针对城市长距离大断面地下空间冻结工程的冻胀特性问题，依托上海地铁18号线国权路站双线隧道下穿既有车站冻结工程，基于热力耦合方程，利用有限元软件建立三维数值模型，结合室内试验所得物理参数，研究该工程的冻胀位移场演化规律，并探究错峰冻结、调整盐水温度等措施对冻胀位移场的影响规律。在本试验条件下，研究结果表明：① 冻胀引起的车站底板变形主要发生于积极冻结期；双线隧道同时冻结模式下，冻结45 d时车站底板竖向位移量达到冻结90 d时竖向位移量的77.72%。② 冻结90 d时，错峰冻结工况下车站底板竖向位移量较双线隧道同时冻结时减小了7.7%，表明错峰冻结避免了同一时间段内的冻胀叠加效应，一定程度上降低冻胀效应。③ 冻结90 d时，调整盐水温度工况下车站底板竖向位移量较温度调控前减小34.2%；表明调整盐水温度可控制冻土扩展速率，有效降低冻胀效应。实际工程中，采用错峰冻结、调整盐水温度等措施协同控制冻胀，车站底板最大竖向位移为25.41 mm；数值模拟所得车站底板抬升规律与实测数据基本一致，有效指导了工程施工。

Aiming at the frost heave characteristics of long-distance and large-section underground freezing projects in cities, the double-line tunnel of Shanghai Metro Line 18 undercrossing an operation station was select as an example,a three-dimensional numerical model was established by using finite element software based on the thermal-mechanical coupling equation. Combined with the physical parameters obtained from laboratory tests, the evolution law of frost heave displacement field of the project was studied, and the influence of measures such as the staggered peak freezing and the adjustment of brine temperature on the frost heave displacement field was explored. Under the experimental conditions, the results show that: ① the deformation of the station floor caused by frost heave which mainly occurs in the active freezing period. When the double-line tunnel is frozen at the same time, the vertical displacement of the station floor at 45days of freezing reaches 77.72% of the displacement at 90 days of freezing. ② When the freezing time reaches 90 days, compared with simultaneous freezing, the displacement of the station floor reduced by 7.7% under the condtion of staggered peak freezing. The superposition effect of frost heave in the same time period is effectively avoided, and the frost heave effect is reduced to a certain extent. ③ When the freezing time reaches 90 days, compared with simultaneous freezing, the displacement of the station floor reduced by 34.2% under the condtion of adjusting the brine temperature, it shown that the expansion rate and frost heave effect of frozen soil are effectively controlled. In engineering practice, measures such as staggered freezing and adjusting brine temperature are used together to control frost heave, and the maximum vertical deformation of the station floor is 25.41 mm. The deformation law of the station floor obtained by numerical simulation is basically consistent with the measured data, which effectively guided the construction of the project.