한국구조물진단유지관리공학회 논문집 (Journal of the Korea institute for structural maintenance and inspection)

  • 제26권3호
  • /
  • Pages.11-20
  • /
  • 2022
  • /
  • 2234-6937(pISSN)
  • /
  • 2287-6979(eISSN)
한국구조물진단유지관리공학회 (Korea Institute for Structural Maintenance Inspection)
권호 표지
DOI QR코드

DOI QR Code

전단파 토모그래피를 활용한 철도 콘크리트 궤도 슬래브 층분리 결함 평가

Evaluation of Debonding Defects in Railway Concrete Slabs Using Shear Wave Tomography

  • 이진욱 (한국철도기술연구원, 첨단궤도토목본부) ;
  • 기성훈 (동아대학교, ICT융합해양스마트시티공학과) ;
  • 이강석 (한양대학교, 건축학부 및 스마트시티공학과)
  • 투고 : 2022.01.14
  • 심사 : 2022.05.17
  • 발행 : 2022.06.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

이 연구의 주요 목적은 고속철도 콘크리트 궤도 슬래브의 콘크리트 슬래브(track concrete layer, TCL)와 도상안정층(hydraulically stabilized based course, HSB) 사이 층분리를 평가하기 위한 비파괴검사법으로 전단파 토모그래피 기술의 활용가능성을 실험적으로 확인하는 것이다. 이를 위하여 다채널 전단파 측정 장치(MIRA)를 활용하여 실물 크기로 제작된 고속철도 콘크리트 궤도 슬래브 실험체 내부의 층분리 결함을 평가하였다. 실물실험체는 Rheda 2000 시스템에 따라 설계 및 시공되었으며, 노반 위에 HSB를 타설하고, 그 위에 TCL이 타설된 2층 슬래브 구조를 갖는다. 실물실험체는 일부구간의 HSB상부에 스티로폼으로 제작된 인공결함(가로 및 세로가 각각 400mm이고 두께가 각각 5mm, 15mm인 압출폴리스티렌폼(XPS)보드 2개)을 삽입하여, TCL과 HSB 사이에 층분리 결함이 생기도록 시공하였다. 시험체의 층분리 구간에서 얻은 콘크리트 단층이미지는 층분리에 따른 균열 및 HSB와 지반사이의 계면에서 반사되는 신호를 효과적으로 보여 주었다. 한편 초음파 토모그래피 이미지에서 TCL 콘크리트의 매입물(철근, 트러스, 인서트 등)에서 반사된 신호와 층분리 결함 신호를 구분하기 위한 노이즈 제거를 위한 이미지 처리방법을 적용하여 층분리 결함을 효과적으로 분리하였다. 토모그래피 이미지에서 추출된 층분리 결함의 크기정보와 공간정보를 통합하여 층분리 지도로 재구성하였으며, 층분리 결함의 위치 및 크기를 시각화하는데 효과적인 것을 확인하였다.

The main purpose of this study is to investigate the applicability of the shear wave tomography technology as a non-destructive testing method to evaluate the debonding between the track concrete layer (TCL) and the hydraulically stabilized based course (HSB) of concrete slab tracks for the Korea high-speed railway system. A commercially available multi-channel shear wave measurement device (MIRA) is used to evaluate debonding defects in full-scaled mock-up test specimen that was designed and constructed according to the Rheda 200 system. A part of the mock-up specimen includes two artificial debonding defects with a length and a width of 400mm and thicknesses of 5mm and 10mm, respectively. The tomography images obtained by a MIRA on the surface of the concrete specimens are effective for visualizing the debonding defects in concrete. In this study, a simple image processing method is proposed to suppress the noisy signals reflected from the embedded items (reinforcing steel, precast sleeper, insert, etc.) in TCL, which significantly improves the readability of debonding defects in shear wave tomography images. Results show that debonding maps constructed in this study are effective for visualizing the spatial distribution and the depths of the debondiing defects in the railway concrete slab specimen.

키워드

과제정보

이 논문은 2022년 해양수산부 재원으로 해양수산과학기술진흥원의 지원 (항만인프라 재해 및 노후화 대응 스마트 유지보수 기술개발)과 2019년 국토교통부의 재원으로 국토교통과학기술진흥원의 지원 (Grant 19CTAP-C153033-01)으로 수행된 연구임.

참고문헌

  1. Jang, S. Y., and Choi, S. S. (2014), Crack and Damage Patterns of Concrete Track of Kyeong-Bu High-Speed Railways, Proceedings of the 2014 autumn conference and annual meeting of the Korean Society for Railway, KSR2014S278.
  2. Freudenstein, S. RHEDA 2000® (2010), Ballastless track systems for high-speed rail applications. International Journal of Pavement Engineering, 11(4), 293-300. https://doi.org/10.1080/10298431003749774
  3. Gautier, P.-E. (2015), Slab track: Review of existing systems and optimization potential including very high speed, Construction and Building Materials, 92, 9-15. https://doi.org/10.1016/j.conbuildmat.2015.03.102
  4. Ren, J., Yang, R., Wang, P., Yong, P., and Wen, C. (2014), Slab upwarping of twin-block slab track on subgrade-bridge transition section. Journal of Transportation Research Board, 2448(1), 115-124. https://doi.org/10.3141/2448-14
  5. Zhu, S., and Cai, C. (2014), Interface damage and its effect on vibrations of slab track under temperature and vehicle dynamic loads. International Journal of Non-Linear Mechanics, 58, 222-232. https://doi.org/10.1016/j.ijnonlinmec.2013.10.004
  6. Zhu, S., Wang, M., Zhai, W., Cai, C., Zhao, C., Zeng, D., and Zhang, J. (2018), Mechanical property and damage evolution of concrete interface of ballastless track in high-speed railway: Experiment and simulation, Construction and Building Materials, 187(30), 460-473. https://doi.org/10.1016/j.conbuildmat.2018.07.163
  7. Zhong, Y., Gao, L., and Zhang, Y. (2018), Effect of daily changing temperature on the curling behavior and interface stress of slab track in construction stage. Construction and Building Materials, 185, 638-647. https://doi.org/10.1016/j.conbuildmat.2018.06.224
  8. Bishko, A. V., Samokrutov, A. A., and Shevaldykin, V. G. (2008), Ultrasonic echo-pulse tomography of concrete suing shear waves low-frequency phased antenna arrays, 17th World Conference on Nondestructive Testing, 25-28, Oct 2008, Shanghai, China.
  9. Haza, A. O., Samokrutov, A. A., and Samokrutov, P. A. (2013), Assessment of concrete structures using the Mira and Eyecon ultrasonic shear wave devices and the SAFT-C image reconstruction technique, Construction and Building Materials, 38, 1276-1291. https://doi.org/10.1016/j.conbuildmat.2011.06.002
  10. Choi, P., Kim, D.-H., Lee, B.-H., and Won, M. C. (2016), Application of ultrasonic shear-wave tomography to identify horizontal crack or delamination in concrete pavement and bridge, Construction and Building Materials, 121, 15, 81-91. https://doi.org/10.1016/j.conbuildmat.2016.05.126
  11. Lin, S., Shams, S., Choi, H., and Azari, H. (2018), Ultrasonic imaging of multi-layer concrete structures, NDT&E International, 98, 101-109. https://doi.org/10.1016/j.ndteint.2018.04.012
  12. Chen, R., Tran, K. T., La, H. M., Rawlinson, T., and Dinh, K. (2022), Detection of delamination and rebar debonding in concrete structures with ultrasonic SH-waveform tomography, Automation in construction, 133, 104004. https://doi.org/10.1016/j.autcon.2021.104004
  13. Kee, S.-H., and Lee, J.-W. (2019), Comparison of non-destructive evaluation methods for condition assessment of TCL/HSB in railway concrete slab: ultrasonic tomography and multi-channel elastic wave measurements, Proceedings of the 2019 autumn conference and annual meeting of the Korean Society for Railway, KSR2019S130.
  14. Marklein, R., Mayer, K., Hannemann, R., Krylow, T., Balasubramanian, K., Langenberg, K. J., and Schmitz, V. (2002) Linear and nonlinear inversion algorithms applied in nondestructive evaluation, Inverse Problems, 18(6), Number 6, 1733. https://doi.org/10.1088/0266-5611/18/6/319
  15. Zhu, W.-F., Chen, X.-J., Li, Z.-W., Meng, X.-Z., Fan, G.-P., Shao, W., and Zhang, H.-Y. (2019), A SAFT Method for the Detection of Void Defect inside a Ballastless Track Structure Using Ultrasonic Array Sensors, Sensors, 19(21), 4677. https://doi.org/10.3390/s19214677
  16. Otsu, N. (1979). A Threshold Selection Method from Gray-Level Histograms. IEEE Transactions on Systems, Man, and Cybernetics, 9(1), 62-66. https://doi.org/10.1109/TSMC.1979.4310076