地质雷达超前预报正演模拟及应用  

Forward Modeling and Application of GPR Forward Prediction

作　　者：郑立斐 肖立拓 李小青[1] ZHEN Lifei;XIAO Lituo;LI Xiaoqing(School of Civil Engineering and Mechanics,Huazhong University of Science and Technology,Wuhan 430074,China;Guangzhou Municipal Engineering Design and Research Institute,Guangzhou 510000,China)

机构地区：[1]华中科技大学土木工程与力学学院,武汉430074 [2]广州市市政工程设计研究总院,广州510000

出　　处：《交通科技》2018年第2期76-81,共6页Transportation Science & Technology

摘　　要：地质雷达超前预报往往受环境、操作、数据处理和图像解释等因素影响,使得预报结果有一定的误差。文中针对各向同性均匀介质和典型不良地质情况进行建模,利用时域有限差分法对地质雷达探测进行正演模拟,通过分析雷达剖面图、时域波形图和频谱图,总结出典型不良地质体的地质雷达解释准则,电导率越大,波的振幅吸收越明显;相邻界面相对介电常数的差值越大,反射波振幅越大;在非色散介质中,雷达信号具有较好的保真性能,色散介质对信号吸收更强,保真性较差。并结合工程实例验证了地质雷达探测正演模拟和解释准则的可靠性。The advanced geological forecast of GPR is often influenced by factors such as environment,operation,data processing and image interpretation,and there is a certain error in the forecast result.In this paper,the modeling of isotropic homogeneous medium and typical bad geological conditions is performed,and the forward modeling of GPR detection is made by using time domain finite difference method.Through the analysis of radar profile,time domain waveform diagram and spectrum diagram,the geological radar interpretation criteria for typical bad geological bodies are summed up.It is concluded that the greater the conductivity,the more obvious the absorption of the wave amplitudeis.The greater the difference between the relative dielectric constant of the adjacent interface,the greater the amplitude of the reflected wave is.In the non-dispersive medium,the radar signal has good fidelity,the dispersive medium is stronger for the signal absorption and the fidelity is poor.Combined with the engineering example,the reliability of the forward modeling and interpretation criteria for GPR detectionare verified.

关 键 词：超前地质预报 地质雷达 正演模拟 

分 类 号：U452.11[建筑科学—桥梁与隧道工程]