Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
권호 표지
DOI QR코드

DOI QR Code

Measurement of ground behaviour due to tunnelling using No-target program in laboratory model test

실내모형시험에서 No-target 프로그램을 이용한 터널 굴착으로 인한 지반거동 측정

  • Lee, Jong-Hyun (Dept. of Civil Engineering, Seoul National University of Science and Technology) ;
  • Lee, Chang-No (Dept. of Civil Engineering, Seoul National University of Science and Technology) ;
  • Lee, Yong-Joo (Dept. of Civil Engineering, Seoul National University of Science and Technology)
  • 이종현 (서울과학기술대학교 건설시스템공학과) ;
  • 이창노 (서울과학기술대학교 건설시스템공학과) ;
  • 이용주 (서울과학기술대학교 건설시스템공학과)
  • Received : 2019.03.29
  • Accepted : 2019.05.02
  • Published : 2019.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

It is very important to understand and analyze the interactive behaviour between ground and adjacent structures due to tunneling. With many technological advancement in modern society, numerous methods for analyzing the interactive behaviour are used in a wide range of civil engineering fields. Close range photogrammetry is mainly being used in the field of geotechnical engineering and research on measuring methods associated with GeoPIV has been currently increased. Originally, the close range photogrammetry using target points and aluminum rods for VMS (Vision Measurement System) program has been used. However, applying this has a problem that external errors can be occurred because the target points are artificially installed by hand, and if the grid between points is being wider or narrower, deficient data can be obtained. Therefore, in this study, MATLAB-based No-target program that can analyze displacement without using target was developed. Additionally, this study focused on comparison and verification with existing program through numerical analysis and laboratory model test. Three cases of Greenfield condition, Strip foundation, and Pile foundation were analyzed. From results of VMS program and No-target program, the error rate and reliability of the total displacement and the vertical displacement were analyzed. It was also compared and verified through the finite element numerical program, PLAXIS.

터널 굴착으로 인한 지반 및 인접 구조물의 거동을 이해하고 분석하는 것은 매우 중요하며, 이는 현대사회에서의 과학기술의 발전과 함께 토목공학 분야에서 폭넓게 활용되고 있다. 근거리 사진계측기법은 지반공학 분야에서 주로 쓰이고 있으며, 최근 GeoPIV 등을 이용한 계측기법의 연구가 증가하고 있는 추세이다. 본래에는 지반의 거동을 계측하여 시각화하는 방법으로 알루미늄 봉과 타겟 포인트를 이용한 VMS 프로그램이 주로 사용되어 왔다. 하지만 이러한 방법을 적용할 경우, 타겟 포인트가 손에 의해 인위적으로 설치되기 때문에 외부적인 오차가 발생할 수 있다. 또한 포인트 사이의 그리드가 넓거나 좁을 경우 희박한 데이터가 도출될 수 있는 문제점을 안고 있다. 따라서 본 연구에서는 타겟의 사용 없이 변위를 분석할 수 있는 MATLAB 기반의 No-target 프로그램을 개발하였고 수치해석과 실내 모형시험을 통해 기존의 프로그램과의 비교 및 검증에 초점을 맞추었다. 연구 내용으로는 greenfield condition, strip foundation, pile foundation 3가지 Case에 대하여 실내 모형시험을 실시하였으며, VMS 프로그램과 No-target 프로그램의 결과로부터 total displacement와 vertical displacement의 오차율을 분석하였다. 또한 유한요소 수치해석 프로그램인 PLAXIS를 통하여 실내 모형시험과의 결과와 비교 및 검증하였다.

Keywords

TNTNB3_2019_v21n3_397_f0001.png 이미지

Fig. 1. Example of plane-strain (Potts et al., 2014)

TNTNB3_2019_v21n3_397_f0002.png 이미지

Fig. 2. Settlement profile above a tunnel in soft ground and VL (Atkinson, 2016)

TNTNB3_2019_v21n3_397_f0003.png 이미지

Fig. 3. Concept of close range photogrammetry

TNTNB3_2019_v21n3_397_f0004.png 이미지

Fig. 4. Target point

TNTNB3_2019_v21n3_397_f0005.png 이미지

Fig. 5. Mesh generation for closes range photogrammetry

TNTNB3_2019_v21n3_397_f0006.png 이미지

Fig. 6. Procedure of No-target program in MATLAB

TNTNB3_2019_v21n3_397_f0007.png 이미지

Fig. 7. Calculation of displacement vector in MATLAB

TNTNB3_2019_v21n3_397_f0008.png 이미지

Fig. 8. Outline of the laboratory model test

TNTNB3_2019_v21n3_397_f0009.png 이미지

Fig. 9. Model tunnel device components

TNTNB3_2019_v21n3_397_f0010.png 이미지

Fig. 10. Determination of allowable load and sand drop device

TNTNB3_2019_v21n3_397_f0011.png 이미지

Fig. 11. Sand line (black + white) model test

TNTNB3_2019_v21n3_397_f0012.png 이미지

Fig. 12. Black sand model test using aluminum rod (VMS program)

TNTNB3_2019_v21n3_397_f0013.png 이미지

Fig. 13. Mixed sand model test (No-target program)

TNTNB3_2019_v21n3_397_f0014.png 이미지

Fig. 14. 2D mesh generation

TNTNB3_2019_v21n3_397_f0015.png 이미지

Fig. 15. Ground settlements of greenfield condition

TNTNB3_2019_v21n3_397_f0016.png 이미지

Fig. 16. Ground settlements of strip foundation

TNTNB3_2019_v21n3_397_f0017.png 이미지

Fig. 17. Ground settlements of pile foundation

TNTNB3_2019_v21n3_397_f0019.png 이미지

Fig. 18. Total displacement vector according to VL for greenfield condition

TNTNB3_2019_v21n3_397_f0020.png 이미지

Fig. 19. Total displacement vector according to VL for strip foundation

TNTNB3_2019_v21n3_397_f0021.png 이미지

Fig. 20. Total displacement vector according to VL for pile foundation

TNTNB3_2019_v21n3_397_f0022.png 이미지

Fig. 21. Measurement point for a comparison

TNTNB3_2019_v21n3_397_f0023.png 이미지

Fig. 22. Vertical displacement contour in FEM

TNTNB3_2019_v21n3_397_f0024.png 이미지

Fig. 23. Comparison between model test and FEM for vertical displacement

Table 1. Ground material properties

TNTNB3_2019_v21n3_397_t0001.png 이미지

Table 2. Properties of foundation

TNTNB3_2019_v21n3_397_t0002.png 이미지

Table 3. Displacement vectors measured by VMS and No-target program

TNTNB3_2019_v21n3_397_t0003.png 이미지

Table 4. Vertical displacement contours measured by VMS and No-target program

TNTNB3_2019_v21n3_397_t0004.png 이미지

Table 5. Calculation of error rate

TNTNB3_2019_v21n3_397_t0005.png 이미지

Table 6. Error rate according to test Cases

TNTNB3_2019_v21n3_397_t0006.png 이미지

References

  1. Allersma, H.G.B. (1990), "On line measurement of soil deformation in centrifuge tests by image processing", Proceedings of the International Conference on Experimental Mechanics, Copenhagen, pp. 1739-1748.
  2. Allersma, H.G.B., Stuit, H.G., Holscher, P. (1994), "Using image processing in soil mechanics", Proceedings of the 12th International Conference, Soil Mechanics, New Delhi, pp. 1341-1344.
  3. Atkinson, J. (2016), The mechanics of soils and foundations, CIR, Seoul, pp. 538-539.
  4. Das, B.M. (2010), Principles of geotechnical engineering, CENGAGE Learning, Stanford, pp. 65.
  5. Kong, S.M., Lee, Y.J. (2016), "A study on soil behaviour due to tunneling under embedded pile using close range photogrammetry", Journal of Korean Tunnelling and Underground Space Association, Vol. 18, No. 4. pp. 365-376. https://doi.org/10.9711/KTAJ.2016.18.4.365
  6. Kwon, H.J., Kim, D.S., Park, J.B., Jung, S.K. (2007), Foundation engineering, Goomibook, Seoul, pp. 204-206.
  7. Lee, H.G. (2017), Investigation of ground behavior according to ground water locations due to Tunnelling under shallow foundation in sand, Master Thesis, The Graduate School, Seoul National University of Science and Technology, pp. 15.
  8. Lee, J.H. (2014), Model tunnel excavation using close range photogrammetric technique for tunnel roof reinforcement, Master Thesis, The Graduate School, Seoul National University of Science and Technology, pp. 24-26.
  9. Lee, J.H., Lee, Y.J. (2014), "Analysis of ground behavior for model tunnel excavation with pipe roof reinforcement using close range photogrammetric technique", Journal of Korean Tunnelling and Underground Space Association, Vol. 16, No. 4, pp. 387-402. https://doi.org/10.9711/KTAJ.2014.16.4.387
  10. Lee, S.D. (2017), Settlement of ground, CIR, Seoul, pp. 269-274.
  11. Lee, Y.J. (2006), "Comparison of shallow model tunnel test using image processing and numerical analysis", Journal of the Korean Geotechnical Society, Vol. 22, No. 7, pp. 5-12.
  12. Lee, Y.J., Bassett, R.H. (2006), "Application of a photogrammetric technique to a model tunnel", Tunnelling and Underground Space Technology, Vol. 21, No. 1, pp. 79-95. https://doi.org/10.1016/j.tust.2005.06.005
  13. Lee, Y.J., Song, K.J. (2010), "Shearing characteristics of aluminium rods using plane strain - Shear box test and close range photogrammetric technique", Journal of the Koran Geotechnical Society, Vol. 26, No. 8, pp. 5-14.
  14. Oh, D.W., Lee, Y.J. (2017) "Analysis of pile load distribution and ground behavior depending on vertical offset between pile tip and tunnel crown in sand through laboratory model test", Journal of Korean Tunnelling and Underground Space Association, Vol. 19, No. 3, pp. 355-373. https://doi.org/10.9711/KTAJ.2017.19.3.355
  15. Peck, R.B. (1969), "Deep excavation and tunneling in soft ground", Proceedings of the 7th International Conference on Soil Mechanics and Foundation Engineering, Mexico, State-of-the-art Reports, pp. 311-375.
  16. Potts, D., Axelsson, K., Grande, L., Schweiger, H., Long, M. (2014), Guideliness for the use of advanced numerical analysis, CIR, Seoul, pp. 18-19.
  17. Stanier, S.A., Blaber, J., Take, W.A., White, D.J. (2015), "Improved imaged-based deformation measurement for geotechnical applications", Canadian Geotechnical Journal, Vol. 53, No. 5, pp. 727-739. https://doi.org/10.1139/cgj-2015-0253