高聚物注浆材料介电特性及其探地雷达无损检测方法研究

A expandable and no-water reacted polymer grouting material has been widely used in the repair and reinforcement of roads and other infrastructure projects. The selection of the electromagnetic wave velocity in polymer grouting material is the key for the detection accuracy of polymer grouting distribution using Ground Penetrating Radar (GPR). Firstly, in this study, the permittivity property of the polymer material is studied through laboratory experiment. The effect of the density, temperature, detection frequency on dielectric constant of the polymer material and the impact of high expansion of the polymer material on the dielectric property of the surrounding medium are analized. It can provide basis for appropriate selection of wave speed in detection process. Secondly, through 1:1 field model detectiong test, the measured profiles of typical pavement disease model, such as crack and void, are obtained by GPR before and after grouting at different detection frequencies. On this basis, the three dimensional numerical simulation research on the distribution of polymer grouting is developed by Symplectic Euler method, and the imaging rules of different grouting forms on the GPR profiles are summarized. This project aims to reveal the variation of the polymer material dielectric property and the propagation of electromagnetic waves in the pavement structure filled with polymer materials through laboratory bioassay, field test and numerical simulation. It can provide the theoretical foundation and scientific basis for evaluation of polymer grouting effect.

具有膨胀性的非水反应类高聚物注浆材料已广泛应用于道路等基础设施的修复和加固处理。采用探地雷达检测高聚物浆液分布时，介质中电磁波速的确定是保证探测精度的关键之一。本项目拟首先通过室内试验，研究高聚物材料随密度、温度、频率变化规律及材料高膨胀性对于周围介质介电特性的影响，并基于现场金属板模型探测试验所获实测雷达波形，反算材料介电常数，验证室内试验结果，为检测时选取合理的波速提供依据；其次，通过1:1模型探测试验，得到不同检测频率下裂缝、脱空等典型道路病害注浆前后的实测剖面图。在此基础上，基于辛Euler算法对高聚物浆液分布形态进行三维数值模拟研究，总结不同浆液形态在探地雷达时程剖面图上的成像规则。本项目旨在通过室内测定、现场试验与数值模拟相结合的手段，揭示高聚物材料介电特性变化规律及电磁波在充填高聚物材料路面结构中的传播规律，为采用探地雷达准确评价高聚物注浆效果提供理论基础和科学依据。

具有自膨胀性的非水反应类高聚物注浆材料已广泛应用于交通、水利、市政等基础设施的修复和加固处理中，但高聚物注浆效果评价技术的理论与试验研究发展十分缓慢。目前仍缺乏准确、高效的注浆效果检测评价手段，无法对高聚物浆液的分布以及连续性做出快速准确的判断。本项目通过室内测定、现场试验与数值模拟相结合的手段，对高聚物材料介电特性变化规律及电磁波在充填高聚物材料路面结构中的传播规律等问题进行了深入研究。主要结果如下：（1）研制了高聚物注浆材料试件成型磨具，制作了不同密度高聚物试件，采用“网络分析仪”，基于同轴探头法，研究了高聚物注浆材料介电常数、电导率随材料密度、温度以及频率变化规律；（2）基于辛Euler算法，构建了探地雷达电磁波在三维有耗介质中传播的数值模型，推导了适用于辛算法的吸收边界条件和激励源施加方式，模拟了不同病害类型、不同病害位置、不同病害形状对于剖面图的影响，总结了注浆前后剖面图变化规律；（3）在试验场1:1水泥混凝土路面模型上制作脱空、不密实等典型道路病害，获取不同病害注浆前后探地雷达回波信号，总结了典型道路病害注浆前后探地雷达剖面图变化规律。研究成果为采用探地雷达准确评价高聚物注浆效果提供了理论基础和科学依据，已在河南省三浙高速公路、山西省侯平高速公路等高速公路高聚物注浆维修工程中得到应用，具有显著经济和社会效益。