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【目的】冻结法施工中,为了工后跟踪注浆及控制融沉,必须了解地铁联络通道解冻温度发展规律。【方法】以软土隧道联络通道冻结法工程为背景,对解冻温度场、深层土体温度变化规律等进行了实测;为更有效控制融沉,对其跟踪注浆时机及顺序、注浆工艺及材料进行了优化。【结果】联络通道解冻20 d内,部分土体温度开始达到0℃附近,冻土进入相变阶段;入土深度越大,土体相变阶段持续时间越长;软土融沉主要发生在解冻前2个月,侧墙及顶部完全解冻需要4个月,则跟踪注浆至少应持续的时间为3~4个月。【结论】控制融沉过程中,注浆应按照由底部→顶部→侧墙的顺序先后进行;同时要根据实测温度和地面沉降量实行双控标准。合理安排施工顺序和注浆参数,加强监测,可以进一步使得联络通道周边土层受融沉影响范围缩小,降低联络通道顶部受融沉的影响程度。
【Objective】 In freezing construction, in order to track grouting and control thaw settlement in the post-construction period, it is necessary to understand the law of development of thawing temperature of subway connecting corridor. 【Method】 Based on the freezing tunneling project in soft soil tunnel, the temperature field and the temperature variation of deep soil were measured. In order to control the thawing settlement more effectively, the timing and sequence of grouting, the grouting technology And the material has been optimized. 【Result】 During the 20 days after thawing of the contact channel, the temperature of some soil began to reach around 0 ℃ and the frozen soil entered the phase transformation phase. The larger the depth of soil entry, the longer the phase of soil phase transformation. The thawing of soft soil occurred mainly in thawing In the first 2 months, it takes 4 months for the side wall and the top to completely thaw, and the tracking grouting should last for at least 3 to 4 months. 【Conclusion】 In the process of thaw control, the grouting should be carried out in order from bottom → top → side wall. At the same time, double control standard should be implemented according to the measured temperature and ground settlement. Reasonably arranging the construction sequence and grouting parameters and strengthening the monitoring can further reduce the influence range of the soil around the contact channel due to thawing and reduce the influence of thaw settlement on the top of the communication channel.