电磁波CT技术探测溶洞的模拟分析与应用研究

doi:10.16285/j.rsm.2017.2292

›› 2018, Vol. 39 ›› Issue (S1): 544-550.doi: 10.16285/j.rsm.2017.2292

• 测试技术 • 上一篇

电磁波CT技术探测溶洞的模拟分析与应用研究

黄生根¹，刘东军²，胡永健¹

1.中国地质大学（武汉）工程学院，湖北武汉 430074；2. 中交集团第二航务工程局有限公司技术中心，湖北武汉 430040

收稿日期:2017-11-17 出版日期:2018-07-20 发布日期:2018-09-02
作者简介:黄生根，男，1967年生，博士，教授，主要从事岩土工程教学与研究。

Simulation analysis and application study of electromagnetic wave computed tomography in detecting karst caves

HUANG Sheng-gen¹, LIU Dong-jun², HU Yong-jian¹

1. Faculty of Engineering，China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China; 2. National Enterprise Technology Center, China Communications Construction Company Second Harbour Engineering Co., Ltd., Wuhan, Hubei 430040, China

Received:2017-11-17 Online:2018-07-20 Published:2018-09-02

摘要/Abstract

摘要： 目前应用电磁波CT技术进行溶洞探测时对于溶洞形态和填充状态的解释与判断尚缺乏成熟的理论依据。在FDTD(时域有限差分法）基础上，采用Matlab软件编程建立CT技术探测溶洞模型，在模型边界处特意设置PML完全匹配层和PEC完善导体。模拟分析和实验探测结果表明，（1）电磁波穿过溶洞时在溶洞边界处发生折射现象，溶洞内部发生反射、绕射和障碍增益现象，且电磁波能量的衰减主要由折射现象产生；（2）当溶洞内充填物有水存在时，因反射现象使一部分电磁波滞留在溶洞内部，该部分电磁波在溶洞内部不断发生反复的反射和绕射现象；（3）经过溶洞后电磁波波形的扰动主要由反射现象及滞留在溶洞内部电磁波造成；（4）当溶洞对电磁波吸收系数发生改变时需综合考虑填充物种类及地层含水率等因素的影响。最后应用模拟结果对实际工程试验层析成像数据进行了判断和解释，将所得判定结果与勘察资料进行对比，二者基本吻合。验证了模拟结果的准确性和应用电磁波CT技术探测溶洞的可行性，可为今后层析成像的结果解释和判断提供借鉴和理论依据。

关键词: 溶洞, 电磁波CT, FDTD算法(时域有限差分法), 吸收系数

Abstract: There is still a theoretical defect in interpretation and judgment of karst morphology and filling state in karst cave detection using electromagnetic wave computed tomography. In order to solve practical problems in the detection, on the basis of finite-different time-domain(FDTD) algorithm, a numerical CT detection model is established using Matlab. A perfectly matched layer(PML) and a perfect electric conductor(PEC) are set at the boundary of computation model to prevent electromagnetic wave getting into the model again after it passed through the boundary. Simulation and experiment results show that: (1) When the electromagnetic wave passes through karst cave, it refracts at the cave boundary. And within the cave, the phenomenon of reflection, diffraction, and obstacle gain occur. Energy attenuation of electromagnetic wave is mainly caused by refraction. (2) When the cave filled with water, the reflection makes a part of the electromagnetic wave remains in the cave inside, this part of wave reflects and diffracts repeatedly inside the cave. (3) After electromagnetic wave passing through the cave, the disturbance of the waveform is mainly caused by the reflection phenomenon and the electromagnetic wave trapped inside the cave. (4) We have to consider the influence of the filling type, water content and other factors when the electromagnetic wave absorption coefficient changes in karst caves. At last，the tomography data obtained in practical detection are judged and interpreted according to the simulation results. By comparing the interpretation of tomography with previous investigation data, the accuracy of the simulation results and the reliability of the application of electromagnetic wave CT technology in detecting karst caves are validated. This research provides a reference and a theoretical basis for interpreting and judging tomography results in the future.

Key words: karst cave, electromagnetic wave computed tomography, FDTD(finite-different time-domain) algorithm, absorption coefficient

中图分类号:

TP206+.1

黄生根，刘东军，胡永健，. 电磁波CT技术探测溶洞的模拟分析与应用研究[J]. , 2018, 39(S1): 544-550.

HUANG Sheng-gen, LIU Dong-jun, HU Yong-jian，. Simulation analysis and application study of electromagnetic wave computed tomography in detecting karst caves[J]. , 2018, 39(S1): 544-550.

参考文献

相关文章 15

[1]	汪进超, 王川婴, 唐新建, 韩增强, 王益腾, 胡胜. 基于多频钻孔声呐的溶洞探测方法研究[J]. 岩土力学, 2020, 41(1): 353-361.
[2]	袁维, 刘尚各, 聂庆科, 王伟, . 基于冲切破坏模式的嵌岩桩桩端溶洞顶板临界厚度确定方法研究[J]. 岩土力学, 2019, 40(7): 2789-2798.
[3]	戴国亮，万志辉 ,竺明星，龚维明, . 基于黏度时变性的桩端压力浆液上返高度模型及工程应用[J]. , 2018, 39(8): 2941-2950.
[4]	赵明华，唐咸力，肖尧，杨超炜. 考虑厚跨比的基桩下伏溶洞顶板冲切特性试验研究[J]. , 2018, 39(4): 1159-1167.
[5]	赵明华，朱志仁，黄明华，杨超炜，徐卓君. 考虑基桩嵌岩段侧阻的岩溶区顶板安全厚度计算[J]. , 2018, 39(11): 4201-4209.
[6]	雷勇，尹君凡，陈秋南，杨威,. 基于极限分析法的溶洞顶板极限承载力研究[J]. , 2017, 38(7): 1926-1932.
[7]	张震，陈忠达，朱耀庭，胡文华，吴福泉，刘超群,. 地应力对路基下伏溶洞稳定性的影响[J]. , 2016, 37(S2): 715-723.
[8]	戴自航，范夏玲，卢才金,. 岩溶区高速公路路堤及溶洞顶板稳定性数值分析[J]. , 2014, 35(S1): 382-390.
[9]	周德泉，李传习，杨帆，付玉芬. 空隙岩体与溶洞充填混凝土竖向变形特性对比试验研究[J]. , 2011, 32(5): 1309-1314.
[10]	周雪铭，刘辉，彭川，吴羡. 岩溶隧道开挖对溶洞处治结构影响的数值模拟分析[J]. , 2011, 32(1): 269-275.
[11]	符策简. 岩溶地区隐伏溶洞顶板稳定性及变形分析[J]. , 2010, 31(S2): 288-291.
[12]	黎华清，徐远光，甘伏平，赵伟，卢建集. 孔间电磁波CT法在左江电站火成岩坝基风化结构评价中的应用[J]. , 2010, 31(S1): 430-434.
[13]	吴荣新，刘盛东，肖玉林，徐翀. 工作面无线电波透视实测场强成像分析及应用[J]. , 2010, 31(S1): 435-440.
[14]	黎华清，卢呈杰，韦吉益，劳武，. 孔间电磁波CT探测揭示水库坝基岩溶形态特征 ——以广西靖西大龙潭水库帷幕灌浆为例[J]. , 2008, 29(S1): 607-610.
[15]	宋战平，綦彦波，李宁,. 顶部既有隐伏溶洞对圆形隧道稳定性影响的数值分析[J]. , 2007, 28(S1): 485-489.

Metrics

Viewed

Full text

Abstract

Cited

Shared

Discussed

电磁波CT技术探测溶洞的模拟分析与应用研究

Simulation analysis and application study of electromagnetic wave computed tomography in detecting karst caves

PDF (Chinese)

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 15

Metrics

本文评价

推荐阅读 0