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

Table 4

Physical and mechanical properties of rock coal seam overlying strata of coal seam in Caojiatan coal mine.

No.	Lithology	Thickness (m)	Buried depth (m)	Bulk modulus (MPa)	Shear modulus (MPa)	Angle of internal friction (°)	Adhesion stress (MPa)	Tensile strength (MPa)
1	Loess	90	1900	—	—	—	—	—
2	Sandy mudstone	5	2570	3380	3150	39	5.6	5.9
3	Medium grained sandstone	10	2670	3830	3750	40	6.7	6.3
4	Fine grained sandstone	24	2700	3300	3160	32	6.5	6.8
5	Siltstone	15	2500	3600	3670	24	6.8	6.7
6	Medium grained sandstone	40	2100	3380	3150	20	5.6	6.8
7	Fine grained sandstone	16	2600	3300	3160	27	6.5	6.7
8	Medium grained sandstone	20	2500	3740	3570	24	6.3	6.8
9	Fine grained sandstone	32	2400	3600	3660	20	6.3	6.8
10	Siltstone	6	2500	3720	4630	24	8.6	5.7
11	2^−2 coal seam	12	1400	1480	1480	17	2.5	3.8
12	Siltstone	16	2500	3920	3700	23	8.5	5.5