Study on distribution form and variation mechanism of multi circle horizontal cup freezing temperature field in water rich formation
In order to master the distribution form and development law of multi circle horizontal cup freezing temperature field in water rich stratum,taking the freezing reinforcement project of Kunming Metro Urban Rail Transit Line 5 as the background,the variation law and internal mechanism of freezing curtain temperature field are studied through field monitoring,numerical calculation and indoor test,and the variation law of freezing wall temperature field in the formation process is analyzed.The test results show that under the action of external cooling plan,the temperature field of freezing wall can be divided into four stages according to the temperature change process:rapid cooling stage,latent heat release stage,stable temperature stage and freezing maintenance stage.There is a certain correlation between the rate of curve change in each stage and the change in unfrozen water content of the samples within the reinforcement range.Unfrozen water often affects the overall temperature distribution of the frozen wall by influencing thermal parameters such as specific heat capacity,thermal conductivity,and latent heat.The change of unfrozen water content affects the heat conduction form during the freezing process of the sample by changing the geometric position relationship between the frozen ice cylinder and the soil column,and the specific heat capacity increases gradually with the decrease of temperature in the positive temperature stage.
artificial freezingcup-shaped freezingfrozen curtainunfrozen water contentthermal parameters
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