Abstract

In this study, the contact quality of shotcrete-rock structures is studied using the impact-echo method (IE) to detect defects in shotcrete with a thickness of 10 and 20 cm. Numerical and experimental studies were conducted. Traditional frequency-domain analysis can only provide a qualitative judgment, but it fails to quantitatively estimate the severity of defect on the contact surface. Wavelet packet decomposition is used to analyze the signal to obtain the distribution of energy in each frequency band. The relative energy eigenvalues of the wavelet packet were calculated later, and the energy characteristic index of shotcrete with different thicknesses and bonding conditions was obtained. An interface quality evaluation approach based on energy was provided to quantitatively evaluate the contact quality at the interface of the shotcrete-rock structures.

中文翻译：

---

冲击回波法分析喷石结构的小波包

摘要

在这项研究中，采用冲击回波法（IE）研究喷射混凝土与岩石结构的接触质量，以检测厚度为10和20 cm的喷射混凝土中的缺陷。进行了数值和实验研究。传统的频域分析只能提供定性判断，但不能定量估计接触表面缺陷的严重程度。小波包分解用于分析信号以获得每个频带中的能量分布。随后计算小波包的相对能量特征值，得到不同厚度和粘结条件的喷射混凝土的能量特征指标。