Study on Layered-Backfill-Based Water Protection Technology of Thick Coal Seam in the Ecologically Fragile Mining Area in Western China

Table 1

Summary of field testing results of the water-conducting fractured zone in the Yushen mining area and the adjacent mining areas.

Mining area		Coal mine	Working face length (m)	Depth of cover (m)	Mining method	Mining height (m)	Height of water-conducting fractured zone (m)	Fracturing-mining ratio
Yushen mining area	I	Jinjitan coal mine	300	229.6~262.1	Slice mining	5.5	110.14~143.37	20.03~26.07
			300	243.6~253.4	Full-height mining at one time	5.3~7.5	133.45~167.5	22.33~25.18
		Xuemiaotan coal mine	281.6	210	Fully mechanized mining	5.7	106–124	18.6~21.8
		Hanglaiwan coal mine	300	253	Slice mining	4.5	93.87~114.38	20.86~25.42
			300	230	Slice mining	5.0	110.3~124.8	22.06~23.51
		Caojiatan coal mine	360	269.8~273.4	Slice mining	6.0	136.1~139.15	22.68~23.19
		Yushuwan coal mine	255	284~291	Slice mining	5.0	117.8~135.4	23.56~27.08
	II	Jinjie coal mine	370	108~124	Fully mechanized mining	3.5	45.7	13.1
	III	Longde coal mine	300	201.04~202.80	Fully mechanized mining	3.96	69.4~76.85	17.53~19.41
		Xiaobaodang no.1 coal mine	350	295~310	Fully mechanized mining	5.8	152.01~158.78	26.21~27.38
Yuheng north mining area		Yuyang coal mine	200	182~216	Fully mechanized mining	3.5	84.8~96.3	24.0~27.5
Hujierte mining area		Bayangaole coal mine	260	610	Fully mechanized mining	5.3	126	23.7
		Menkeqing coal mine	300	689	Fully mechanized mining	4.7	110	23.4