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Study of Continuous Monitoring for Underground and Geotechnical Structures using Accelerometers

가속도계를 활용한 지하 및 지반구조물 상시 계측 방안에 관한 연구

  • Gunwoong Kim (Korea Institute of Civil Engineering and Building Technology, KICT)
  • 김건웅
  • Received : 2024.04.05
  • Accepted : 2024.05.03
  • Published : 2024.06.30

Abstract

Geotechnical structures such as dams, tunnels, and slopes require regular inspection and monitoring to ensure stability. Domestically, drones and accelerometers have become common tools for inspecting and monitoring various structures. However, drones have difficulty identifying internal changes in structures and the subsurface, and accelerometers generally serve for seismic design or strain measurement purposes. Therefore, this paper proposes to utilize accelerometers to monitor the internal information of the ground on a real-time or periodic basis. The proposed method utilizes a part of the analysis technique from the SASW test to monitor the stability and state changes of geotechnical structures. Cases where SASW was used to evaluate the safety of geotechnical structures, such as slopes, dams, and tunnels, were reviewed to verify the suitability of the technology. To make the proposed method more practical, the study considered using only the first-step analysis to derive the dispersion curve rather than the second-step analysis to determine the shear wave velocity profile, which requires complex analysis. The proposed technique is expected to enable the continuous monitoring and inspection of geotechnical structures by utilizing accelerometers.

댐과 터널 그리고 사면 같은 지반구조물의 정기적인 계측 및 모니터링은 안전성 유지를 위해 필요하다. 국내에서는 드론과 가속도계와 같은 장비를 활용하여 지반구조물에 대한 점검 및 모니터링을 수행한다. 하지만, 드론은 구조물 및 지반 내부의 변화를 파악에 어려움이 있고, 가속도계는 일반적으로 내진 설계나 변형량 측정에만 활용되고 있다. 이에 본 논문은 가속도계를 활용하여 지반 내부 정보를 실시간 또는 정기적으로 계측하기 위해 SASW 시험 활용을 제안하였다. 제안된 방법은 SASW 시험의 해석 기법의 일부분만 활용하여 지반구조물의 강도 및 상태 변화를 추적한다. 이를 위해, SASW를 활용하여 사면, 댐 및 터널과 같은 지반구조물의 안전성을 평가한 사례들을 분석하여 기술의 적합성을 확인하였다. 또한, 현장 적용성을 높이기 위해, 복잡한 해석을 요구하는 전단 속도 프로파일을 도출하는 2차 해석보다는 분산곡선을 도출하는 1차 해석만을 활용하는 방안을 모색하였다. 본 연구에서 제안된 기술을 통해 가속도계를 활용하여 지반구조물의 지속적인 모니터링 및 유지보수가 가능할 것으로 기대된다.

Keywords

References

  1. Haegeman, W. and Van Impe, W. F. (1999), "Characterization of Disposal Sites from Surface Wave Measurements", Journal of Environmental Engineering and Geophysics, Vol.4, No.27.
  2. Hwang, S. C. (2011), "Evaluation of the Application and Analysis Method at Seismic Design of Dam", Journal of the Korea Academia-Industrial Cooperation Society.
  3. Joh, S. H. (1996), Advances in the data interpretation technique for Spectral-Analysis-of-Surface-Waves (SASW) measurements, Doctoral dissertation, The University of Texas at Austin).
  4. Kausel, E. and Roesset, J. M. (1981), "Stiffness matrices for layered soils", Bulletin of the Seismological Society of America, Vol.71, pp.1743-1761.
  5. Kim, D. S., Shin, M. K. and Park, H. C. (2001), "Evaluation of density in layer compaction using SASW method", Soil Dynamics and Earthquake Engineering, Vol.21, pp.39-46.
  6. Kim, G. (2023), "Evaluation of Ground Compaction Using SASW Testing", Journal of the Korean Geosynthetics Society, Vol.22, No.4, pp.9-15.
  7. Kim, G., Hwang, S. and Stokoe, II K. H. (2022), "Evaluation of the Lateral Variability in the Vs Profiles at Geotechnical Sites using the Spectral-Analysis-of-Surface-Waves (SASW) Method", 12th National Conference on Earthquake Engineering, No.10181.
  8. Lee, H. C., Kwon, K., Moon, C. and Jo, Y. (2018), "Survey Equipment Development of Stability Evaluation for Rock Slope using Drone", Journal of the Korea Institute for Structural Maintenance and Inspection, Vol.22, No.4, pp.91-99.
  9. Lee, Y., Kim, H. S., Ju, Y. T., Kim, D., Park, H. J. and Park, D. (2021), "Dynamic Factor of Safety Calculation of Slope by Nonlinear Response History Analysis", Journal of the Korean Geotechnical Society, Vol.37, No.9, pp.5-12.
  10. Nazarian, S. and Stokoe, K. H. (1984), "In situ shear wave velocities from spectral analysis of surface waves", 8th World Conference on Earthquake Engineering, Vol.3, pp.31-38.
  11. Park, D., Yu, J. I. and You, H. (2023), "A Research on Applicability of Drone Photogrammetry for Dam Safety Inspection", Journal of the Korea Institute for Structural Maintenance and Inspection, Vol.27, No.5, pp.30-39.
  12. Rix, G. J., Lai, C. G., Foti, S. and Zywicki, D. (1998), "Surface Wave Tests in Landfills and Embankments", ASCE Geotechnical Special Publication, Vol.75.
  13. Stokoe, K. H. and Nazarian, S. (1985), Measurement and use of shear wave velocity for evaluating dynamic soil properties, In R. D. Woods (Ed.), Use of Rayleigh waves in liquefaction Studies (pp. 187-196). ASCE.
  14. Stokoe, K. H., Cox, B., Clayton, P. and Menq, F. (2017a), "NHERI@UTEXAS Experimental Facility: Large-scale Mobile Shakers for Natural-hazards Field Studies", 16th World Conference on Earthquake Engineering, No.2387.
  15. Stokoe, K. H., Hwang, S. and Joh, S. H. (2017b), "Spectral-Analysis-of-Surface-Waves (SASW) testing to evaluate Vs profiles at geotechnical and geological sites", 16th World Conference on Earthquake Engineering, Santiago, No.4948.
  16. Stokoe, K. H., Hwang, S., Cox, B. R., Menq, F. Y., Roberts, J. N. and Park, K. (2019), "Field studies of the natural and built environments using large mobile shakers", Proceedings of the 7th International Conference on Earthquake Geotechnical Engineering, pp.1-10.
  17. Stokoe, K. H., Wright, S. G., Bay, J. A. and Roesset, J. M. (1994), Characterization of Geotechnical Sites by the SASW Method, In R. D. Woods (Ed.), Geophysical Characterization of Sites. Oxford Publishers.
  18. Yoon, G. H., Kim, S. K., Kang, Y. H. and Kang, M. J. (2021), "A study on the establishment of a smart dam safety management system", Korean Society of Civil Engineers Annual Conference, KSCE 2021 CONVENTION.