guaranteed.