【摘要】 矿井采空区煤矸石充填体长期处于高湿度和硫酸盐环境中，受采动诱发的高应力作用影响，易出现强度退化与早期损伤累积。为改善其承载能力和耐久性能，采用纤维增强复合材料(FRP)对煤矸石充填体进行约束是一种有效途径。通过单调轴压试验和声发射(AE)监测研究了不同工况、FRP层数、应力比和作用时间等因素对FRP约束煤矸石充填体应力-应变关系及AE响应的影响规律，剖析了裂纹模式及b值等损伤演化机理。结果表明：硫酸盐及高应力作用后，试件应力-应变曲线第一阶段的弹性模量较未劣化状态提高了21.78%～24.2%,而极限应变降低了7.95%～38.56%;AE能量演化主要分为弹性变形、裂纹稳定扩展、裂纹非稳定扩展及破坏4个阶段；随着应力比的增大，试件初始损伤程度升高，裂纹扩展速率加快，且轴压后期剪切裂纹的累计占比逐渐上升，b值呈断崖式下降；基于AE参数并结合混凝土微单元服从Weibull分布的假设，建立了硫酸盐及高应力作用下FRP约束煤矸石充填体的损伤因子演化模型。更多还原

【Abstract】 The coal gangue filling body in goaf areas is long-term exposed to a high humidity and sulfate environment, and meanwhile, it is also affected by the high stress induced by mining activities. Consequently, it is prone to strength degradation and early damage accumulation. To improve its load-bearing capacity and durability, using fiber-reinforced polymer(FRP) to confine the coal gangue filling body is an effective approach. In this study, monotonic axial compression tests combined with acoustic emission(AE) monitoring were conducted on FRP-confined coal gangue concrete specimens, in the hope of grasping the influences of different working conditions, numbers of FRP layers, stress-to-strength ratios, and exposure times to their stress-strain behavior, AE response, crack pattern, and b-value evolution. On this basis, the underlying damage evolution mechanisms were elucidated through fracture mode identification and b-value analysis. The results indicate that after exposure to a sulfate and high-stressenvironment, the elastic modulus of the specimens in the first stage of the stress-strain curve increases by 21.78%-24.2%, while the ultimate strain decreases by 7.95%-38.56%, compared with the unexposed specimens. The AE energy evolution can mainly be divided into four stages, i.e., elastic deformation, stable crack propagation, unstable crack growth, and final failure. As the stress-to-strength ratio increases, the initial damage of the specimens intensifies, contributing to quicker crack propagation. Moreover, the cumulative proportion of shear cracks gradually grows in the later stage, and the b-value exhibits a cliff-like drop. Ultimately, a damage evolution model for FRP-confined coal gangue concrete under sulfate and high-stress conditions was developed based on the AE parameters and the assumption of Weibull distribution.更多还原