Development characteristics of freezing temperature field of coastal soft soil strata

In order to research the temperature fields and development law of freezing in the construction of connected aisle in coastal soft soil stratum, based on connected aisle between Luoxiu road station and Baise road station of Shanghai subway Line 15, the thickness and average temperature of frozen curtain, and the freezing process were analyzed. The temperature fields and development law of freezing were predicted by the three-dimensional numerical model of the connected aisle and the temperature data which were analyzed. The results show that the inherent pressure in soft soil causes initial pressure in the pressure relief hole. A lot of cement paste was injected during the burial of the freezing tubes, which will inhibit water migration and reduce the effect of frost heaving during the freezing process. The process of freezing can be divided into four stages by temperature:rapid drop of temperature, drop of temperature decreases first and then increases, slow drop of temperature, temperature stability. The rate of development speed of frozen inside and outside curtain is 1.42︰1. The grey silt freezes faster than silty clay with silt. The development freezing speed of silty clay with silt and grey silt are 20.02 mm/d and 29.75 mm/d.