Research on Cooling Effect of Ice Cube Assisted Method in High Ground Temperature Tunnel Construction Period

In order to solve the problem of heat damage in high ground temperature tunnel construction environment, the cooling effect of ice cube assisted method is studied and its design parameters are determined. Based on the Chengkun Railway Baoangying tunnel project, the numerical model is verified by field measured data and was used to conduct an in-depth analysis of the influence of different ice shapes and arrangements on the temperature field distribution of different cross-sectional locations in high ground temperature tunnels. The results show that: compared with pure mechanical ventilation, the temperature of each section is significantly lower and the temperature difference between sections is significantly reduced with the aid of ice blocks. The cooling speed of wall-shaped ice blocks arranged in double-sided is the fastest, about 20% faster than the cube shape, and the double-sided arrangement is about 15% faster than the single-sided arrangement. When the amount of ice is the same, the correlation between the tunnel temperature and the shape and arrangement of ice blocks after 30 min of ventilation is not significant, and the role of ice blocks is mainly to cool the fresh air heated by the surrounding rock and maintain its temperature, the tunnel temperature is mainly determined by ventilation temperature.