A Damage Constitutive Model of Rock under Hydrochemical Cyclic Invasion

Abstract

In order to analyze the stability of water-related materials, the deterioration and damage of rock strength due to circulating water intrusion in an open tailings pond were studied. Uniaxial compression tests were carried out for rocks under different hydrochemical environments and varying numbers of invasion cycles. Results show that, with increasing number of cycle times, rock peak strength and elastic modulus gradually decrease and the acidity and alkalinity of the soaking solution also degrades rock strength. The curve of the number of cycles, acidity, alkalinity, peak strength, and elastic modulus is fit numerically. Based on the principle of damage mechanics, a hydraulic-chemistry-mechanics (HCM) coupling damage variable is defined. Based on the theory of microbody strength distribution, the constitutive equation for rock damage under the coupled effect of water chemistry and cyclic water invasion is established. The results verify the validity of the established damage constitutive model.

Chemical Corrosion-Water-Confining Pressure Coupling Damage Constitutive Model of Rock Based on the SMP Strength Criterion

“…By substituting Equations ( 5), ( 6) and (23) into Equation (15), the damage evolution equation of rocks under the coupling effects of chemical corrosion and load can be obtained, which is:…”

“…According to the model, nonlocal dilatation of the material close to the corrosion front determines the activation-controlled anodic dissolution [ 22 ]. Sun et al [ 23 ] defined the hydraulic chemistry-mechanics (HCM) coupling damage variable based on the law of damage mechanics and micro-strength distribution theory and established the constitutive equation for rock failure under the combination effect of hydration and cyclic water ingress. A time-dependent damage theory is presented by Borja et al [ 24 ] for rocks that have undergone solid dissolution and mechanical deformation.…”

Damage Characterization and Permeability Variation of Acidified Rock: A Theoretical and Experimental Study

“…Feng et al considered the stress damage of rheology when chemical solutions act on red sandstone, and optimized the rheological damage model for rock mass based on the generalized Kelvin model, the initial pH value of the solution, and time. Sun et al conducted mechanical property tests on rocks under different water chemical environments and different numbers of intrusion cycles, defined the HCM coupled damage variables, and established constitutive equations for rock damage under the coupled action of water chemistry and cyclic water intrusion based on the microbody strength distribution theory. In terms of permeability enhancement by acidification, Liu et al investigated the mechanism of acid sensitivity through different acid-treated core replacement tests with permeability variation as a quantitative indicator; they disclosed that the dissolution of minerals, generation of new precipitates, and migration of particles should be considered in evaluating the effect of acid on reservoirs.…”

“…Feng et al 14 when chemical solutions act on red sandstone, and optimized the rheological damage model for rock mass based on the generalized Kelvin model, the initial pH value of the solution, and time. Sun et al 15 conducted mechanical property tests on rocks under different water chemical environments and different numbers of intrusion cycles, defined the HCM coupled damage variables, and established constitutive equations for rock damage under the coupled action of water chemistry and cyclic water intrusion based on the microbody strength distribution theory.…”