In Situ Test Study of Characteristics of Coal Mining Dynamic Load

Figure 4

Shockwave and frequency spectrum features in Test 1.

(a) Channel 7 distance = 452.5 m

(b) Channel 6 distance = 498.7 m

(c) Channel 4 distance = 538.8 m

(d) Channel 11 distance = 871.5 m

(e) Channel 14 distance = 938.1 m

(f) Channel 13 distance = 1053.1 m

(g) Channel 8 distance = 1458.1 m

(h) Channel 9 distance = 2125.7 m