Study on the Freeze-Thaw Problems in the Winter Construction of the Lianghekou Earth-Core Rockfill Dam and the Countermeasures for Prevention

Table 1

Statistical results of air temperature and the maximum frozen depth of the compacted gravelly soil without covering the thermal insulation materials.

Stage	Period	The number of days (day)				Frequency of the occurrence of negative air temperature (%)
		Total number of days (day)	Daily minimum air temperature (°C)
			0∼−3	−3∼−5	<−5
Stage 1	16/11/22–16/12/3	12	3	0	0	25
Stage 2	16/12/4–17/2/6	65	30	23	4	88
Stage 3	17/2/7–17/2/18	19	4	1	0	26
The maximum frozen depth of gravelly soil (cm)			14.2	16.0	19.7