Research On Ground Freezing Effect Of A Cross Passage Of Jinji Lake Tunnel In Suzhou Subway

Freezing method is mainly suitable for weak water-bearing stratum, its craft is the use of a refrigerator on frozen liquid cooling, and through the circulation line will be frozen liquid delivery to need frozen strata area, make the ground freezing and increase the strength of the formation and stability. Between up and down tunnel of the plan and design in urban subway tunnel, has usually need to set up cross passage. When the fire, water or sudden events such as collapse of a tunnel occur in subway operation period, passengers can contact after cross channel is transferred to the other of a tunnel, and then rapidly evacuate to the ground. In the soft soil(soft clay) geological condition, the technique of artificial freezing method (technology of artificial freezing) is a kind of important method which is the effective implementation of the deep foundation pit (deep foundation pit) excavation and liaison channels excavation. Researching the occurrence and development process of liaison channels frozen curtain (Freezing curtain), and has important engineering significance for actual engineering.This paper combined with jinji lake in suzhou subway shield tunnel to study the freezing method construction of connecting passage, through information research, discusses the principle and technological process of freezing method, carry out the research of jinji lake tunnel connecting passage freezing method construction plan and design of freezing hole layout, refrigeration, freezing station, excavation and building construction, and design of monitoring and control technology parameters, control technology of thaw collapse; Freezing temperature field analysis model is established on the basis of the active freezing and maintain the brine temperature monitoring, and based on the design of physical parameters of the typical soil freezing temperature, freezing curtain thickness in Suzhou; Research the expansion of the frozen curtain change process when Frozen pipe was under the different diameter, and reveals certain observation point temperature and frozen water content changes in the time history curve; The measured temperature curve was used to verify the rationality of the numerical simulation curve of temperature; Optimize the freezing hole layout and the selection of pipe number; Research results for the design and construction of freezing, contact horizontal channel excavation and risk prevention and control has a certain guiding value.