Development Characteristic Analysis of Freezing Temperature Field in Ultra-Long Contact Channel
To master the changing law of freezing temperature field in ultra-long subway communication chan-nels,it can predict and analyze the development of freezing temperature field in strata.This paper first studies the freezing design scheme of ultra-long subway contact channel,analyzes the freezing effect,freezing construction difficulty and other aspects,and decides to adopt the construction scheme of double-sided tunnel installation of freezing units.According to the monitoring data,the feasibility of the soil freezing plan was verified.Finally,the numerical simulation analysis of the freezing temperature field was carried out,and ANSYS finite element soft-ware was used to build a model,and the simulation results were compared with the measured results on the con-struction site.The high degree of agreernent between the two verified the reliability of the finite element numeri-cal simulation analysis method,and the field temperature monitoring results showed that the freezing temperature field has the characteristics of phased development:in the first stage,the average cooling rate is 1.37℃/d,and the temperature difference between brine and soil layer is large,which makes the soil layer temperature drop rapidly;in the second stage,the cooling rate of soil reaches 0.90℃/d;in the third stage,the cooling rate slows down and drops to less than 0.5℃/d because the heat exchange tends to be balanced,so that the active freezing of the soil in the ultra-long contact channel is basically completed.The end of the active freezing period can safe-ly carry out the construction activities of the ultra-long contact channel.
subway tunnelsuper ultra-long communication channelfreezing methodfield monitoringnumerical simulation
万方数据
维普
