Roof Bolting Anchoring Performance Research on the Entry under the Gob of Close-Distance Coal Seam

Table 1

Rock strata properties used in the numerical model.

No.	Lithology	Thickness (m)	(kg/m^3)	(MPa)	(MPa)	(MPa)	(MPa)	(deg)
1	Medium-fine sandstone	41	2535	4000	1500	3.00	3.50	35
2	Mudstone	10	2526	2500	1200	6.50	1.38	30
3	Sandy mudstone	3	2731	3340	3280	1.32	1.48	33
4	No.3-1 coal seam	4.8	1462	1500	1020	4.30	1.04	31
5	Mudstone	3-9	2526	2500	1200	6.50	1.38	30
6	No.3-2 mudstone	3.2	1462	1500	1020	4.30	1.04	31
7	Sandy mudstone	4	2738	1800	1100	2.00	2.50	28
8	Medium-fine sandstone	4	2731	6340	9280	4.23	3.48	33
9	Sandy mudstone	7	2731	3340	3280	1.32	1.48	33

Where is the average density of the rock strata, kg/m³. is the bulk modulus of the rock strata, MPa. is the shear modulus of the rock strata, MPa. is the tensile strength of the rock strata, MPa. is the cohesion of the rock strata, MPa. is the friction angle of the rock strata, deg.