Effect of Shaft Pillar Extraction on Stability of Main Shaft: A Case Study at Xincheng Gold Mine, China

Table 6

Mechanical parameters of rock mass calculated according to Hoek-Brown criterion.

Shaft depth/m		GSI	UCS/MPa	D	Young’s modulus/GPa	Internal friction angle/°	Poisson’s ratio	Cohesion/MPa	Tensile strength/MPa
0–33.80	-	-	-	-	8.04	42	0.29	2.00	0.05
33.80–116.18	33	60	50.3	0	12.61	43.84	0.18	4.08	0.075
116.18–168.00	33	65	46.4	0	16.15	45.30	0.36	4.01	0.1
168.00–225.00	33	70	96.2	0	30.02	46.74	0.30	8.90	0.304
225.00–272.00	33	70	56.2	0	23.71	46.74	0.16	5.20	0.177
272.00–341.53	33	65	28.3	0	12.62	45.30	0.28	2.45	0.061
341.53–366.89	33	70	41.6	0	20.40	46.74	0.16	3.85	0.131
366.89–422.00	33	75	79.4	0	37.58	48.15	0.16	7.90	0.365
422.00–465.50	33	75	78.9	0	37.46	48.15	0.18	7.85	0.363
465.50–529.74	33	60	63.5	0	14.17	43.84	0.24	5.14	0.094
529.74–663.20	30	70	123.8	0	31.62	45.94	0.34	11.19	0.43

Intact rock core cannot be obtained in the stratum from 0 to 33.8 m beneath the surface.