發(fā)布時間：2018-12-10 14:55

【摘要】：探地雷達(dá)作為一個快速、高效、無破損的探測工具，已經(jīng)廣泛應(yīng)用于道路工程無損檢測中。通過對實測探地雷達(dá)信號進(jìn)行反演分析，可以對路面結(jié)構(gòu)層厚度、介電參數(shù)、含水量以及是否存在脫空等結(jié)構(gòu)病害做出判斷。進(jìn)行反演分析的關(guān)鍵就是構(gòu)建探地雷達(dá)電磁波在層狀有耗介質(zhì)中傳播的正演模型和尋找高效的反演優(yōu)化算法。本文針對目前探地雷達(dá)正反演算法中存在的一些問題，提出了基于傳輸線算法的正演模型以及基于1D-TLM剝層反演的反演策略，該方法對探地雷達(dá)基礎(chǔ)理論與應(yīng)用技術(shù)的發(fā)展具有一定推動作用。取得的主要成果和結(jié)論如下： （1）基于TLM方法建立了探地雷達(dá)電磁波在層狀有耗介質(zhì)中的傳播模型。將FDTD算法中的PML邊界條件引入到TLM方法中，依據(jù)該模型模擬合成了層狀結(jié)構(gòu)體中探地雷達(dá)的反射信號，通過與FDTD算法模擬結(jié)果進(jìn)行對比，驗證了算法模型的有效性和精確性。 （2）從反演問題的本質(zhì)出發(fā)，將1D-TLM模型方法與剝層法相結(jié)合，建立了基于1D-TLM的模型參數(shù)調(diào)整算法。 （3）運(yùn)用譜估計技術(shù)對仿真信號和探地雷達(dá)實際信號進(jìn)行了處理，仿真和實驗結(jié)果表明MUSIC方法得到的信號功率譜曲線可以準(zhǔn)確的估計出信號中所含正弦波的個數(shù)及其頻率，MUSIC與最小二乘法的結(jié)合算法能夠估計出各信號的幅值分量和相位參數(shù)，達(dá)到對實際信號進(jìn)行噪聲處理的目的。 （4）將雷達(dá)信號預(yù)處理技術(shù)與基于TLM的正反演算法結(jié)合起來成功用于實際層狀路面結(jié)構(gòu)分析，實驗結(jié)果表明本文算法可以用于實際層狀結(jié)構(gòu)處理，得到反演結(jié)果誤差控制在了8%內(nèi)，能夠滿足工程精度需要；利用探地雷達(dá)方法討論了標(biāo)準(zhǔn)砂含水量與介電常數(shù)的關(guān)系，根據(jù)實際實驗數(shù)據(jù)重新擬合了Topp公式和Alharathi公式，進(jìn)一步驗證了探地雷達(dá)方法檢測層狀結(jié)構(gòu)層含水量的實用性。
[Abstract]:Ground penetrating radar (GPR), as a fast, efficient and nondestructive detection tool, has been widely used in road engineering nondestructive testing. Based on the inversion analysis of the measured ground penetrating radar signal, the structural diseases such as the thickness of pavement structure layer, dielectric parameters, water content and the existence of voids can be judged. The key of inversion analysis is to construct the forward model of ground penetrating radar electromagnetic wave propagation in layered lossy medium and to find an efficient inversion optimization algorithm. In this paper, aiming at some problems existing in GPR forward and inverse algorithms, the forward modeling based on transmission line algorithm and the inversion strategy based on 1D-TLM stripping inversion are proposed. This method can promote the development of the basic theory and application technology of GPR. The main results and conclusions are as follows: (1) based on TLM method, the propagation model of GPR electromagnetic wave in layered lossy media is established. The PML boundary condition in the FDTD algorithm is introduced into the TLM method, and the reflected signals of the ground penetrating radar in the layered structure are simulated and synthesized according to the model. The validity and accuracy of the model are verified by comparing the results with the simulation results of the FDTD algorithm. (2) starting from the essence of the inversion problem, a model parameter adjustment algorithm based on 1D-TLM is established by combining the 1D-TLM model method with the delamination method. (3) the simulated signal and the actual signal of ground penetrating radar are processed by using spectrum estimation technique. The simulation and experimental results show that the power spectrum curve obtained by MUSIC method can accurately estimate the number and frequency of sinusoidal wave contained in the signal. The combination of MUSIC and least square algorithm can estimate the amplitude components and phase parameters of each signal, and achieve the purpose of noise processing of the actual signal. (4) the radar signal preprocessing technology and the forward and inverse algorithm based on TLM are successfully applied to the analysis of the actual layered pavement structure. The experimental results show that the proposed algorithm can be used in the practical layered structure processing. The error of inversion results is controlled within 8%, which can meet the need of engineering precision. The relationship between the moisture content of standard sand and the dielectric constant is discussed by using the GPR method. The Topp formula and the Alharathi formula are refitted according to the actual experimental data, and the practicability of the GPR method in detecting the moisture content of the layered structure is further verified.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：P631.3;U412.22

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 魏超;李小凡;鄭曉東;;基于群體搜索的串行蒙特卡羅反演方法的并行算法(英文)[J];Applied Geophysics;2010年02期

2 劉四新;曾昭發(fā);徐波;;三維頻散介質(zhì)中地質(zhì)雷達(dá)信號的FDTD數(shù)值模擬[J];吉林大學(xué)學(xué)報(地球科學(xué)版);2006年01期

3 仝傳雪;劉四新;王春輝;;時域有限差分法(FDTD)模擬探地雷達(dá)極化測量[J];吉林大學(xué)學(xué)報(地球科學(xué)版);2006年S1期

4 周輝林;田茂;熊俊志;;探地雷達(dá)回波信號的特征提取和分類[J];電波科學(xué)學(xué)報;2006年04期

5 王波;吳振森;趙振維;王紅光;;基于蟻群算法的雷達(dá)海雜波反演蒸發(fā)波導(dǎo)研究[J];電波科學(xué)學(xué)報;2009年04期

6 鄧世坤;克�；舴蚍e分偏移法在探地雷達(dá)圖象處理中的應(yīng)用[J];地球科學(xué);1993年03期

7 馮德山;戴前偉;;高速公路路面厚度探地雷達(dá)檢測[J];地球物理學(xué)進(jìn)展;2008年01期

8 鄧世坤,王惠濂;探地雷達(dá)圖像的正演合成與偏移處理[J];地球物理學(xué)報;1993年04期

9 張云華，陳抗生;傳輸線矩陣方法的研究及其應(yīng)用進(jìn)展[J];電子學(xué)報;1995年06期

10 吳小利;;祁連山北緣斷裂滑動參數(shù)的GPS數(shù)據(jù)蟻群算法反演研究[J];工程地球物理學(xué)報;2011年02期

，

本文編號：2370778