Effects of Different Conditions of Water Cooling at High Temperature on the Tensile Strength and Split Surface Roughness Characteristics of Hot Dry Rock

Table 4

Summary of test rules.

Influencing factors	Variable interval	Mass loss rate	Tensile strength	Height difference parameters		Texture parameters			Tensile strength and height MSE	Tensile strength and roughness coefficient
				Height MSE	Height fluctuation difference	Roughness coefficient	Roughness profile index	Roughness angle
Rock temperature	100–200°C	Not significant	Not significant	Not significant	Increased significantly	Not significant	Not significant	Not significant	Decreased significantly
	200–300°C
	300–400°C	Increased significantly	Decreased significantly	Increased significantly		Increased significantly	Increased significantly	Increased significantly
	400–500°C
	500–600°C	Relatively small	Relatively small	Relatively small		Relatively small	Relatively small	Relatively small
	Minimum	100°C	600°C	100°C	100°C	100°C	100°C	100°C
	Maximum	600°C	100°C	600°C	600°C	600°C	600°C	600°C
Water temperature	1–20°C	Decreased	Increased	Decreased	Decreased	Decreased	Decreased	Decreased	Relatively small decrease
	20–40°C
	40–60°C
	60–80°C
	Minimum	80°C	1°C	80°C	80°C	80°C	80°C	80°C
	Maximum	1°C	80°C	1°C	1°C	1°C	1°C	1°C
The number of heating-cooling cycles	1-2 times	Increased significantly	Decreased significantly	Relatively small	Relatively small	Relatively small	Relatively small	Relatively small	Relatively small decrease
	2-3 times
	3-4 times	Relatively small	Relatively small	Increased significantly	Increased significantly	Increased significantly	Increased significantly	Increased significantly
	4-5 times
	Minimum	1 time	5 times	1 time	1 time	1 time	1 time	1 time
	Maximum	5 times	1 time	5 times	5 times	5 times	5 times	5 times