Multiscale Pore Damage Evolution and Self-inhibition Mechanism in Rock under Dynamic Impact: A Coupled Statistical Constitutive Model Integrating Loading Effects

Haicheng She^1,2,3Yanxu Liang^4*Siqi Liu⁴Zaiqiang Hu³

• ¹Yangtze University, Jingzhou, China
• ²Key Laboratory of Drilling and Production Engineering for Oil and Gas, Wuhan, China
• ³Institute of Geotechnical Engineering, Xi’an University of Technology, Xi’an University of Technology, Xi’an, China
• ⁴School of Urban Construction, Yangtze University, Jingzhou, China

To reveal the damage evolution law of the rock under the action of different numbers of impacts, impact disturbance, scanning electron microscopy, nuclear magnetic resonance, and triaxial compression tests were carried out. The relationship between the energy spectrum area and porosity was determined. Combining the Weibull distribution and the Drucker-Prager intensity criterion, a rock statistical damage model and a constitutive model considering impact disturbance were established. Research has shown that: (1) With the increase of impact times, different types of pores increased. Among these, the increase in mesopores and macropores was relatively greater than that in micropores. The porosity and expansion rate both increased significantly. However, their growth rate slowed down with the increase in impact times. This indicates that mesopores and macropores had a buffering effect on the impact of the disturbance effect. (2) As the number of impacts increased, the initial shear strength decreased rapidly. Indicating that the disturbance development of pores and cracks had a significant deterioration effect on the mechanical properties of rocks. Subsequently, the decrease in shear strength slowed down. Indicating that the growth and development of pores and cracks also had an inhibitory effect on impact disturbance.