Abstract At present the design of frost-resistance fortification lengths of tunnels in cold regions mainly relies on engineering analogies and requires the known temperature field inside the tunnel. In order to clarify the design criteria for the fortification length and to solve the problem of no actual temperature data in the tunnel, the critical temperatures in the tunnel are proposed under two preconditions of no freezing in the drainage pipe of the lining layer and no frost heave in the surrounding rocks, based on the theoretical solutions to temperature fields of tunnels in cold regions, as well as the investigation data analysis and numerical analysis of the temperature fields in tunnel surrounding rocks; the influence of tunnel ventilation and surrounding rock conditions on the temperature field in the tunnel is analyzed and a regression formula for calculating the temperature in the tunnel is obtained depending on the inlet wind temperature, section dimension, wind velocity and initial rock temperature; furthermore, a method for calculating the frost-resistance fortification length of tunnels in cold regions is put forward. Taking the Shahukou Tunnel as an example and using the calculated frost-resistance fortification length of the tunnel, the effects of wind temperature and tunnel section size on the frost-resistance fortification length are analyzed. The results show that the fortification length gradually increases as the inlet wind temperature decreases, the inlet wind velocity increases and the section size increases, and gradually decreases as the temperature of the surrounding rock increases, respectively.
Abstract：
At present the design of frost-resistance fortification lengths of tunnels in cold regions mainly relies on engineering analogies and requires the known temperature field inside the tunnel. In order to clarify the design criteria for the fortification length and to solve the problem of no actual temperature data in the tunnel, the critical temperatures in the tunnel are proposed under two preconditions of no freezing in the drainage pipe of the lining layer and no frost heave in the surrounding rocks, based on the theoretical solutions to temperature fields of tunnels in cold regions, as well as the investigation data analysis and numerical analysis of the temperature fields in tunnel surrounding rocks; the influence of tunnel ventilation and surrounding rock conditions on the temperature field in the tunnel is analyzed and a regression formula for calculating the temperature in the tunnel is obtained depending on the inlet wind temperature, section dimension, wind velocity and initial rock temperature; furthermore, a method for calculating the frost-resistance fortification length of tunnels in cold regions is put forward. Taking the Shahukou Tunnel as an example and using the calculated frost-resistance fortification length of the tunnel, the effects of wind temperature and tunnel section size on the frost-resistance fortification length are analyzed. The results show that the fortification length gradually increases as the inlet wind temperature decreases, the inlet wind velocity increases and the section size increases, and gradually decreases as the temperature of the surrounding rock increases, respectively.
U Li1,
2 SUN Yuan1,
2 WANG Mingnian1 etc
.Research on the Calculation Method for Frost-Resistance Fortification Lengths of Tunnels in Cold Regions[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(4): 21-28
2021, Vol. 58 