基于原子力显微镜的角砾岩微观力学性质研究

Research on Micromechanical Properties of Breccia based on Atomic Force Microscope

角砾岩破碎带是隧道施工中比较常见的不良地质现象,对于角砾岩多为宏观尺度上的力学性质研究,很少涉及微观尺度上的矿物力学特性。本文通过扫描电子显微镜(SEM)观测角砾岩矿物组成成分,借助原子力显微镜(AFM)获得矿物成分的杨氏模量,根据材料随机模型获得宏观杨氏模量。研究结果表明:角砾岩岩样的矿物组成和体积占比分别是:石英占比20%,钾长石占比40%,斜长石占比40%;AFM测出岩样中石英、钾长石、斜长石三种矿物的杨氏模量为99.13 GPa、91.78 GPa、63.36 GPa;角砾岩材料随机模型杨氏模量为81.20 GPa。本文提出一种基于原子力显微镜的微观岩石测试方法,测得角砾岩岩样的组成成分和微观力学性质,为从岩样中获得力学性质提供了一种新型的研究方法。

The breccia fracture zone is a common geological phenomenon in tunnel construction.The research on breccia is mostly the study of mechanical properties on the macro-scale,and rarely involves the mechanical properties of minerals on the micro and meso scale.In this paper,the mineral composition of breccia was observed by Scanning electron microscope(SEM),the Young′s modulus of the mineral composition was obtained with the aid of atomic force microscope(AFM),and the macro Young′s modulus was obtained according to the material random model.The results show that:the mineral composition and proportion of the breccia rock samples are:quartz accounts for 20%,potash feldspar 40%,and plagioclase 40%;the Young′s modulus of the three minerals of quartz,potash feldspar and plagioclase in the rock sample measured by AFM are 99.13 GPa,91.78 GPa,and 63.36 GPa;the Young′s modulus of the breccia model of random material is 81.20 GPa.This paper proposes a microscopic rock testing method based on atomic force microscope to measure the composition and micro-scale mechanical properties of breccia rock samples,providing a new research method for obtaining mechanical properties from rock samples.