道路路基脱空病害雷达波场数值模拟与瞬时属性分析

针对道路路基脱空病害的快速识别，采用时间域有限差分法进行病害的雷达波长数值模拟，模拟了脱空病害不同大小、长度、位置及填充的差异，并通过图像增益和复信号分析技术提取雷达波场的振幅、相位和频率等瞬时属性特征，分析了不同脱空地质的雷达波场响应特征。研究结果表明：根据路基脱空病害的地质雷达瞬时振幅图像和单道波归一化幅值可推算出脱空病害上界面信息和脱空区域介质类型；根据充气脱空病害和充水脱空病害瞬时相位图像特征，可判断出路基结构层间信息和脱空病害区域和边界位置；根据充水脱空病害和充气脱空病害瞬时频率图像，可判断出高频和低频电磁波存在位置。此外，根据充水脱空病害单道波瞬时频率图，可得到正向电磁波存在位置，并作为脱空病害下界面位置判断依据。研究成果可为道路病害的智能识别和快速判识提供理论依据。

Numerical Simulation and Instantaneous Attribute Analysis of GPR Wave Field for Road Subgrade Void

For rapid identification of road subgrade void disease, the time domain finite difference method is used to simulate the radar wavelength of the disease, the difference of different size, length, location and filling of void disease were simulated. The instantaneous attribute characteristics such as amplitude, phase and frequency of radar wave field are extracted by image gain and complex signal analysis technology, and the radar wave field response characteristics of different void geology are analyzed. The results show that the information of the upper interface of the subgrade void disease can be calculated from the instantaneous amplitude image of the ground penetrating radar and the normalized amplitude of the single wave, and the medium type of the void area can be calculated； According to the instantaneous phase image characteristics of air filled and water filled void diseases, the information between layers of subgrade structure and the area and boundary position of void diseases can be judged; According to the instantaneous frequency images of the water filled void disease and the air filled void disease, the existence positions of the high-frequency and low-frequency electromagnetic waves can be judged, which can be used as the basis for judging the position information of the void area. In addition, according to the instantaneous frequency diagram of single wave of water filled void disease, the existence position of forward electromagnetic wave can be obtained, which can be used as the basis for judging the position of the lower interface of void disease. The research results can provide theoretical basis for intelligent recognition and rapid identification of road diseases.