Numerical investigation on the mechanical behaviour of combined backfill-rock structure with KCC model

摘要

To ensure safe and economic backfilling of mined-out area, a key issue is to understand the mechanical response of the backfill-rock interaction system. In this study, the Karagozian-case concrete (KCC) model is adopted to numerically evaluate the uniaxial compression behaviour of combined backfill-rock structure (CBRS). A detailed step-by-step procedure for calibrating the KCC model parameters (e.g., strength surface, equation of state and damage parameters) of backfill is presented, and the feasibility of calibrated parameters is verified against the reported triaxial compression test with various confining pressures on cemented tailings backfill (CTB) and Brazilian indirect tensile test. The input parameters of rock material are determined based on the reported material property together with the auto-generation function in the KCC model. After that, the effect of backfill inclination on the damage initiation and propagation, stress distribution, stress-strain response and energy evolution of CBRS are comprehensively investigated. The numerical results provide further insights on the stability of backfill-rock system, thus contributing to a more rational and economic design of stable backfill structures. (C) 2021 Elsevier Ltd. All rights reserved.