Hydrological Characteristics of Ordovician Karst Top in a Deep Region and Evaluation of Its Threat to Coal Mining: A Case Study for the Weibei Coalfield in Shaanxi Province, China

Table 4

The depth of floor failure and main control factors in the study area.

No.	Working face	(m)	(m)	(m)
1	22506	96.0	0.7	11.8
2	22507	114.0	0.7	12.0
3	24504	140.0	0.1	13.5
4	24508	60.0	0.8	11.5
5	5208	150.0	0.6	12.0
6	5206	150.0	0.9	11.5
7	14503	136.4	0.5	13.6
8	13506	125.0	0.7	12.1