Experimental Investigation of Ground and Air Temperature Fields of a Cold-Region Road Tunnel in NW China

Table 2

Minimum negative temperature of testing sections.

Mileage	K30 + 663	K30 + 668	K30 + 683	K33 + 970	K33 + 990
Date	3/4	3/8	3/18	1/24	3/10
The lowest temperature (°C)	−3.2	−2.5	−0.9	−4.8	−3.3