Numerical analysis of the influence of dissolution pore structure on mechanical behavior of rock mass

Dissolution pores have a notable impact on the mechanical behavior of rock masses. Understanding the mechanisms by which dissolution pores influence the mechanics of rock is crucial for various engineering projects, including slope and foundation stability and related disaster mechanisms. Dissolved pores can be divided into two main types: honeycomb- and wormhole-like pores. In this study, a random algorithm was used to create discrete-element rock samples with different dissolution pore structures. Two characteristic dissolution parameters (rate of dissolution(k) and dissolution density coefficient (u)) were defined. They were used to describe the dissolution characteristics. We analyzed the internal stress, uniaxial compressive strength, crack propagation, and failure mode characteristics of the dissolved rock samples during the loading process. The results showed that rocks with different dissolution pore structures exhibit distinct mechanical behavior. Wormhole-like porous rock samples have higher uniaxial compressive strength and strength variability due to their different stresses. Furthermore, the uniaxial compressive strength of the dissolved rock is a function of the characteristic dissolution parameters. The deformation process of the porous dissolution sample was divided into four stages: (1) elastic deformation, (2) unstable fracture development, (3) post-peak strain softening, and (4) failure. Cracks in honeycomb-like dissolution rock were mainly initiated at the pore poles, and the failure mode was a shear failure, whereas cracks in the wormhole-like dissolution rock were mainly initiated at the pore poles and sidewalls, and the failure was rock crushing failure.