【作者】 谢国兰；

【导师】 周辉林； 徐剑萍；

【作者基本信息】 南昌大学 ， 电子与通信工程， 2009， 硕士

【摘要】 随着通车里程不断地增加,交通流量不断地增大,超重车辆绝对数量也不断地增加,加之施工不合理,使得大部分高速公路普遍发生了早期病害。其中对路面使用性能和使用寿命影响最大的是结构性破坏、水破坏和严重车辙,这严重影响了行车安全,并且进一步导致维修成本的增加。而高速公路浅层含水量可从一定程度上反映高速公路浅层质量状况。常用的无损地下含水量检测技术主要有红外反射法和时域反射法两种,但是它们存在检测速度慢、且不能连续大规模的对高速公路浅层含水量进行估计。而探地雷达具有快速测量,使用起来便捷,对所测物无损害无干扰,可重复测量,适合大面积测量等优点,近来广泛的用于高速公路基础设施检测。但是,GPR跟光学成像设备不同,它不能直接反映目标的特征。因此,使用GPR勘查高速公路路面浅层质量时,如何由获取的GPR数据估计高速公路路面浅层含水量成为问题的关键。本文的主要工作是结合探地雷达技术、信号检测与估计及信号处理技术实现高速公路浅层含水量的自动估计。其主要技术手段和研究内容为:1)高速公路浅层层界面检测及时延估计:主要利用探地雷达回波信号杂波抑制算法和阈值检波法实现探地雷达数据预处理和高速公路层界面检测和时延估计:2)高速公路浅层介电常数反演和含水量估计:利用每层层界面反射信号的幅度,通过经验模型反演每层介电常数和通过Topp和Roth经验模型反演高速公路浅层含水量。更多还原

【Abstract】 As the increase in traffic mileage and traffic flow, and the swelling in overloaded vehicles, and the improperness in construction, damages spread to most of highways in China. The most deadly factors that affect highway usability and working life are damages to highways’ structures, destructions to water and the overloading of vehicles. This severely influences security of driving and leads to increase in maintenance cost. To solve these problems, it is important to understand the situation of the highway shallow-layer’s quality. The water content of shallow-layer could reflect the situation to some extent.Infrared reflectance method and time domain reflectance method are two widely used safe methods to detect water content. But, both of those two methods are slow, and they cannot be used to detect shallow-layer water content in a wide range. While, not only as a quick method, the ground penetrating radar (GPR) method is also easy to use and has no damage to subjects to be detected. GPR is a repeatable measuring method. Most importantly, it can be used to measure water content of a large area. This method is now prevailed in detecting fundamental facilities on the highway. But, being different from optical imaging, GPR cannot reflect characters of subjects directly. Thus, when GPR is used in analyzing highway shallow-layer’s quality, how to get data to estimate water content in shallow-layer is the key issue.The main work of this study is to detect water content of highway shallow-layer automatically by combining GPR, signal detecting and analyzing technology and signal processing technology. The main content of the study are:1) Detection and delaying estimation of highway shallow-layer’ layer interface: calculating GPR reflecting wave signal by using clutter suppression algorithm and threshold detector method to pre-process GPR data, detect highway layer interface and estimate delay.2) Inversion of highway shallow layer’s dielectric constant and estimation of water content: applying amplitudes of each layer interfaces’ reflecting signals to calculate highway shallow layer’s water content by using experiential model to invert each layer’s dielectric constant and using Topp and Roth experiential model toinvert water content of highway shallow layer.更多还原