Journal of the Computational Structural Engineering Institute of Korea (한국전산구조공학회논문집)

Computational Structural Engineering Institute of Korea (한국전산구조공학회)
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Experimental Evaluation of Prestress Force in Tendons for Prestressed Concrete Girders using Sensors

계측 센서를 활용한 PSC 거더 텐던의 긴장력 측정 실험

  • Shin, Kyung-Joon (Department of Civil Engineering, Chungnam National Univ.) ;
  • Park, Young-Ung (Department of Civil Engineering, Pukyung National Univ.) ;
  • Lee, Seong-Cheol (Department of NPP Engineering, KEPCO International Nuclear Graduate School) ;
  • Kim, Yun Yong (Department of Civil Engineering, Chungnam National Univ.) ;
  • Lee, Hwan-Woo (Department of Civil Engineering, Pukyung National Univ.)
  • 신경준 (충남대학교 토목공학과) ;
  • 박영웅 (부경대학교 토목공학과) ;
  • 이성철 (국제원자력대학원대학교 원자력산업학과) ;
  • 김윤용 (충남대학교 토목공학과) ;
  • 이환우 (부경대학교 토목공학과)
  • Received : 2015.10.26
  • Accepted : 2015.11.30
  • Published : 2015.12.29
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Abstract

The prestressing force has not been managed after construction nevertheless it is one of the importrant factors that maintain the structural safety of PSC girder bridges. The prestressing force is just measured during construction using jacking device and after that, it can not be managed practically. For this reason, this study investigated the measurements of prestress using embedded sensors that can be available now with an ultimate goal to propose smart prestressed girders that can measure the prestress from the birth to the end of service life. 4 types of sensors were installed on the small prestressed girders, and the applicability and the accuracy of those sensors were tested while the prestress was applied to the girders. The results show that a center-hole type loadcell has a tendency to measure a prestressing force higher than a reference value, especially when it is loaded with an eccentricity. a EM sensor shows several advantages that has a good practical accuracy, that can be installed anyplace along the tendons.

프리스트레스(PS) 긴장재의 긴장력 관리는 거더 성능관리에 있어 매우 중요한 항목이나 현재는 시공시 설계 긴장력의 도입 여부만을 검증한 후 공용시에는 그 관리가 이루어지지 않는 실정이다. 이에 본 연구에서는 PSC 거더의 제작단계에서부터 공용시까지 생애주기 동안의 긴장력 관리가 가능한 PSC 거더를 제안하기 위한 기초 연구로서, 현재의 기술수준으로 사용 가능한 센서들을 이용하여 PS 긴장력을 측정하는 실험 연구를 수행하였다. 소규모 거더를 제작하여 4종류의 센서를 설치하였고, 긴장력을 도입하면서 각 센서들의 적용성과 정확성을 평가하였다. 실험결과에 따르면, 중공로드셀은 편심하중이 작용하는 경우 기준값보다 하중을 높게 평가하는 경향이 있었다. EM 센서는 실용이 가능한 정확도를 보여주었으며, 콘크리트 내부의 긴장재를 따라 어느 위치에서도 설치할 수 있다.

Keywords

References

  1. Baudendistel, T.A,, Tunner, M.L. (2007) A Novel Inverse-Magnetostrictive Force Sensor, IEEE Sensor J., 7(2), pp.245-250. https://doi.org/10.1109/JSEN.2006.886876
  2. Burn, N.H., Helwig, T., Tsujimoto, T. (1991) Effective Prestress Force in Continuous Post-Tensioned Beams with Unbonded Tendons, ACI Struct. J., 88(1), pp.84-90.
  3. Chaki, S., Bourse, G. (2009) Stress Level Measurement in Prestressed Steel Strands using Acoustoelastic Effect, Exp. Mech., 49, pp.673-681. https://doi.org/10.1007/s11340-008-9174-9
  4. Chen, H.L., Wissawapaisal, K. (2001) Measurement of Tensile Forces in a Seven-Wire Prestressing Strands using Stress Waves, ASCE J. Eng. Mech., 127(6), pp.599-606. https://doi.org/10.1061/(ASCE)0733-9399(2001)127:6(599)
  5. Civjan, S.A., Jirsa, J.O., Carrasquillo, R.L., Fowler, D.W. (1995) Method to Evaluate Remaining Prestress in Damaged Prestressed Bridge Girders, Research Report No.1370-2, Center for Transportation Research, Bureau of Engineering Research, The University of Texas, Austin.
  6. Kim, B.H., Joh, C.B., Lee, D.H. (2013) The Using Permeability of Magnetic Flux using Measured Elastic Wave Velocity. J. Earthq. Eng.. 17(5A), pp.219-225.
  7. Kim, B.H., Jang, J.B., Lee, H.P., Lee, I.K. (2012) Estimation of Prestressed Tension on Grouted PSC Tendon using Measured Elastic Wave Velocity, J. Korean Soc. Civil Eng., 32(5A), pp.289-297. https://doi.org/10.12652/Ksce.2012.32.5A.289
  8. Kim, J.K., Park, J.Y., Zhang, A., Lee, H.W., Park, S.H. (2015) Tensile Force Monitoring for Pre-Stress Tendon of PSC Girder by Incorporating FBG and EM Sensor, Nondestructive Characterization of Materials, NDCM 2015, USA.
  9. Kim, J.T., Hong, D.S., Park, J.H., Cho, H.M. (2008) Vibration-Based Monitoring of Prestress-Loss in PSC Girder Bridges, J. Comput. Struct. Eng. Inst. Korea, 21(1), pp.83-90.
  10. Lin, T.Y. (1963) Design of Prestressed Concrete Structures, John Wiley & Sons, USA.
  11. Miyamoto, A., Tei, K., Nakamura, H., Bull, J.W. (2000) Behavior of Prestressed Beam Strengthed with External Tendons, J. Struct. Eng., ASCE, 126(9), pp.1033-1044 https://doi.org/10.1061/(ASCE)0733-9445(2000)126:9(1033)
  12. Nabil, F.G., Brian, R. (1996) Dynamic Characteristics of Post-Tensioned Girders with Web Openings, J. Struct. Eng., 122, pp.643-650. https://doi.org/10.1061/(ASCE)0733-9445(1996)122:6(643)
  13. Pessiki, S., Kaczinski, M., Wescott, H.H. (1996) Evaluation of Effective Prestress Force in 28-Year-Old Prestressed Concrete Bridge Beams, PCI J., 41(6), pp.78-89 https://doi.org/10.15554/pcij.11011996.78.89
  14. Saiidi, M., Douglas, B., Feng, S. (1994) Prestress Force Effect on Vibration Frequency of Concrete Bridges, J. Struct. Eng., ASCE, 120(7), pp.2233-2241. https://doi.org/10.1061/(ASCE)0733-9445(1994)120:7(2233)
  15. Saiidi, M., Douglas, B., Feng, S. (1994) Prestress Force Effect on Vibration Frequency of Concrete Bridges, J. Struct. Eng., ASCE, 120(7), pp.2233-2241. https://doi.org/10.1061/(ASCE)0733-9445(1994)120:7(2233)
  16. Sharif, A., Taher, S.E.F., Basu, P.K. (1993) Time-dependent Losses in Prestressed Continuous Composite Beams, J. Struct. Eng., ASCE, 119(11), pp.3151-3168 https://doi.org/10.1061/(ASCE)0733-9445(1993)119:11(3151)
  17. Wang, M.L., Chen, Z. (2000) Magneto-Elastic Permeability Measurement for stress monitoring in steel tendons and cables, Proc. of the SPIE 7th Annual Symposium on Smart Structures and Materials, Health Monitoring of the Highway Transportation Infrastructure, 3995, pp.492-500.

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  1. Construction Condition and Damage Monitoring of Post-Tensioned PSC Girders Using Embedded Sensors vol.17, pp.8, 2017, https://doi.org/10.3390/s17081843
  2. Damage Detection with FBG Sensors for Pre-Stress Concrete Girders vol.737, pp.1662-9795, 2017, https://doi.org/10.4028/www.scientific.net/KEM.737.454
  3. Magnetic Hysteresis Monitoring according to the Change of Tensile Force and Steel Class of PS Tendons vol.31, pp.2, 2018, https://doi.org/10.7734/COSEIK.2018.31.2.115