Experimental Study on the Property Degradation and Failure Mechanism of Weakly Cemented Sandstone under Dry-Wet Cycles

Table 2

Acoustic emission parameter information during the destruction of weakly cemented sandstone.

Acoustic emission parameters	Precursor feature	Number of dry-wet cycles	Corresponding critical relative stress value (%)	Comprehensive critical relative stress value (%)
Event rate	The event rate appeared to be close to 0 before the rupture, and then the platform oscillated, followed by a sudden rise.	N = 0	94	95
		N = 5	95.6
		N = 10	95.5
b value	The b value before the rupture suddenly drops, and the concentration range of the b value is 0.32∼0.41.	N = 0	96
		N = 5	95.3
		N = 10	95.6
Entropy	The entropy value rises before rupture, and the concentration interval of entropy is 0.47∼0.58.	N = 0	96
		N = 5	96.2
		N = 10	96.7