应力Lode角对砂岩变形特性影响

发布时间：2018-01-22 18:35

本文关键词： 岩石力学真三轴应力球应力偏应力变形应力Lode角　出处：《岩石力学与工程学报》2017年09期 　论文类型：期刊论文

【摘要】：基于自主研发的"多功能真三轴流固耦合试验系统",进行真三轴应力(σ1σ2σ3)条件下,保持球应力、偏应力不变而改变应力Lode角试验,研究了球应力、偏应力不变条件下,应力Lode角旋转对岩石变形特性的影响。结果表明:3个主应变、体应变及偏应变均随应力Lode角的变化而改变;偏应力相等时,ε1,ε2,ε3,εv及εs随着偏应力比M(q/p)的增大而呈现递减趋势;球应力相等时,3个主应变、体应变及偏应变随着偏应力比M的增大呈现先减小后增大的趋势,且在M较大时失稳破坏。岩石破坏时形成多个近似垂直于σ3方向而平行于σ1,σ2方向的破坏面,且强度值较常规加载明显偏小;偏应力比M对偏应变模量Gs有较大影响。球应力主要影响岩石的体积变化,且有一定的区间性;偏应力主要影响岩石的畸变,对岩石破坏起重要作用。试验砂岩的塑性变形受Lode角影响较大,塑形流动方向为θs=(θσ + π/2)。
[Abstract]:Based on the "multifunctional true triaxial fluid-solid coupling test system", the Lode angle of stress is changed under the condition of true triaxial stress (蟽 1 蟽 2 蟽 3). The influence of stress Lode angle rotation on the deformation characteristics of rock is studied under the condition of spherical stress and deflection stress invariant. The results show that the three principal strain, bulk strain and deflection strain all change with the change of stress Lode angle. When the deflection stress is equal, 蔚 _ 1, 蔚 _ 2, 蔚 _ 3, 蔚 _ v and 蔚 _ s decrease with the increase of the deviation stress ratio (M ~ Q / p). When the spherical stress is equal, the three principal strains, the bulk strain and the deflection strain tend to decrease first and then increase with the increase of the deflection stress ratio M. When M is larger than M, there are many failure surfaces perpendicular to 蟽 3 and parallel to 蟽 1 and 蟽 2, and the strength is obviously smaller than that of conventional loading. The deflection stress ratio M has a great influence on the deviant strain modulus Gs. The spherical stress mainly affects the volume change of rock and has certain interval property. Deformation stress mainly affects rock distortion and plays an important role in rock failure. The plastic deformation of the tested sandstone is greatly affected by the Lode angle, and the plastic flow direction is 胃 sn (胃蟽蟺 / 2).
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;重庆大学资源及环境科学学院;
【基金】：国家自然科学基金资助项目(51434003,51374256)~~
【分类号】：TU45
【正文快照】： 岩石在应力作用下的变形、强度等相关力学性质,一直是岩石力学试验研究的重点。但现有大量试验多是以圆柱体试样在轴对称应力(1?2?=3?)条件下进行的,因此忽略了中间主应力2?的影响,这与实际地应力状况不相符[1]。随着大量地下巷道、硐室、储油库、储气库及核废料库等的兴建,

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