Numerical simulations of water flow and contaminants transport near mining wastes disposed in a fractured rock mass

Abstract

a b s t r a c tA numerical tool, called Hydro-Geosphere, was used to simulate unsaturated water flow and contaminants migration around an open pit filled with mining wastes. Numerical simulations had been carried out to assess the influence of various factors on water flow and solute transport in and around the surface openings including recharge, properties of the waste material and presence of fractures in the surrounding rock mass. The effect of the regional hydraulic gradient was also investigated. The analyses were conducted by simulating various 2D cases using experimentally obtained material properties and controlled boundary conditions. The effects of the hydrogeological properties of the filling material (i.e., water retention curve and hydraulic conductivity function), fracture network characteristics and conductivity of the joints were assessed. The results illustrate that fractures control water flow and contaminants transport around the waste disposal area. A fracture network can desaturate the system and improve the regional gradient effect.

Micro-damage evolution and macro-mechanical property degradation of limestone due to chemical effects

“…Formulas (4)- (6) show that limestone samples in this study undergoes different reactions in chemical environments, resulting in various degrees of porosity changes and skeleton softening.…”

“…This is because the presence of water often contains different chemicals, and the reaction between chemical icons with rock is a significant factor that accelerates failure progress, leads to mechanical characteristics decrease of rock, or causes geological disasters, such as land slope and earthquakes [2][3][4]. In underground storage constructions, such as nuclear waste storage [5,6] and underground reservoirs [7], the water has a significant influence on the stability of these underground constructions. Research on mechanical properties of chemical corroded rock is one of the important topics in ground water reservoirs, oil drilling, CO2 injection, toxic material or nuclear waste disposal, slope and dam foundation and underground rock engineering structures, etc.…”

Experimental investigation on the micro damage evolution of chemical corroded limestone subjected to cyclic loads

“…Engineering rocks are always surrounded by water, which is a significant influential factor for the mechanical characteristics of rocks by reducing their strength and even causing geological disasters during the excavation processes [4,5] . This is because that the surrounding water often contains chemical icons [6,7] , which can react with the mineral inside the rocks. Therefore, understanding the micro damage evolution of chemical corroded engineering rocks under cyclic loading conditions is vital in order to reduce the risk of causing potential engineering disasters during excavation.…”

A parallel-bonded chemical corrosion model for discrete element modelling of chemically corroded limestone

“…Numerical modelling of rock mechanics and rock engineering processes enables easier and detailed investigation and visualization of micro cracks, stress distributions and other variables [28][29][30][31][32]. Using extended finite element method (XFEM), Mohtarami et al, [33] conducted three-point and four-point bending tests on chemically corroded rock samples to investigate the crack propagation law.…”

“…The results show that the deformability of the sample increase with the growth of the chemical ions concentration; fracture toughness of the sample decrease with the growth of pH values of the solutions. Abdelghani et al, [34] This modelling approach which represents rock as an assemblage of particles (spheres, ellipsoids, blocks) that interact with each other, has been recognised as both a scientific tool and an engineering tool to investigate the mechanic properties of rock in both microscopic and macroscopic scales [35]. Bonded particle model (BPM), based on DEM, constitutes a dense packing of non-uniform sized circular or spherical particles [36].…”