Features and Constitutive Model of Gypsum’s Uniaxial Creep Damage considering Acidization

Table 1

Creep damage of gypsum rocks under different situations.

pH value	1^st stress level (32 MPa)	2^nd stress level (38.4 MPa)	3^rd stress level(44.8 MPa)
7	No damage occurs	Damage occurs after loading for about 262.3 h	—
6	No damage occurs	Damage occurs after loading for about 242.7 h	—
5	Damage occurs after loading for about 180.6 h	—	—