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

Table 3

The relationship between the damage value of some unit monitoring points of the rock anchor beam along the axis of the powerhouse and blasting times.

Monitoring points	Regression analysis	Confidence level
	Relationship between damage value (y) and blasting times (x)
R1	y = −0.05x^3 + 0.3929x^2 − 0.5571x + 0.2	0.9838
R2	y = −0.05x^3 + 0.4214x^2 − 0.7286x + 0.36	0.9993
R3	y = −0.04x^3 + 0.0071x^2 + 0.2071x − 0.22	0.9964
R4	y = −0.0058x^3 + 0.0617x^2 − 0.0457x	0.9874
R5	y = −0.025x^3 + 0.2179x^2 − 0.4571x + 0.26	0.9860
R6	y = −0.02x^3 + 0.0214x^2 − 0.0786x + 0.06	0.9821