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

Table 5

Ultimate span, ultimate deflection, and free subsidence space of overlying strata.

Layer number	Lithology	Limited span, ll (m)	Limited deflection, Wl (mm)	Height of free sinking space, ui (mm)
7	Glutenite	—	—	—
8	Coal	15.3	2.85	86
9	Sandy mudstone	31.3	1.23	986
10	Coal	17.4	3.56	1111
11	Sandstone	31.6	1.23	1374
12	Glutenite	21.9	2.22	1501