摘要:
水岩作用是深部地下工程围岩损伤失稳的重要诱发因素。采用单轴压缩试验、数字图像相关技术及微观结构测试，研究在不同溶液长期浸泡下变粒岩力学性质、局部损伤及微观结构的变化规律，探讨水岩作用对力学特性与损伤演化规律的影响机制。结果表明：随着浸泡时间的增长，变粒岩的弹性模量和单轴抗压强度非线性降低，相应的劣化度非线性增加；矿井水条件下力学性质的劣化程度高于蒸馏水条件，但浸泡150 d后两者差距可以忽略。随着轴向加载的进行，应变场经历从均匀化到局部化再到破裂的过程，局部损伤发育水平逐渐升高，表现为损伤强度因子非线性增大、峰值应力后剧增，而损伤局部化因子波动性减小、峰值应力后持续下降。同时，水岩作用对局部损伤发育具有促进作用，峰值应力处的损伤发育水平随浸泡时间的增长而升高，矿井水的促进作用更明显。此外，变粒岩内水敏性物质与溶液发生水岩反应，造成孔隙发育，孔径增大，微观结构趋于破碎，且矿井水对微观结构的劣化更显著。
Abstract:
Water-rock interaction is a crucial inducing factor for the damage and instability of surrounding rocks in deep underground engineering. Using the uniaxial compression test, digital image correlation technology, and microstructure test, this study investigated the changes in the mechanical properties, local damage, and microstructures of granulite subjected to long-term immersion in different solutions. The influence mechanisms of water-rock interaction on the mechanical properties and damage evolution were discussed. The results indicate that with increasing immersion time, both the elastic modulus and uniaxial compressive strength decrease nonlinearly, while the corresponding deterioration degrees increase nonlinearly. The deterioration of mechanical properties in mine water is more serious than that in distilled water; however, the difference can be neglected after soaking for 150 d. With the progress of axial loading, the strain field undergoes a process from homogenization to localization and to fracture. The development level of local damage rises gradually accompanied by a nonlinear increase in the damage severity factor and a rapid increase after the peak stress, and a fluctuant decrease in the damage localization factor and a constant decrease after the peak stress. Meanwhile, the water-rock interaction exerts a promoting effect on the development of local damage. The development level at the peak stress rises with the increase of immersion time, and the effect of mine water is more obvious. In addition, the water-sensitivity substances in granulite react with the solutions, resulting in the development of pores, the increase of pore sizes, and the fragmentation of microstructures. The microstructures in mine water are more visibly deteriorated.
百度学术
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