The Journal of Engineering Geology (지질공학)

The Korean Society of Engineering Geology (대한지질공학회)
권호 표지
DOI QR코드

DOI QR Code

Strategy for Improving the Resolution of Electrical-resistivity Inversions for Detecting Soft Ground at Shallow Depths (~ 10 m)

천부(약 10 m) 연약 지반 탐지를 위한 전기비저항 역산 해상도 향상 전략

  • Jang, Hangilro (Department of Energy and Mineral Resources Engineering, Sejong University, Archaeology Research Division, National Research Institute of Cultural Heritag) ;
  • Song, Seo Young (Department of Energy and Mineral Resources Engineering, Sejong University) ;
  • Kim, Bitnarae (Department of Energy and Mineral Resources Engineering, Sejong University) ;
  • Nam, Myung Jin (Department of Energy and Mineral Resources Engineering, Sejong University)
  • 장한길로 (세종대학교 에너지자원공학과, 국립문화재연구소 고고연구실) ;
  • 송서영 (세종대학교 에너지자원공학과) ;
  • 김빛나래 (세종대학교 에너지자원공학과) ;
  • 남명진 (세종대학교 에너지자원공학과)
  • Received : 2018.01.16
  • Accepted : 2018.07.15
  • Published : 2018.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study introduces a DC resistivity inversion method that incorporates structural and inequality constraints to enhance the resolution of resistivity inversions, and presents sample inversion results with these constraints. In the constrained inversions, a base model is constructed from a layered model through interpretation of other geophysical data. Inversion tests establish that both the structural and inequality constraints produce better resistivity models than the unconstrained inversion. However, the inequality inversion not only reproduces the exact layered structure of the background, it reproduces conductive anomalies at a depth of ~ 10 m when an inexact base model of electrical resistivity is used.

이 연구는 전기비저항 역산의 해상도를 높이기 위한 구조제약과 부등식 제약조건을 적용한 전기비저항역산법을 소개하고 적용한 결과를 보여준다. 이들 역산에서는 지하투과레이다와 표면파 탐사자료로부터 사전 해석된 층서구조를 전기비저항 참조모델로 도입하고 구조제약과 부등식 제약의 유용성을 합성모델을 이용한 역산실험으로 확인하였다. 연약지반 조건을 가정한 실험모델에 대한 구조제약과 부등식 제약 역산실험 모두 일반적인 전기비저항 역산보다 향상된 역산결과를 보여주었으나, 부등식제약 역산에서는 참조모델이 다소 부정확한 경우에도 배경층서구조를 정확히 재구성하는 동시에 천부(약 10 m 심도)의 전도성 이상체들도 정확히 나타내는 역산결과를 보여주었다.

Keywords

References

  1. Archie, G.E., 1942, The electrical resistivity log as an aid in determining some reservoir characteristics, Transactions of the AIME, 146(1), 54-62. https://doi.org/10.2118/942054-G
  2. Cassidy, N.J., 2009, Electrical and magnetic properties of rocks, soils, and fluids, In: Ground Penetrating Radar Theory and Applications, Jol, H. M., pp. 41-72, Elsevier.
  3. Cha, J., Lee, J., Kim, W., 2017, Development of 3-D flow model for porous media with scenario-based ground excavation, Journal of Korean Society of Disaster & Security, 10(1), 19-27. https://doi.org/10.21729/ksds.2017.10.1.19
  4. Commer, M., Newman, G.A., 2008, New advances in three-dimensional controlled-source electromagnetic inversion, Geophysical Journal International, 172(2), 513-535. https://doi.org/10.1111/j.1365-246X.2007.03663.x
  5. Gassmann, F., 1951, Elastic waves through a packing of spheres, Geophysics, 16(4), 673-685. https://doi.org/10.1190/1.1437718
  6. Han, N., Nam, M.J., Kim, H.J., Lee, T.J., Song, Y., Suh, J.H., 2008, Efficient three-dimensional inversion of magnetotelluric data using approximate sensitivities, Geophysical Journal International, 175(2), 477-485. https://doi.org/10.1111/j.1365-246X.2008.03894.x
  7. Han, Y.S., 2017, Complex detect system for the underground cavern and object detect, Journal of the Korean Geosynthetics Society, 16(4), 6-12.
  8. Hong, J., Ji, Y., Oh, S., Choi, S., 2015, A geophysical survey of subsidence area around limestone mine sites, Geophysics and Geophysical Exploration, 18(4), 207-215. https://doi.org/10.7582/GGE.2015.18.4.207
  9. Jang, H., Park, S., Kim, H.J., 2014, A simple inversion of induced-polarization data collected in the Haenam area of Korea, Journal of Geophysics and Engineering, 11(1), 015011 (6pp). https://doi.org/10.1088/1742-2132/11/1/015011
  10. Jang, H., Kim, H.J., Nam, M.J., 2016, Three-dimensional finite-difference time-domain modeling of ground-penetrating radar survey for detection of underground cavity, Geophysics and Geophysical Exploration, 19(1), 20-28. https://doi.org/10.7582/GGE.2016.19.1.020
  11. Kim J., Yi, M., Hwang, S., Song, Y., Cho, S., Synn, J., 2007, Integrated geophysical surveys for the safety evaluation of a ground subsidence zone in a small city, Journal of Geophysics and Engineering, 4(3), 332-347. https://doi.org/10.1088/1742-2132/4/3/S12
  12. Kim, H.J., Kim, Y., 2011, A unified transformation function for lower and upper bounding constraints on model parameters in electrical and electromagnetic inversion, Journal of Geophysics and Engineering, 8(1), 21-26. https://doi.org/10.1088/1742-2132/8/1/004
  13. Li, Y., Oldenburg, D.W., 2000, Incorporating geological dip information into geophysical inversions, Geophysics, 65(1), 148-157. https://doi.org/10.1190/1.1444705
  14. Park, C., Chun, S., Ku, B., Nam, M.J., 2014, A review and analysis on constructing electrical resistivity models for hydrocarbon reservoirs based on the characteristics of shale distribution, Journal of the Korean Society of Mineral and Energy Resources Engineers, 51(1), 97-115. https://doi.org/10.12972/ksmer.2014.51.1.97
  15. Park, S., Kim, C., Son, J., Kim, J., Yi, M., Cho, S., 2006, Detection of limesilicate cavities by 3-D electrical resistivity survey, Economic and Environmental Geology, 39(5), 597-605.
  16. Park, C.B., 2011, Imaging dispersion of MASW data - full vs. selective offset scheme, Journal of Environmental and Engineering Geophysics, 16(1), 13-23. https://doi.org/10.2113/JEEG16.1.13
  17. Park, C., Nam, M.J., 2014, A review on constructing seismic rock physics models based on Gassmann's equation for reservoir fluid substitution, Journal of the Korean Society of Mineral and Energy Resources Engineers, 51(3), 448-467. https://doi.org/10.12972/ksmer.2014.51.3.448
  18. Poluha, B., Porsani, J.L., Almeida, E.R., dos Santos, V.R.N., Allen, S.J., 2017, Depth estimates of buried utility systems using the GPR Method: Studies at the IAG/USP geophysics test site, International Journal of Geosciences, 8, 726-742. https://doi.org/10.4236/ijg.2017.85040
  19. Phung, K.T.N., Nam, M.J., Jung, S., 2014, A preliminary study on sensitivity of seismic responses to changes in reservoir parameters using various RPM-constructing strategies, Geosystem Engineering, 17(4), 207-218. https://doi.org/10.1080/12269328.2014.951775
  20. Reynolds, J., 2011, An introduction to applied and environmental geophysics, USA, Wiley.
  21. Sasaki, Y., 1994, 3-D resistivity inversion using the finite‐element method, Geophysics, 59(12), 1839-1848. https://doi.org/10.1190/1.1443571
  22. Sasaki, Y., 2004, Three-dimensional inversion of static-shifted magnetotelluric data, Earth, Planets and Space, 56(2), 239-248. https://doi.org/10.1186/BF03353406
  23. Saunders, J.H., Herwanger, J.V., Pain, C.C., Worthington, M.H., De Oliveira, C.R.E., 2005, Constrained resistivity inversion using seismic data, Geophysical Journal International, 160(3), 785-796. https://doi.org/10.1111/j.1365-246X.2005.02566.x
  24. Song, S., Lee, K., Yong, H., Kim, J., 2004, Electrical resistivity survey at the ground with micro-subsidence by excessive pumping of groundwater, Geophysics and Geophysical Exploration, 7(3), 197-206.
  25. Sun, J., Li, Y., 2015, Multidomain petrophysically constrained inversion and geology differentiation using guided fuzzy c-means clustering, Geophysics, 80(4), ID1-ID18. https://doi.org/10.1190/geo2014-0049.1
  26. Yi, M., Kim, J., Cho, S., Chung, S., Song, Y., 1999, Three-dimensional inversion of resistivity data, Geophysics and Geophysical Exploration, 2(4), 191-201.