Research on Cumulative Damage Characteristics of Rock Anchor Beam Concrete Supporting Structure by Blasting Vibration of Underground Powerhouse

Table 4

Relationship between the damage value of some unit monitoring points of rock anchor beams perpendicular to the axis of the powerhouse and the blasting times.

Monitoring points	Regression analysis	Confidence level
	Relationship between damage value (y) and blasting times (x)
S1	y = −0.0167x^3 + 0.1286x^2 − 0.1548x + 0.64	0.9957
S2	y = −0.05x^3 + 0.4143x^2 − 0.7357x + 0.56	0.9846
S3	y = −0.0667x^3 + 0.5786x^2 − 1.1548x + 0.64	0.9994
S4	y = −0.0167x^3 + 0.2357x^2 − 0.6476x + 0.44	0.9885