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

Table 1

Basic parameters of coal samples.

Number of coal samples	Diameter (mm)	Height (mm)	Longitudinal wave velocity (mm/s)	Transversal wave velocity (mm/s)	Confining pressure (MPa)	Estimated axial strength (MPa)	Estimate elastic modulus (MPa)
XTT1	49.9	97.7	2063.00	1084.17	2	19.12	2761.15
XTT2	49.8	100.2	2088.28	1211.36	5	19.56	2804.56
XTT3	49.7	99.3	2139.89	1268.56	8	20.49	2903.88
XTT4	49.9	98.8	2161.90	1212.52	11	20.9	2950.62
XTT5	49.8	96.4	290.25	1330.02	14	21.44	3014.67
XTT6	49.8	97.4	2199.54	1151.45	17	21.62	3036.60
XHT7	49.9	95.6	2231.45	1241.22	20	22.25	3115.49