The Establishment of Segmented Constitutive Relationship of Coal under Triaxial Compression: Take the No. 3 Coal of Xinhe Colliery as an Example

Table 2

Test results of Xinhe No. 3 coal samples under different confining pressure.

Confining pressure σ3 (MPa)	0	2	5	8	11	14	17	20
Peak value σs (MPa)	21.07	39.13	59.04	67.99	76.77	89.91	103.77	113.32
Peak strain εs (mm/mm)	0.00664	0.00879	0.01059	0.01103	0.01189	0.01277	0.01306	0.0137
Elastic modulus E (MPa)	2758	4472	5133	5876	6621	6763	6982	7173
Residual strength σr (MPa)	2.5	23	32.1	49.6	48.1	66.6	77.7	93.4