Study on Multiparameter Precursory Information Identification of the Fracture of Yellow Sandstone

Table 2

Early warning table of body strain precursory information.

Numbering of rock samples	Peak stress (MPa)	Peak time (s)	Volume minimum strain (%)	Volume minimum strain time (s)	Precursory warning time (s)	Percentage of total time in advance (%)	Average value (%)
sz-17	103	1219	0.93	1080	139	11.4	11.4
sz-18	113	1316	1.04	1177	139	10.6
sz-20	105	1223	0.85	1085	138	11.3
sz-21	107	1270	0.85	1106	164	12.9
sz-22	106	1245	0.78	1103	142	11.4