Sensitive Damage Detection of Reinforced Concrete Bridge Slab by “Time-Variant Deconvolution” of SHF-Band Radar Signal
Sensitive Damage Detection of Reinforced Concrete Bridge Slab by “Time-Variant Deconvolution” of SHF-Band Radar Signal
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DOI：
10.1109/tgrs.2018.2866991
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发表时间：
2019-03
影响因子：
8.2
通讯作者：
Takahiro Yamaguchi;Tsukasa Mizutani;Minoru Tarumi;Di Su
中科院分区：
文献类型：
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作者：
Takahiro Yamaguchi;Tsukasa Mizutani;Minoru Tarumi;Di Su
在本文中，我们专注于地质雷达（GPR）的基础设施的健康监测，特别是对钢筋混凝土（RC）桥梁板的监测。由于对非接触、高速监测技术的需求，可以处理大量老化的基础设施，地质雷达是一种很有前途的工具。然而，由于雷达图像由许多反射波组成，它们通常很难解释。此外，当常规探地雷达超高频波段波长超过10 cm时，由于目标损伤、裂纹、偏析等厚度为毫米至厘米量级，系统的空间分辨率不够。为了解决这些问题，为了灵敏的损伤检测的目的，我们提出了一种新的算法，利用超高频（SHF）带系统的反卷积的基础上。首先，利用一维桥板模型反推反射系数的分布。由于混凝土在SHF波段是一种有耗介质，因此在反褶积中考虑了信号的衰减。本文称之为“时变反褶积”。在仿真验证的基础上，通过现场试验研究了算法和频带对损伤检测精度的影响。结果表明，虽然1毫米的水平裂缝没有检测到的实测波，当它充满水，它是检测到的时变反褶积。此外，1毫米的干裂纹只检测时变反褶积在SHF波段，这大大强调了裂纹的反射系数的峰值。
In this paper, we focus on ground-penetrating radar (GPR) for infrastructural health monitoring, especially for the monitoring of reinforced concrete (RC) bridge slab. Due to the demand of noncontact and high-speed monitoring technique which can handle vast amounts of aging infrastructures, GPR is a promising tool. However, because radar images consist of many reflected waves, they are usually difficult to interpret. Furthermore, the spatial resolution of system is not enough considering the thickness of target damages, cracks, and segregation are millimeter-to-centimeter order while the wavelength of ordinary GPR ultrahigh-frequency band is over 10 cm. To address these problems, for the purpose of sensitive damage detection, we propose a new algorithm based on deconvolution utilizing a super high-frequency (SHF) band system. First, a distribution of reflection coefficient is inversely estimated by 1-D bridge slab model. Because concrete is found to be a lossy medium at SHF band, we consider the attenuation of signal in deconvolution. The algorithm is called “time-variant deconvolution” in this paper. After the validation by simulation, the effects of the algorithm and frequency band on damage detection accuracy are evaluated by a field experiment. Though the results show a 1-mm horizontal crack is not detected by measured waves, when it is filled with water, it is detected by time-variant deconvolution. Moreover, the 1-mm dried crack is detected only by time-variant deconvolution at SHF band, which greatly emphasizes the peaks of the reflection coefficient of the crack.