Determining the Height of Water-Flowing Fractured Zone in Bedrock-Soil Layer in a Jurassic Coalfield in Northern Shaanxi, China

Table 3

Physical and mechanical properties of the rock coal seam overlying the strata of the 5⁻² coal seam in Zhangjiamao coal seam.

No.	Lithology	The thickness (m)	The buried depth (m)	The density (g/cm^3)	Uniaxial compressive strength (MPa)	Modulus of elasticity (MPa)	Tensile strength (MPa)	Cohesion (MPa)	Angle of internal friction (°)
1	Loess	60	60	1620	700	600	0.2	0.32	20
2	Fine grained sandstone	10	70	2600	4500	3800	1.2	1.8	20
3	Sandy mudstone	6	76	2400	4000	3200	1.2	1.6	25
4	Siltstone	4	80	2400	4500	3800	1.2	1.8	20
5	Medium grained sandstone	6	86	2400	4000	3200	1.2	1.6	25
6	Fine grained sandstone	5	91	2600	4500	3800	1.2	1.8	20
7	Medium grained sandstone	12	103	2520	4000	3200	1.2	1.6	25
8	Fine grained sandstone	10	113	2600	6000	4800	1.5	1.9	34
9	Siltstone	16	129	2400	4000	3200	1.2	1.6	25
10	Fine grained sandstone	12	141	2600	5600	4200	1.5	1.9	28
11	Siltstone	18	159	2400	4500	3800	1.2	1.8	20
12	Medium grained sandstone	6	165	2520	4000	3200	1.2	1.6	25
13	2^−2 coal seam	5.5	170.5	1420	2000	1800	1.0	1.0	15
14	Fine grained sandstone	20.5	191	2600	5600	4200	1.5	1.9	28