The Damage Constitutive Model of Shale Rock Based on Weibull Distribution and Its Verification

10.6911/WSRJ.202206_8(6).0107

Yingjie Wu

Shale rock ； Damage constitutive model ； Weibull distribution ； Confining pressure

World Scientific Research Journal

8卷6期（2022 / 06 / 01）

822 - 830

英文

With the increase of shale rock gas demand, the mining depth increases gradually and various safety accidents occur. Therefore, it is of great significance to study the constitutive behavior of shale rock under different confining pressures. Based on the existing constitutive model of rock, Weibull distribution function and confining pressure damage variable are introduced in this paper, combined with strain equivalence principle and Drucker‐Prager criterion, the damage constitutive model of shale rock under different confining pressures is established and parameter expression in damage constitutive model is determined. In the verification stage, the triaxial compression test results of shale rock under different confining pressures ( 10, 20, 30, 40, 50 and 60 MPa ) in the reference were carried out, and the results showed that: The theoretical curves of the damage constitutive model of shale rock under different confining pressures have the same trend as the test curves in the reference, indicating that the damage constitutive model constructed in this paper can better reflect the stress‐strain process of shale rock under triaxial compression. In the test process, if the stress decreases, the damage constitutive model cannot accurately reflect the stage of stress rising again. The damage constitutive model established in this paper can well fit the stress‐strain curves of elastic and plastic stages of shale rock under different confining pressures. The damage constitutive model constructed in this paper has certain reference value for deep shale rock excavation.