块石胶结充填体声发射特征试验研究

发布时间：2018-04-29 06:42

本文选题：单轴压缩 + 块石胶结充填体　；参考：《江西理工大学》2015年硕士论文

【摘要】：声发射技术作为一种非接触式、实时、动态的监测手段已经在岩石、混凝土等材料中得到应用。但目前,运用声发射技术对块石胶结充填体稳定性方面进行的研究尚属罕见,而块石胶结充填采矿法作为现在矿山开采中的一种新型采矿方法已在矿山中得到进一步的应用。因此,对块石胶结充填体声发射特征进行研究并探究其失稳破坏的原因是十分有必要的。本文通过室内试验,运用b值和分形理论对块石胶结充填体失稳破坏的声发射特征进行处理、分析。主要研究结论如下:(1)声发射b值和关联分维值的上升代表着裂纹向着有序的方向发展,裂纹从小尺度扩展为大尺度,大尺度破坏占主导的地位;声发射b值和关联分维值的下降代表着裂纹发展呈现随机的、均匀的、无序的状态,裂纹以小尺度破坏为主,但在整个单轴压缩过程中变化复杂,没有统一的规律性,在破坏前没有明显的征兆。(2)块石胶结充填体的失稳破坏是由于两种介质变形不协调而发生剪切破坏,剪切面始终发生在胶结材料上而非块石,而且其他条件均未变,随着灰砂比的增加,块石胶结充填体的声发射现象越来越不明显。以上皆说明块石胶结充填体的声发射信号主要是来自于内部的胶结材料的破坏。(3)内部块石对裂纹的扩展起到了阻碍作用,导致块石胶结充填体的声发射b值和关联分维值不会单调变化,其变化非常复杂,试件破坏后难以形成完整的剪切面,其破坏形式为复杂的剪切破坏,难以找到明显的主裂纹。
[Abstract]:As a non-contact, real-time and dynamic monitoring method, acoustic emission technology has been applied in rock, concrete and other materials. But at present, it is rare to study the stability of cemented filling body with acoustic emission technology, and as a new mining method in mining, block cemented filling method has been further applied in mining. Therefore, it is necessary to study the acoustic emission characteristics of cemented rock filling and to explore the causes of instability and failure. In this paper, the acoustic emission characteristics of rock cemented filling are treated and analyzed by using b value and fractal theory through laboratory tests. The main conclusions are as follows: (1) the rise of AE b value and correlation fractal dimension value indicates that the crack develops towards the direction of order, the crack grows to a large scale at a small scale, and the large scale damage dominates. The decrease of acoustic emission b value and correlation fractal dimension value represents the random, uniform and disordered state of crack development. The crack is dominated by small scale failure, but the variation is complex in the whole uniaxial compression process, and there is no uniform regularity. There is no obvious sign before the failure. (2) the instability failure of the block cemented filling body is caused by shear failure due to the incongruity of the deformation of the two kinds of media, the shear plane always occurs on the cemented material and not on the block stone, and the other conditions have not changed. With the increase of the ratio of lime to sand, the acoustic emission of cemented filling body is less and less obvious. All these indicate that the acoustic emission signal of the cemented filling is mainly from the damage of the internal cementing material. As a result, the acoustic emission b value and the correlation fractal dimension of the cemented filling body do not change monotonously, but the change is very complex. It is difficult to form a complete shear surface after the failure of the specimen, and the failure form is complex shear failure, so it is difficult to find the obvious main crack.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD853.34

【参考文献】