摘要
获得脆性相似材料是开展岩体工程脆性破坏相似模拟试验的前提。为研究配比、胶结材料、颗粒级配等因素对相似材料强度和脆性的影响及控制机制,采用声发射、核磁共振仪、电镜扫描等开展了系统试验。结果表明:(1)常规砂-水泥-石膏胶结的相似材料中水泥的占比是控制材料强度的关键因素,但配比改变对相似材料脆性影响不大。(2)加入水玻璃和石灰胶结材料的试样压缩全过程声发射显著增多,加入石灰或改善材料中骨料的颗粒级配可有效提高相似材料的脆性。(3)改善骨料颗粒级配的相似材料其单轴压缩全过程曲线及声发射特征与脆性岩石压缩全过程演化曲线及声发射特征相似,是用以模拟岩石脆性破坏过程及声发射演化的理想材料。(4)通过核磁共振与电镜扫描分析不同相似材料孔隙及胶结特征可知,相似材料孔隙量与孔隙结构与材料脆性密切相关;胶结材料对骨料颗粒包裹情况是材料脆性的重要决定因素。研究成果对岩土工程相似模拟试验具有参考价值。
As obtaining brittle similar materials is the premise of carrying out the brittle failure similar simulative experiment of rock-mass engineering, the relevant systematical experiments are made with the methods of acoustic emission, nuclear magnetic resonance, electron microscope scanning, etc., so as to study the influences and the control mechanisms of the mixing ratio, cementing materials, particle gradation, etc. on the strength and brittleness of similar materials. The study results show that(1) the proportion of cement in the similar materials cemented with conventional sand-cement-gypsum is the key factor to control the material strength, but the change of the mixing ratio has little effect on the brittleness of similar materials;(2) the acoustic emission increases significantly during the whole compression process of the sample added with water glass and lime cementitious materials, but adding lime or improving the particle gradation of aggregate in the materials can effectively improve the brittleness of the similar materials;(3) the whole process curve and acoustic emission characteristics of uniaxial compression of the similar materials with improved aggregate gradation are similar to the evolution curve and acoustic emission characteristics of the whole compression process of brittle rock, thus the similar materials are the ideal materials to simulate the brittle failure process and acoustic emission evolution of the rocks;(4) through the analyses with nuclear magnetic resonance(NMR) and scanning electron microscopy(SEM) made on pore and cementation characteristics of different similar materials, it is found out that the pore volume and pore structure of the similar materials are closely related to material brittleness, while the wrapping of cementitious materials on aggregate particles is an important determining factor of the material brittleness. The study results can provide some references for the relevant similar simulative experiment of geotechnical engineering.
作者
余琪
陈世万
杨贵
刘家旭
叶建龙
田浪
YU Qi;CHEN Shiwan;YANG Gui;LIU Jiaxu;YE Jianlong;TIAN Lang;LI Jiahua(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,Guizhou,China;Key Laboratory of Karst Georesources and Environment of Ministry of Education(Guizhou University),Guiyang 550025,Guizhou,China)
出处
《水利水电技术（中英文）》
北大核心
2022年第9期210-220,共11页
Water Resources and Hydropower Engineering
基金
贵州省科学技术基金项目([2020]1Y185)
国家自然科学基金项目(4216020116)。
关键词
崩塌
物理模型
声发射
相似材料
脆性指数
rock mass collapse
physical model
acoustic emission
similar materials
brittleness index
