裂隙岩体峰值后软化模型及时效性分析

工程岩体内部分布着不均匀的贯通和非贯通裂隙面，这些裂隙面存在的优势方位、间距、密度、力学特征等对岩体的力学性质和变形失稳破坏产生了显著影响，致使岩体表现出显著的软化和强烈的各向异性。这些微观和宏观裂隙的扩展贯通是诱发岩体变形失稳的重要因素。基于物理力学实验，研究岩石峰值荷载后的软化特征，考虑弹塑性与微裂隙损伤的耦合效应，探索更准确的岩石的弹塑性损伤模型。利用宏观裂隙岩体模型的物理模拟，采用断裂力学和损伤力学等对裂隙岩体破坏机制及时效变形进行研究，结合弹塑性损伤模型，并考虑宏观裂隙的断裂软化，探讨岩石弹塑性、微裂隙损伤演化及宏观裂隙断裂软化对裂隙岩体力学性质的影响，进而建立岩体塑性与断裂软化耦合的损伤断裂模型。进一步研究压缩荷载下裂隙岩体峰值后断裂软化的时效性。将研究成果应用于具体工程岩体，该研究有助于在复杂应力环境下工程裂隙岩体的变形失稳及长期稳定性进行评价。

The uneven and discontinuous cracks are often formed in the rock mass. The preferred orientation, spacing, density, and mechanical characteristics of cracks are the main factors influencing mechanical properties of rock mass, causing deformation and giving rise to instability of the rock mass, which makes the rock mass show a remarkable softening and strong anisotropy. Deformation and instability of the rock mass are linked with propagation and coalescence of microscopic and macroscopic cracks. Based on the physical and mechanical experiments, and the coupling between elastoplastic and micro-crack damage, the rock softening after the peak load is examined, and more accurate elastoplastic damage model is explored. The physical simulation of macro-crack rock model is carried out. Based on fracture mechanics and damage mechanics, the failure mechanism and aging deformation of fissured rock mass are researched. Combined with the elastoplastic damage model and fracture softening of the macro-crack, the effect of elastic-plasticity, micro-crack damage, and macro-crack fracture softening on mechanics properties of fissured rocks are analyzed, and the elastic-plastic fracture damage model of the coupling of plastic and fracture softening of rock mass are then established. The aging fracture softening of the fissured rocks under compressions is further investigated after the peak load. These research results are applied into engineering rock mass, which can help evaluate deformation, failure, and long-term stability of the fractured rocks in the environment of complex stress.