In view of the electrical characteristics of the media of different potential geological defects in embankment, corresponding geophysical models are built using the finite difference time domain (FDTD) algorithm with the perfectly matched layer absorbing boundary conditions (PML). GprMax software together with MatLab self-programming is employed for the GPR forward simulation. Result reveals that the amplitude and form of GPR reflected wave of hidden defects vary with shape, location, and electrical parameters. Forward simulation result accurately reflects the depth and horizontal position of hidden defects. Two engineering examples demonstrate that the results of GPR forward simulation are basically consistent with engineering verification, which proves that GPR can effectively detect the hidden dangers of embankment. The GPR forward simulation method is feasible, and is helpful to guide the further interpretation work more precisely.
Key words
detection of hidden dangers in embankments /
ground penetrating radar (GPR) /
hidden defective body /
finite difference time domain(FDTD) algorithm /
geophysical model /
wave field characteristics /
forward modeling
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References
[1] 全国历年堤防长度、保护耕地、保护人口和达标长度(数据篇)[J].中国防讯抗旱,2009(增刊1):183.
[2] 全国历年已建成水库数量、库容和有效灌溉面积(数据篇)[J].中国防讯抗旱,2009(增刊1):180.
[3] 柬庆鹏,冯 琳. 堤防隐患探测技术应用初探[J].中国水利,2005(5):51-52.
[4] 冷元宝,朱文仲,何 剑,等.我国堤坝隐患及渗漏探测技术现状及展望[J].水利水电科技进展,2002(2):59-62.
[5] 李大心. 探地雷达方法与应用[M].北京:地质出版社,1994.
[6] YEE K S. Numerical Solution of Initial Boundary Value Problem Involving Maxwell's Equations in Isotropic Media[J]. IEEE Transactions on Antennas and Propagation,1966,14(3):302-307.
[7] BERENGER J P. Perfectly Matched Layer for the Absorption of Eletromagnetic Waves[J]. Journal of Computation Physics, 1994, 114(2): 185-200.
[8] 刘四新,曾昭发,徐 波. 地质雷达数值模拟中有损耗媒质吸收边界条件的实现[J].吉林大学学报(地球科学版),2005,35(3):378-381.
[9] 肖明顺,昌彦君,曹中林,等. 探地雷达数值模拟的吸收边界条件研究[J].工程地球物理学报,2008,5(3):315-320.
[10]JOL H M. 探地雷达理论与应用[M]. 雷太文,童孝忠,周 旸,等,译. 北京:电子工业出版社,2011.
[11]DROSSAERT F H, GIANNOPOULOS A. A Nonsplit Complex Frequency-shifted PML Based on Recursive integration for FDTD Modeling of Elastic Waves[J]. Geophysics, 2007, 72(2): 9-17.
[12]DROSSAERT F H,GIANNOPOULOS A.Complex Frequency Shifted Convolution PML for FDTD Modelling of Elastic Waves[J].Wave Motion,2007,44(7/8):593-604.
[13]KOMATITSCH D, MARTIN R. An Unsplit Convolutional Perfectly Matched Layer Improved at Grazing Incidence for the Seismic Wave Equation [J]. Geophysics, 2007, 72(5): 255-167.
[14]黄 超,董良国.可变网格与局部时间步长的高阶差分地震波数值模拟[J] .地球物理学报,2009,52(1):176-168.
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