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Study on Anti-Freezing Parameters of High-Altitude Tunnels in Western Sichuan Based on Field Tests
(1 China Railway Southwest Research Institute Co., Ltd., Chengdu 611731; 2 Sichuan Provincial Engineering Technology Research Center of Tunnel Safety, Chengdu 611731; 3 Sichuan Highway Planning, Survey, Design and Research Institute Ltd., Chengdu 610041;4 China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031)
Abstract In view of design parameters of anti-freezing and thermal insulation for high-altitude tunnels in West? ern Sichuan Plateau, based on the measured longitudinal temperature data of 10 typical high-altitude tunnels in Western Sichuan, this paper studies the longitudinal temperature characteristics and anti-freezing parameters of high-altitude tunnels in Western Sichuan. The research results show that the longitudinal temperature distribution inside operational tunnels on the Western Sichuan Plateau can be divided into three types: cut-through, weakly symmetrical and asymmetrical; the longer the length of high-altitude tunnels is, the greater the temperature difference between the tunnel portal and the tunnel inside will be in winter season, and the maximum temperature difference inside and outside tunnels in winter is linearly related to the length of the tunnels on the Western Sichuan Plateau;based on the temperature data measured at tunnel portals, this paper puts forward an empirical formula for calculation of the thickness of the thermal insulation layer laid at tunnel portal sections on the Western Sichuan Plateau;combined with parameters such as air temperature and winter wind speed at the portal, this paper conducts a comprehensive analysis of the length of the thermal insulation layer setup at the tunnel portal sections and proposes the empirical formula for calculation of the length of thermal insulation layer laid at the portal sections of long or extralong tunnels on the Western Sichuan Plateau; in terms of the design of the thermal insulation layers at the portal sections of tunnels on the Western Sichuan Plateau, dynamic design methods shall be adopted, and if conditions permit,it should be amended according to the measured longitudinal temperature data after completion of tunnel construction.
Abstract：
In view of design parameters of anti-freezing and thermal insulation for high-altitude tunnels in West? ern Sichuan Plateau, based on the measured longitudinal temperature data of 10 typical high-altitude tunnels in Western Sichuan, this paper studies the longitudinal temperature characteristics and anti-freezing parameters of high-altitude tunnels in Western Sichuan. The research results show that the longitudinal temperature distribution inside operational tunnels on the Western Sichuan Plateau can be divided into three types: cut-through, weakly symmetrical and asymmetrical; the longer the length of high-altitude tunnels is, the greater the temperature difference between the tunnel portal and the tunnel inside will be in winter season, and the maximum temperature difference inside and outside tunnels in winter is linearly related to the length of the tunnels on the Western Sichuan Plateau;based on the temperature data measured at tunnel portals, this paper puts forward an empirical formula for calculation of the thickness of the thermal insulation layer laid at tunnel portal sections on the Western Sichuan Plateau;combined with parameters such as air temperature and winter wind speed at the portal, this paper conducts a comprehensive analysis of the length of the thermal insulation layer setup at the tunnel portal sections and proposes the empirical formula for calculation of the length of thermal insulation layer laid at the portal sections of long or extralong tunnels on the Western Sichuan Plateau; in terms of the design of the thermal insulation layers at the portal sections of tunnels on the Western Sichuan Plateau, dynamic design methods shall be adopted, and if conditions permit,it should be amended according to the measured longitudinal temperature data after completion of tunnel construction.
ZHENG Bo1,
2 WU Jian1,
2 ZHENG Jinlong3 KUANG Liang4 GUO Rui1 etc
.Study on Anti-Freezing Parameters of High-Altitude Tunnels in Western Sichuan Based on Field Tests[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(5): 30-36
2021, Vol. 58 