Freezing Design Optimization of Long?distance Contact Channel ofShield Tunnel
About the author:
China Electric Power Construction （Guangzhou） Rail Transit Construction Co., Ltd., Guangzhou,Guangdong 510330, China
Abstract:
Long?distance contact channel freezing soil range is huge, the freezing cycle is long, at thesame time, the excessive frost heaving and thaw settlement displacement needs a lot of tracking groutingreinforcement, the construction cost is high, and the chemical additives in the grouting material maycause groundwater pollution. Therefore, based on the contact channel project of Zhengzhou Subway Line8, a heat?force coupling three?dimensional calculation model is established, according to the calculationresults of temperature field and displacement field, the freezing design optimization measures of thecontact channel are proposed. It can achieve more accurate formation reinforcement control, avoidexcessive thaw settlement grouting, and improve economic and environmental benefits. The researchresults show that by reducing the dispersion angle of the freezing pipes at the top and bottom of the contactchannel arch, the thickness of the freezing wall can be reduced during the freezing process, so as toreduce the frost heaving displacement, and at the same time, it can ensure the effective thickness of thefreezing wall and the frozen soil average temperature.
