采用地质雷达系统对混凝土裂隙进行成像扫描,对于监测和预防混凝土内部的裂隙具有重大的意义。针对传统后向投影算法存在一定的缺陷,易受杂波干扰,得到混凝土裂隙的成像分辨率和清晰度较差,提出了一种改进后向投影算法来获得高分辨率的混凝土裂隙成像,该方法主要是采用多次累积叠加的方法对成像点之间的互相响应性进行相关分析, 抑制了杂波的干扰,然后采用电磁波衰减补偿系数对所得结果进行补偿,从而提高了裂隙成像的分辨率。利用改进后向投影算法对地质雷达在地铁站的混凝土裂隙进行成像与检测,所得的结果与工程现场实测的裂隙一致,证明了改进后向投影算法在地质雷达混凝土裂隙成像中的有效性和实用性。

It is of great significance to monitor and prevent the cracks in concrete by using geological radar system to image and scan the cracks in concrete. However, because the traditional backward projection algorithm has some defects and is easy to be disturbed by clutter, the imaging resolution and clarity of the concrete cracks obtained are poor. Therefore, an improved back projection algorithm is proposed to obtain high-resolution imaging of concrete cracks. This method mainly uses the method of multiple cumulative superposition to analyze the mutual response between imaging points, so as to suppress the interference of clutter. Then,the electromagnetic wave attenuation compensation coefficient is used to compensate the obtained results, thereby improving the resolution of fracture imaging. The experiments show that improved back projection algorithm is used to image and detect the concrete cracks of the ground penetrating radar in the subway station, and the results are consistent with the actual cracks on the engineering application site, which prove the effectiveness and practicability of the improved back projection algorithm in ground penetrating radar concrete crack imaging.

TN959

河南省高等学校“专业综合改革试点”项目(豫教高(2015)33号)