The propagation and interaction of multiple cracks induced by freezing in rock

Abstract:

The freeze-thaw damage of fractured rock mass frequently triggers hazards in cold region. This requires comprehensive understanding the processes of rock deformation and cracking under freezing conditions, as well as their impact on the stability of infrastructures. This work investigates the propagation and interaction of multiple cracks induced by frost expansion pressure using TOUGH- AiFrac based modelling and physical experiments. In TOUGH-AiFrac, the rock deformation and cracking are modeled using AiFrac, while heat transfer and water-ice phase change are modeled using the extended TOUGH2. In order to have a better understanding of frost cracking mechanisms in fractured rock, a series laboratory experiment is designed to explore the crack propagation and coalescence under freezing temperature. The numerical model is also performed to reproduce the fracture path observed in laboratory experiments in an effort to improve process understanding and to develop predictive tools. The experimental and numerical results indicate that the stress shadow between double cracks also has significantly impact on the damage pattern (see Fig. 1).