基于粒径差异性的粗砂岩强度参数特征分析  

Analysis on Strength Parameters of Coarse Sandstone Based on Particle Size Difference

作　　者：谢良甫[1,2] 刘晓东 张家兵 祝清阳 XIE Liangfu;LIU Xiaodong;ZHANG Jiabing;ZHU Qingyang(School of Civil Engineering and Architecture,Xinjiang University,Urumqi,Xinjiang 830046,China;Xinjiang Civil Engineering Technology Research Center,Urumqi,Xinjiang 830046,China)

机构地区：[1]新疆大学建筑工程学院,新疆乌鲁木齐830046 [2]新疆土木工程技术研究中心,新疆乌鲁木齐830046

出　　处：《矿业研究与开发》2022年第1期120-126,共7页Mining Research and Development

基　　金：国家自然科学基金青年科学基金项目(51908482);国家自然科学基金地区科学基金项目(52068066);新疆维吾尔自治区高校科研计划项目(XJEDU2018Y008)。

摘　　要：为探究粒径差异性对粗砂岩抗压强度、弹性模量、泊松比、裂纹演化的影响规律与关联程度,以室内试验为基础,采用颗粒流数值模拟软件PFC3D进行参数标定获取岩体合理细观参数,建立不同水平粒径比模型并进行单轴压缩模拟试验,分析基于粒径差异性的粗砂岩各参数的变化规律,并通过灰色关联模型定量分析粒径比与粗砂岩力学参数的相关性。结果表明:粒径比由2.0增至5.0,岩体抗压强度降低了29.93%,弹性模量降低了17.20%,泊松比增大了5.69%。根据裂纹演化规律将其分为第一区间(2.0≤r≤3.0)、第二区间(3.0<r≤4.0)、第三区间(4.0<r<5.0),张拉与剪切裂纹数均与粒径比表现为负相关,剪切裂纹变化趋势为第三区间<第二区间<第一区间;张拉裂纹在第一区间内浮动较大,第二、三区间变化趋势相近。破坏模式的影响分析表明,粒径比较小时模型内粒径差异性较弱,颗粒分布较为均匀,颗粒之间形成的黏结接触面积较小,其抵抗黏结作用所产生的变形较弱,颗粒粒径对裂纹在延展方向上的影响作用较弱,此时模型多发生剪切破坏。灰色关联模型数据显示,与粒径比关联度最大的为泊松比,最小的为剪切裂纹数,其值分别为0.575和0.519,在试验中充分考虑粒径比的差异性,有助于合理调控与获取粗砂岩岩体的相关力学参数。In order to explore the influence law and correlation degree of particle size difference on compressive strength,elastic modulus,Poisson’s ratio and crack evolution of coarse sandstone,based on laboratory tests,the particle flow numerical simulation software PFC3 D was used to calibrate parameters to obtain reasonable mesoscopic parameters of rock mass.Models with different horizontal particle size ratio were established and uniaxial compression simulation experiments were carried out.The variation laws of parameters of coarse sandstone based on particle size difference was analyzed.The correlation between particle size ratio and mechanical parameters of coarse sandstone was quantitatively analyzed by grey correlation model.The results show that,with the increase of particle size ratio from 2.0 to 5.0,the compressive strength of rock mass decreases by 29.93%,the elastic modulus decreases by 17.20%,and the Poisson’s ratio increases by 5.69%.According to the crack evolution law,it is divided into the first interval(2.0≤r≤3.0),the second interval(3.0<r≤4.0),and the third interval(4.0<r<5.0).The numbers of tension and shear cracks are negatively correlated with the particle size ratio,and the change trend of shear cracks is the third interval<the second interval<the first interval.Tension cracks float larger in the first interval,and have similar trends in the second and third intervals.Analysis on the impact of failure modes shows that,when the particle size is small,the particle size difference in the model is weak,the particle distribution is relatively uniform,the bonding contact area formed between particles is small,and the deformation caused by the resistance to bonding is weak.The influence of particle size on the crack in the extension direction is weak,and at this time,the model is prone to shear failure.Grey correlation model data shows that Poisson’s ratio has the largest correlation with particle size ratio,and shear crack number has the smallest correlation,the values are 0.575 and 0.519,res

关 键 词：粒径比 数值模拟 裂纹演化 破坏模式 灰色关联模型 

分 类 号：TD313[矿业工程—矿井建设] TU452[建筑科学—岩土工程]