基于相位角变化的桩基缺陷位置识别方法

传统的低应变反射波信号解读方法具有很大的经验性,因而对桩身的缺陷位置常常作出错误的估计。为合理判断桩身缺陷位置,提出一种新的基于相位角变化的桩基缺陷位置改进识别方法。首先,利用解析模态分解定理和递归希尔伯特变换提取了重点关注频带范围内的反射波纯调频信号;其次,对提取的纯调频信号进行小波变换并通过相位角的变化判别桩身缺陷位置;最后,通过王乾1号大桥桩基实测数据验证了所提出方法的有效性。研究结果表明,该方法能够有效判断桩身缺陷疑似位置,为后续的缺陷位置排查提供了便利,但仍需结合其他桩基损伤识别方法和相关工程资料进行验证。

Pile Defects Detection Based on the Change of Phase Angle

Since traditional low strain reflected wave method is essentially empirical, a misleading estimation of the damage location of pile foundations may be made. To address this issue, an improved method based on the change of phase angle is presented to detect the position where effects occur. Firstly, the analytical modal decomposition and recursive Hilbert transform are combined to extract the FM parts in a specific region of interest. Secondly, continues wavelet transform is performed on the extracted FM parts to acquire the phase angle and thus the damage is identified according to the varying of the phase angle. Finally, the measured data of the pile of Wangqian #1 Bridge is used to verify the effectiveness and accuracy of the proposed method, and the results demonstrate that the proposed method can preliminarily detect the damage location of the pile and thus facilitate the following damage confirmation, but it still needs more extra proofs based on other damage detection methods or engineering data.