Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

A Study on the Change of Tensile Force of Friction Type Anchor under Shear Deformation of Ground

지반의 전단변형에 따른 마찰형 앵커의 긴장력 변화에 대한 연구

  • You, Min-Ku (Dept. of Civil and Transportation Engrg., Ajou Univ.) ;
  • Kwon, O-Il (Dept. of Infrastructure Safety Research, Korea Institute of Civil Engrg. and Building Technology) ;
  • Lee, Sang-Duk (Dept. of Civil and Transportation Engrg., Ajou Univ.)
  • 유민구 (아주대학교 건설교통공학과) ;
  • 권오일 (한국건설기술연구원 인프라안전연구본부) ;
  • 이상덕 (아주대학교 건설교통공학과)
  • Received : 2018.02.28
  • Accepted : 2018.04.11
  • Published : 2018.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

When deformation occurs on slope reinforced with anchor, shear stress and bending stress are applied on the shear surface along the slip surface and increase of the shear deformation causes the tension force variation of the anchor. In this study, shear test was performed by measuring the tension force of the anchor by inducing shear deformation in vertical direction of the anchor using a large-scale direct shear test equipment in order to confirm the tension force variation of the anchor induced by shear deformation. The shear test was performed for 8 conditions which were classified according to the anchor reinforcement, separation distance (1D, 2D, 4D) from the shear surface to bonded part and the lateral-pressure condition (0.1 MPa, 0.2 MPa) of adjacent ground. As a result of the shear test, it was found that the separation distance and the lateral-pressure condition affect the shear force of the ground reinforced by anchor and the tension force of the anchor, and experimentally verified that the shear force variation is related to axial force variation of the anchor head and tip. Therefore, it was confirmed that the behavior of the bonded part induced by the shear deformation can be indirectly predicted by analyzing the tendency of the tension force variation of the anchor head.

앵커가 보강된 비탈면에 활동이 발생한 경우에는 활동면을 따라 전단면에 전단응력과 휨 응력이 작용하게 되고, 전단변형의 증가는 앵커의 긴장력 변화를 야기한다. 본 연구에서는 전단에 따른 앵커의 긴장력 변화를 확인하기 위해 앵커의 수직방향으로 전단변형을 유발하여 앵커의 긴장력을 측정하는 방법으로 대형 직접전단시험기를 통해 전단시험을 수행하였다. 전단시험은 앵커 설치 유무, 정착부에서 전단면까지의 이격거리(1D, 2D, 4D) 및 측압(0.1MPa, 0.2MPa)을 변수로 총 8가지 조건에 대해 시험을 실시하였다. 전단시험 결과, 이격거리와 주변지반의 측압은 앵커가 설치된 모형 지반의 전단력 및 앵커의 긴장력에 영향을 미치는 것으로 나타났으며, 전단력 변화는 앵커 두부 및 선단부의 축력변화와 관련이 있음을 규명하였다. 따라서 앵커 두부에서의 긴장력 변화 경향을 분석함으로써, 간접적으로 앵커 정착부에서의 전단변형에 따른 거동을 예측할 수 있음을 확인하였다.

Keywords

References

  1. Federal Highway Administration (1999), "Ground Anchors and Anchored Systems", pp.4-10, pp.46-77.
  2. Hong, C. H. (2017), "Analytical Evaluation on Soil Slope Reinforced by Pressure Grouted Protrusion Type Soil Nailing", Journal of the Korean Geotechnical Society, Vol.33, No.7, pp.5-16. https://doi.org/10.7843/KGS.2017.33.7.5
  3. Hong, C. H. (2018), "Study on the Shear Behavior of the Pressurized Soil Nailing system Using Expandable Paker System", Ph D Thesis, Ajou University, pp.66-77.
  4. Hwang, Y. and Lee, S. D. (2015), "The Earth Pressure on the Rigid Wall Depending on the Separation Distance during the Adjacent Ground Excavation", International Journal of Geo-Engineering, Volume 6, Paper no. 3, DOI 10.1186/s40703-014-0003-y
  5. Jeong, H. S., Han, K. S., and Lee, Y. S. (2017), "Measurement of Retaining Tensile Load with the Relative Displacement Detector of Ground Anchors", Journal of the Korean Geotechnical Society, Vol.33, No.10, pp.59-69.
  6. Kim, H. T. (2015), "A Study of the Knee Brace Slope Anchor Tendon Loss", Master Thesis, Kyungpook National University, pp.7-11.
  7. Kim, J. H. and Jeong, H. S. (2014), "Characteristics of Multi Load Transfer Ground Anchor System", Journal of Korean Tunnelling and Underground Space Association, Vol.16, No.01, pp.25-50. https://doi.org/10.9711/KTAJ.2014.16.1.025
  8. Kim, J. H. and Jeong, H. S. (2016), "Ground Anchor Method for Engineers", CIR publication, pp.9-102.
  9. Kim, Y. M., Cho, K. W., Kim, W. K., and Kim, H. M. (2004), "Load Distribution and Pullout Capacity of Compression Anchors", Journal of the Korean Society of Civil Engineers, pp.4219-4224.
  10. Lee, B. J. and Lee, J. K. (2015), "Evaluation of Loss of Prestress Force of Tensile Anchor by Long Term Measurement", Journal of the Korean Geo-Environmental Society, pp.15-22.
  11. Lee, S. D. (2016), "Earth Pressure Theory", CIR publication, pp. 177-191.
  12. Lee, S. D. (2000), "Principle and Method of Basic Soil Test", Saeron publication, pp.36-277.
  13. Marchal, J. (1984), "Reinforcement Des Sols Par Clouage - Etude Experimentale en Laboratoire", Proc Int Conf on In-situ Soil and Eock Eeinforcement, Paris, pp.275-278.
  14. Ministry of Land, Transport and Maritime Affairs of Korea (2009), "Manual for Design, Construction and Maintenance of Ground Anchors", pp.86-101.
  15. Ortigao, J. A. R., Palmeira, E. M., and Zirlis, A. C. (1995), "Experience with Soil Nailing in Brazil: 1970-1994", Proceeding of the Institution of Civil Engineers : Geotechnical Engineering, Vol.113, Issue 2, pp.93-106. https://doi.org/10.1680/igeng.1995.27589
  16. Sabatini, P. J., Pas, D. G., and Bachus, R. C. (1999), "Geotechnical Engineering Circular No. 4 Ground Anchors and Anchored Systems", FHWA-SA-99-015, Office of Bridge Technology Federal Highway Administration, Washington, D.C, pp.6-28.
  17. Schlosser, F. (1982), "Behavior and Design of Soil Nailing", Proc., Symposium for Recent Developments in Ground Improvement Techniques, Bangkok, Thailand, pp.399-413.
  18. Sung, H. J. (2012), “Tension Force Monitoring of Ground AnchorUsing Fiber Optic Sensors Embedded Tendon”, Ph D Thesis,Chonnam National University, pp.69-144.
  19. Sung, H. J., Kim, Y. S., Kim, J. M., and Park, G. H. (2011), “Tension Force Monitoring of Tension Type Ground Anchor Using Optical FBG Sensors”, Journal of the Korean Geotechnical Society, Vol.27, No.6, pp.17-26. https://doi.org/10.7843/kgs.2011.27.6.017

Cited by

  1. 앵커 긴장력 변화에 따른 비탈면 유지관리 연구 vol.30, pp.4, 2020, https://doi.org/10.9720/kseg.2020.4.673