复合岩土声发射试验研究

发布时间：2019-02-20 07:54

【摘要】：复合岩土材料广泛应用于矿山、交通等领域中的高边坡、排土场、尾矿坝等工程。复合岩土材料工程体量大，失效后果严重。复合岩土材料，具有多组份，各组份颗粒粒径相差悬殊，不均匀性高，材料整体变形大、强度低导致复合岩土工程（如排土场、高填方路基）破坏的不可预见性。为进行复合岩土工程安全状况的声发射监控，本文对多种复合材料的声发射进行了研究，具体内容如下：（1）总结了声发射技术的研究成果，分析了研究的现状和不足：目前国内外针对岩石材料的声发射特征有大量学者做了相关研究，但在土体声发射方面研究较少，进展缓慢，对复合岩土等复合材料的声发射更是缺乏理论研究。（2）对声发射基本原理进行了深入研究并归纳总结了声发射信号的基本处理方法。（3）设计了一系列复合材料的声发射实验，获得了复合岩土、石粉、石粉和石子、石膏和石子等复合材料的声发射特征，研究表明石粉材料与石粉和石子复合材料由于塑性变化呈不同的破坏特征。（4）通过不同塑性材料的对比研究，分析了塑性变化对材料声发射特征的影响。石粉材料塑性较强，声发射频率低，幅度小，特征不明显；石粉和石子复合材料在外荷载达到其破坏荷载的75%-80%时出现声发射大事件数急剧减少甚至消失的平静期现象；石膏和石子复合材料呈脆性破坏特征，受载初期即有声发射现象，并随荷载的增加声发射事件数增加，加载到破坏荷载的80%后，，声发射事件数加速增长直到破坏，但无声发射平静期。
[Abstract]:Composite rock and soil materials are widely used in high slope, dump, tailings dam and so on. The engineering volume of composite geotechnical materials is large and the failure consequence is serious. The composite geotechnical material has many components, the particle size of each component is different greatly, the inhomogeneity is high, the whole material is deformed and the strength is low, which leads to the unpredictability of the damage of composite geotechnical engineering (such as dump, high fill roadbed). In order to monitor the safety of composite geotechnical engineering, the acoustic emission of multiple composite materials is studied in this paper. The main contents are as follows: (1) the research results of acoustic emission technology are summarized. This paper analyzes the present situation and deficiency of the research: at present, a large number of scholars have done related research on the acoustic emission characteristics of rock materials at home and abroad, but the research on acoustic emission of soil is less, and the progress is slow. The acoustic emission of composite materials such as rock and soil is lack of theoretical research. (2) the basic principle of acoustic emission is deeply studied and the basic processing method of acoustic emission signal is summarized. (3) A series of acoustic emission experiments of composite materials were designed, and the acoustic emission characteristics of composite materials, such as composite rock and soil, stone powder and stone, gypsum and stone, were obtained. The results show that the failure characteristics of stone powder are different from those of stone powder and stone composite due to plastic change. (4) through the comparative study of different plastic materials, the influence of the plastic change on the acoustic emission characteristics of the materials is analyzed. Stone powder material has strong plasticity, low frequency and small amplitude of acoustic emission, and its characteristics are not obvious. When the external load of stone powder and stone composite material reaches 75% to 80% of its failure load, the number of large acoustic emission events decreases sharply or even disappears. Gypsum and stone composites show brittle failure characteristics, acoustic emission phenomenon occurs at the initial stage of loading, and the number of acoustic emission events increases with the increase of load. After loading to 80% of the failure load, the number of acoustic emission events accelerates until failure. But the silent launch lull.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU41

【相似文献】