声波透射法在桩基检测中的理论与实验研究

发布时间：2018-10-20 13:46

【摘要】：随着现代社会经济建设的不断发展,桩基在建筑、领域的作用也日益凸显,然而桩基工程作为隐蔽工程,在施工过程中所受到的不确定性因素较多,桩基的安全性以及其施工的质量也越来越受到关注。超声透射法检测桩基能够迅速的、准确的、经济的发现缺陷位置、大小、类型等参数而得到广泛的应用。声波透射法检测桩基虽然已经是比较成熟的技术,但是缺少声波检测理论在桩基工程技术上的支撑。本论文主要从超声波对桩基完整性检测的理论、实验工程上的研究。1.基于对超声波的基本物理性质及在介质内部的基本传播特点,深入探讨和分析声波在混凝土桩基内部传播规律,详细评述不同参数如弹性模量、介质密度、粒径、发射频率等与声波衰减系数的关系,分析桩身内部存在不同缺陷时对声波透射系数的影响。通过对声波衰减、透射系数的研究建立声学参数和桩身缺陷的对应关系。2.在理论的基础上对混凝土桩基进行实验分析。利用工程试件模拟基桩缺陷实验,观察、分析基桩缺陷的检测曲线,根据不同类型的桩基缺陷有不同的声学特征,结合有关资料与检测实践,初步建立声学参数与缺陷类型的对应关系。绘制出判断桩身完整性的数据曲线,得出每种缺陷桩基对声波特性影响的规律性。实现了声波透射法在实验模拟上的缺陷分析,通过实验验证了声学检测桩基缺陷判别法的有效性,为超声波实测波形仅依靠声速和波幅进行判定的缺点,给工程中实测波形判定方法提供依据。3.基于声波透射法实验与理论,以辽宁省某跨海大道工程实例为检测对象,对其工程质量进行评测,利用声学判别法分析波速、幅值等因素,对桩基内部进行定性、定量分析,可以判断出桩内缺陷对桩身质量安全的影响程度。
[Abstract]:With the continuous development of modern social and economic construction, pile foundation plays an increasingly important role in the field of construction. However, pile foundation engineering, as a hidden project, is subject to many uncertain factors in the construction process. More and more attention has been paid to the safety of pile foundation and the quality of its construction. Ultrasonic transmission method is widely used to detect the location, size and type of defects. Although it is a mature technology to detect pile foundation by acoustic wave transmission method, it lacks the support of acoustic wave detection theory in pile foundation engineering technology. In this paper, the theory of ultrasonic testing of pile foundation integrity, experimental engineering research. 1. Based on the basic physical properties of ultrasonic wave and the characteristics of ultrasonic wave propagation in the medium, the propagation law of sound wave in concrete pile foundation is discussed and analyzed in depth, and the different parameters such as elastic modulus, medium density, particle size are discussed in detail. The relationship between the transmitting frequency and the attenuation coefficient of sound wave is analyzed. The influence of different defects in the pile body on the transmission coefficient of sound wave is analyzed. Through the study of acoustic attenuation and transmission coefficient, the corresponding relationship between acoustic parameters and pile body defects is established. 2. On the basis of theory, the experimental analysis of concrete pile foundation is carried out. Using engineering specimen to simulate foundation pile defect experiment, observe and analyze the testing curve of foundation pile defect, according to different kinds of pile foundation defect have different acoustical characteristic, combine relevant data and test practice, The corresponding relationship between acoustic parameters and defect type is established. The data curve of judging the integrity of pile body is drawn, and the regularity of the influence of each defect pile foundation on acoustic wave characteristic is obtained. The defect analysis of acoustic wave transmission method in experimental simulation is realized, and the validity of acoustic detection method is verified by experiments. The shortcoming of ultrasonic wave measurement is that ultrasonic wave is judged only by sound velocity and amplitude. Provides the basis for the method of judging the measured waveforms in engineering. 3. Based on the experiment and theory of acoustic wave transmission method, the project quality of a project across the sea in Liaoning Province is evaluated. The acoustic discriminant method is used to analyze the factors such as wave velocity, amplitude and so on, and the qualitative and quantitative analysis is carried out on the inside of the pile foundation. The influence of the defects in the pile on the quality and safety of the pile can be judged.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.16

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