Damage Identification of Prefabricated Reinforced Concrete Box Culvert Based on Improved Fuzzy Clustering Algorithm and Acoustic Emission Parameters

Table 7

Crack data of four-component assembly box culvert in model test.

Load level (kN)	Loading/unloading	Crack number	Crack starting point (cm)	Crack width (mm)	Crack length (cm)
3.0	Loading	—	—	—	—
6.0	Loading	—	—	—	—
9.0	Loading	1	(63.8, 0)	0.30	6.8
	Unloading	1	(63.8, 0)	0.04	6.8
12.0	Loading	1	(63.8, 0)	0.48	8.0
		2	(37.0, 0)	0.44	6.4
	Unloading	1	(63.8, 0)	0.18	8.0
		2	(37.0, 0)	0.30	6.4
15.0	Loading	1	(63.8, 0)	1.26	8.0
		2	(37.0, 0)	0.54	6.4
	Unloading	1	(63.8, 0)	0.59	8.0
		2	(37.0, 0)	0.28	6.4
18.0	Loading	1	(63.8, 0)	1.50	8.0
		2	(37.0, 0)	0.58	6.4
		3	(84.0, 0)	0.05	7.5
	Unloading	1	(63.8, 0)	0.72	8.0
		2	(37.0, 0)	0.28	6.4
		3	(84.0, 0)	0.03	7.5
21.0	Loading	1	(63.8, 0)	9.00	8.0
		2	(37.0, 0)	2.26	6.4
		3	(84.0, 0)	1.70	7.5
	Unloading	1	(63.8, 0)	5.10	8.0
		2	(37.0, 0)	1.08	6.4
		3	(84.0, 0)	0.73	7.5

The origin of the coordinates is set at the imaginary intersection point between the lower edge of the top plate and the outer edge of the side wall.