不同粒径与矿物成分条件下黄砂岩的微观破坏
Microscopic failure of yellow sandstone with different-sized grains and mineral composition
何本国 1王杰 1张羽 2闫生存 3陈涛3
作者信息
- 1. Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines(Northeastern University),Shenyang 110819,China
- 2. Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines(Northeastern University),Shenyang 110819,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,China
- 3. Sichuan Huaneng Luding Hydropower Co.,Ltd.,Chengdu 610072,China
- 折叠
摘要
本文通过一系列室内试验研究了不同粒径与矿物成分对黄砂岩微观破坏的影响.地质薄片观察和SEM微观测试结果表明:石英和长石颗粒构成黄砂岩中的骨架,其他矿物则起到胶结物作用,将骨架颗粒粘合在一起.随着骨架颗粒粒径增加,黄砂岩抗压强度、弹性模量、抗拉强度、内聚力以及摩擦角减小.细粒黄砂岩的骨架颗粒比中粒黄砂岩的骨架颗粒更圆润致密,细粒黄砂岩的骨架颗粒含量最高,密度最大.相较与前者,粗粒砂岩呈现出骨架颗粒棱角分明、分布松散的特征.随着骨架颗粒粒径的增加,胶结物占比大幅上升;同时,石英(SiO2)占比迅速下降.黄砂岩破坏过程先从强度较低的胶结材料开始,接着进一步扩展到骨架晶粒.XRD矿物成分分析结果显示,黄砂岩的强度与骨架颗粒的石英含量有关,石英含量越高,强度越大.
Abstract
The effect of grain size on the microscopic failure of yellow sandstone was investigated via a series of laboratory experiments.The compressive strength,elastic modulus,tensile strength,internal cohesion,and friction angle of the sandstone are inversely proportional to the grain size.A combination of observation techniques(geological thin sections and scanning electron microscopy)indicated that the quartz and feldspar particles act as the skeleton in yellow sandstone,and the other minerals form the cement that bonds the skeleton particles together.The skeleton particles in fine-grained sandstone are rounder and more compact than those in medium-grained sandstone.Fine-grained sandstone has the highest content of skeleton particles and the densest.In contrast,coarse-grained sandstone exhibits particles that are more angular and loosely packed.As the grain size increases,the percentage of cementing material rises substantially.However,the percentages of SiO2 and quartz rapidly decrease.The failure process in the yellow sandstone initiates in the cementing materials that have lower strength.Shortly thereafter,the failure extends further to the skeleton grains.X-ray powder diffraction experiments suggest that the strength of yellow sandstone relates to the quartz content of the skeleton grains:the greater the amount of quartz,the greater the strength.
关键词
砂岩/粒径/力学试验/破裂模式/微观结构/矿物成分Key words
sandstone/grain size/mechanical test/failure mode/microscopic structure/mineralogical composition引用本文复制引用
基金项目
National Natural Science Foundation of China(52222810)
National Natural Science Foundation of China(52178383)
出版年
2023
NETL
NSTL
维普
万方数据