初始损伤对脆性岩石抗压力学性质的影响

发布时间：2018-01-26 21:10

本文关键词： 岩石损伤单轴抗压强度弹性模量脆性破坏　出处：《中南大学学报(自然科学版)》2017年02期 　论文类型：期刊论文

【摘要】：基于现有各向同性损伤本构理论,提出岩石初始损伤定义及其计算方法。初始损伤表示为加载前的损伤岩石弹性模量相对无损岩石弹性模量的劣化程度。对不同初始损伤的玄武岩试样进行单轴抗压试验,定量分析初始损伤对玄武岩的应力与应变关系、强度、破坏应变、初始泊松比和应变软化性质等的影响,给出单轴抗压强度、初始泊松比等力学参数随初始损伤变量变化的规律及拟合公式。研究结果表明:只有当岩石初始损伤超过损伤门槛值即无损岩石破坏时对应的损伤值时,岩石抗压强度随初始损伤增大而显著减小;与峰值应力对应的应变随初始损伤增大而近似呈线性增大趋势;岩石初始泊松比随初始损伤增大近似呈指数增大;初始损伤越小,应力峰值后的岩石破坏越显脆性。
[Abstract]:Based on the existing isotropic damage constitutive theory. The definition of initial damage of rock and its calculation method are put forward. The initial damage is expressed as the deterioration degree of elastic modulus of damaged rock before loading. Uniaxial resistance of basalt samples with different initial damage is carried out. Pressure test. The effects of initial damage on stress and strain relationship, strength, failure strain, initial Poisson's ratio and strain softening properties of basalt are quantitatively analyzed, and uniaxial compressive strength is given. The variation of initial Poisson's ratio with the initial damage variable and its fitting formula. The results show that only when the initial damage exceeds the damage threshold is the corresponding damage value of non-destructive rock. The compressive strength of rock decreases significantly with the increase of initial damage. The strain corresponding to the peak stress increases linearly with the increase of initial damage. The initial Poisson's ratio increases exponentially with the increase of initial damage. The smaller the initial damage, the more brittle the rock failure after the peak stress.
【作者单位】：中南大学土木工程学院;湖南理工学院土木建筑工程学院;
【基金】：国家自然科学基金资助项目(51308210)~~
【分类号】：TU45
【正文快照】： 受地质构造运动、温度等外部因素的影响,天然岩石一般为内部含孔隙和裂纹等缺陷的材料。这些缺陷所在部位往往容易产生应力集中,从而影响岩石的宏观力学性质。目前,损伤力学理论是研究岩石力学行为的成熟理论,根据该理论,若将岩石内部既有缺陷看作初始损伤,则工程岩体内部的各

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