Study on Overburden Stability and Development Height of Water Flowing Fractured Zone in Roadway Mining with Cemented Backfill

Table 4

Free subsidence space of overlying strata.

Layer number	Lithology	Layer thickness (m)	Residual crushing expansion coefficient, kci	Backfill space after compaction of fractured strata (mm)	Height of free sinking space, ui (mm)
12	Glutenite	4.2	1.03	126	1501
11	Sandstone	8.8	1.03	390	1374
10	Coal	2.5	1.06	540	1111
9	Sandy mudstone	15	1.06	1440	961
8	Coal	2	1.06	1501	61
7	Glutenite	21.97	1.03	—	—