Quantitative Evaluation and Case Study of Risk Degree for Underground Goafs with Multiple Indexes considering Uncertain Factors in Mines

Figure 3

The single index measurement functions for evaluation indexes of underground goafs. The graphs (a), (b), (c), (d), and (e) show the functions of RQD, span, area, height, and buried depth, respectively. The graph (f) shows the function of rock mass structure, geological structure, groundwater, impact of groundwater, mining impact, condition of adjacent underground goaf, pillar size and layout, and engineering layout.

(a)

(b)

(c)

(d)

(e)

(f)