【作者】 钟宙灿；

【导师】 雷宛；

【作者基本信息】 成都理工大学 ， 应用地球物理， 2010， 硕士

【摘要】 锚杆施工属于隐蔽工程,肉眼不易察觉,它的质量受到地质界面、软弱地层等各种因素的影响,往往存在许多缺陷使施工质量难以满足设计要求,造成工程事故及重大经济损失。因此,采用恰当的方法检测锚杆的施工质量,防止工程事故的发生,成为当今锚杆工程中的重要问题。目前应用于锚杆检测的各种理论、检测手段都有不足之处,声频应力波无损检测技术作为一种既简便经济又迅速可靠的锚杆质量无损检测技术,成为了重要的研究方向。首先,本文介绍了锚杆锚固的结构及机理,基于弹性力学为基础的波动理论,简单介绍了声频应力波法在锚杆锚固体检测中的基本原理,得到了弹性波在锚杆锚固体系中衰减规律和能量分配规律,为锚杆锚固质量检测提供了理论依据。其次基于时频分析理论,在阐述各种方法基本原理的基础上,进行模型数据试验与效果分析,从中选取效果较好的分析方法。本文利用多道统计法对实测锚杆曲线进行子波提取分析;通过数值模拟锚杆合成记录,验证了该方法的可行性;并通过对锚杆模型曲线提取分析,得到了可靠结果。本文结合工程实际,通过时频分析方法对实测曲线进行分析,以验证该方法的可行性。本研究从不同锚固质量等级的锚杆中提取子波进行分析,得到不同锚固质量等级锚杆的子波形态,并利用子波合成模拟曲线验证判别结果,提高了判别精度,对锚杆锚固质量检测及评价具有重要意义。在完成本研究的过程中,作者发现通过时频分析方法及对锚杆实测信号进行子波提取分析是一项艰巨的工作,受到理论尚未完善等众多条件的限制,还存在一些不足,有待于做进一步的理论和试验研究。更多还原

【Abstract】 Anchor construction work is hidden, and its quality is not easily detected by the naked eye, and can be effected by the geological surfaces, soft ground and other factors. There are many defects in construction quality which make it difficult to meet the design requirements and make construction accidents and major economic losses. Therefore, using appropriate methods in detecting anchor quality and preventing construction accidents become important issues in the bolt work. Currently, a variety of theories and testing methods used in bolt test are inadequate. Sound frequency stress wave nondestructive testing technique as an easy and economical, fast and reliable of the nondestructive testing technology of anchor quality, has become an important research direction.Firstly, the article describes the structure and the anchoring mechanism based on elastic wave theory and introduces briefly the basic principle of sound frequency stress wave in anchorage bolt detect. We get the attenuation and distribution of energy of elastic wave in bolt anchoring system, which provides the theoretical basis for the detection of anchoring quality. Then, based on time-frequency analysis theory, we explain the basic principles of various methods, testing data and results analysis on the models, and have selected better analytical methods based on the results. In this paper, use multi-channel statistics on wavelet extraction of measured bolt curve and demonstrate the feasibility of the method by using one dimensional wave equation on the waveform modeling. The reliable results have been reached from our extraction analysis on the bolt curve.Base on the real engineering, it is validated to use the time-frequency analysis method to analyze the measured curve. This study has done wavelet extraction from different quality levels of anchor, has got wavelet patterns of different quality and grade of anchor bolt, and has discriminated validation results by using simulation curve of wavelet synthesis, has improved the identification accuracy, which is of importance to the detection and the evaluation of anchoring quality. Upon completion of this study, the authors found that using the time-frequency analysis method and wavelet extraction analysis from measured signal of the bolt curve is a difficult task due to the unperfected theory and many other conditions. There are still some shortcomings, which need further theoretical and experimental research.更多还原