A new shear creep damage model for rock masses after considering initial damage

Abstract

For a long time, one of the important safety problems in open-pit mines is the stability of a large number of high slopes with gently inclined soft interlayer. Rock masses formed after long geological processes generally have some initial damage. Mining works also cause varying degrees of disturbance and damage to rock masses in the mining area during the mining process. This phenomenon means that accurate characterization of the time-dependent creep damage for rock masses under shear load is necessary. The damage variable D is defined based on the spatial and temporal evolution laws of shear modulus and initial level of damage for the rock mass. In addition, a coupling damage equation between the initial damage of the rock mass and shear creep damage is established based on Lemaitre’s strain equivalence assumption. Kachanov’s damage theory is also incorporated to describe the entire process of time-dependent creep damage evolution for rock masses. A creep damage constitutive model that can reasonably reflect the actual mechanical properties of rock masses under multi-stage shear creep loading conditions is established. This takes into account multi-stage shear creep loading conditions, instantaneous creep damage during the shear load phase, staged creep damage and factors influencing the initial damage of rock masses. The reasonableness, reliability and applicability of this model are verified by comparing the results of the multi-stage shear creep test with calculated values from the proposed model. As opposed to the traditional creep damage model, the shear creep model established in this present study takes into account the initial damage of rock masses and can describe the multi-stage shear creep damage characteristics of rock masses more convincingly.

Constitutive Model for Grouted Rock Mass by Macro-Meso Damage

“…The Lemaitre assumption was proposed by French scholar Roger Lemaitre in 1982. Since then, the Lemaitre assumption has been widely used in the fields of geotechnical engineering and material mechanics [ 44 , 45 , 46 ]. Figure 1 illustrates a rock containing both macroscopic and microscopic defects, a rock containing only macroscopic defects, a rock containing only microscopic defects and a virtual rock without damage at all.…”

Effectiveness and reversibility test of electrochemical modification of mudstone hydro-mechanical parameters

“…It is evident that mudstone interlayers in open-pit mines play a crucial role in controlling slope stability Solving the stability problems of weakly interbedded slopes is of great significance to engineering practice. However, due to the unique properties of mudstone, reinforcing mudstone in engineering contexts presents significant challenges and has become a hot issue in the field (Hu et al, 2023). Currently, control measures for mudstone in engineering practice mainly include physical and chemical methods.…”