DOI QR코드

DOI QR Code

GFS-CFXB 내진보강법을 이용한 지진피해를 받은 R/C 건물의 내진성능 평가 및 내진보강 효과

Seismic Strengthening and Performance Evaluation of Damaged R/C Buildings Strengthened with Glass Fiber Sheet and Carbon Fiber X-Brace System

  • 투고 : 2013.08.05
  • 심사 : 2013.10.07
  • 발행 : 2013.12.31

초록

기존 강재 브레이싱 내진보강법은 정착부의 안정성 문제와 브레이싱의 국부좌굴이 발생할 문제가 있으며, 이를 방지하기 위한 추가보강으로 인해 불필요한 자중증가 등으로 경제적인 내진보강성능 확보에 어려움이 있다. 이 연구에서는 지진피해를 받은 건물에 지진피해로 인한 기존 기둥의 연성확보를 위해서 유리섬유시트(glass fiber sheet)로 래핑을 함과 동시에 기존 철골 X-브레이싱 내진보강법에 비교해서 경량의 고강도 재료로 보강 후 추가적인 중량증가가 거의 없으며, 브레이싱 압축 좌굴거동에 자유로운 탄소섬유 앵커 X-브레이싱공법(carbon fiber X-brace)을 조합한 경제적이며 효과적인 새로운 내진보강법(GFS-CFXB)을 제안하였다. 이 연구에서 제안한 GFS-CFXB공법의 유용성을 검증할 목적으로 지진피해를 받은 골조를 대상으로 반복가력에 의한 구조실험을 실시하여 내진성능 및 내진보강 효과를 검증하였다.

Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. This paper proposes a new seismic retrofit methodology combined with glass fiber sheet (GFS) and non-compression X-brace system using carbon fiber (CFXB) for reinforced concrete buildings damaged in earthquakes. The GFS is used to improve the ductility of columns damaged in earthquake. The CFXB consists of carbon fiber bracing and anchors, to replace the conventional steel bracing and bolt connection. This paper reports the seismic resistance of a reinforced concrete frame strengthened using the GFS-CFXB system. Cyclic loading tests were carried out, and the hysteresis of the lateral load-drift relations as well as ductility capacities were investigated. Carbon fiber is less rigid than the conventional materials used for seismic retrofitting, resulting in some significant advantages: the strength of the structure increased markedly with the use of CF X-bracing, and no buckling failure of the bracing was observed.

키워드

참고문헌

  1. Shin, J., Kim, J., and Lee, K., "Fragility Assessment of Damaged Piloti-Type RC Building With/Without BRB Under Successive Earthquake," Journal of the Earthquake Engineering Society of Korea, Vol. 17, No. 3, 2013, pp. 133-141. https://doi.org/10.5000/EESK.2013.17.3.133
  2. Acheim, M. and Black, E. "Effects of Prior Earthquake Damage on Response of Simple Stiffness-Degrading Structures," Earthquake Spectra, Vol. 15, No. 1, 1999, pp. 1-23. https://doi.org/10.1193/1.1586026
  3. Lee, K. and Foutch, D. A., "Performance Evaluation of Damaged Steel Frame Buildings Subjected to Seismic Loads," Journal of Structural Engineering (ASCE), Vol. 130, No. 5, 2004, pp. 588-599. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:4(588)
  4. Li, Q. and Ellingwood, B. R., "Performance Evaluation and Damage Asessment of Steel Frame Buildings under Main Shock-After Shock Earthquake Sequences," Earthquake Engineering & Structural Dynamics, Vol. 36, Issue 3, 2007, pp. 405-427. (doi: http://dx.doi.org/10.1002/eqe.667)
  5. Maeda, M., Nakano, Y., and Lee, K. S., "Post-Earthquake Damage Evaluation for R/C Buildings Based on Residual Seismci Capacity," 13th World Conference on Earthquake Engineering, Vancouver, B. C., Canada, Paper No. 1179, 2004, pp. 1179-1194.
  6. Korea Meteorological Administration, "http://www.kma.go.kr/weather/earthquake/report.jsp".
  7. Ministry of Land, Infrastructure and Transport (MLIT), "Master Plan for Maintenance and Safety of Facilities," Notice of MLIT (2002-318), 2002, 350 pp.
  8. Viswanath, K. G., Prakash, K. B., and Desai, A., "Seismic Analysis of Steel Braced Reinforced Concrete Frames," International Journal of Civil and Structural Engineering, Vol. 1, No. 1, 2010, pp. 114-122.
  9. Youssef, M. A., Ghaffarzadeh, H., and Nehdi, M., "Seismic Performance of RC Frames with Concentric Internal Steel Bracing," Engineering Structures, Vol. 29, No. 7, 2007, pp. 1561-1568. (doi: http://dx.doi.org/10.1016/j.engstruct.2006.08.027)
  10. Maheri, M. R. and Sahebi, A., "Experimental Investigation on the Use of Steel Bracing in Reinforced Concrete Frames," Proceedings of the Second International Conference on Seismic and Earthquake Engineering (Iran), 1995, pp. 775-784.
  11. Maheri, M. R. and Sahebi, A., "Use of Steel Bracing in Reinforced Concrete Frames," Engineering Structures, Vol. 19, No. 12, 1997, pp. 1018-1024. https://doi.org/10.1016/S0141-0296(97)00041-2
  12. Chang, H. Y. and Chiu, C. K., "Performance Assessment of Buckling Restrained Braces," Procedia Engineering, Vol. 14, No. 1, 2011, pp. 2187-2195. https://doi.org/10.1016/j.proeng.2011.07.275
  13. Lee, K., Wi, J., and Kim, Y., "Seismic Performance Evaluation of RC Buildings using Japanese Standard for Seismic Performance Evaluation," Proceedings of EESK Conference 2009, Vol. 13, 2009, pp. 134-137.
  14. Lee, K. S., Lee, S. H., Kim, Y. I., Wi, J. D., and Song, B. I., "Seismic Safety Evaluation of Existing Reinforced Concrete Buildings in Korea," Proceedings of the Korea Concrete Institute, 2010, Vol. 22, No. 2, pp. 363-364.
  15. Ministry of Education and Science Technology (MEST), "Guideline for Seismic Capacity Evaluation and Seismic Strengthening of Existing School Buildings," MEST, 2011, 60 pp.
  16. Lee, K. S., Choi, H., Han, S. W., and Lee, S. B., "A Practical Rapid Screening Method for Evaluating the Seismic Capacity of Low-rise Reinforced Concrete Buildings," Journal of Advanced Concrete Technology, Vol. 9, No. 3, 2010, pp. 301-314. (doi: http://dx.doi. org/10.3151/jact.9.301)
  17. Lee., K., et al., "Seismic Performance Evaluation of Korean R/C School Buildings Using Pseudo Dynamic Test Method," Proceedings of the Korean Concrete Institute, Vol. 24, No. 1, 2012, pp. 100-101.
  18. Lee, K., Choi, H., and Yi, W., "Earthquake Damage Ratio Estimation and Seismic Capacity Evaluation of Existing RC Buildings in Korea," Journal of the Architectural Institute of Korea, Vol. 18, No. 1, 2002, pp. 11-21.
  19. Japan Building Disaster Prevention Association., Standard for Damage Level Classification, Tokyo, Japan (in Japanese), 2001, 250 pp.
  20. Japan Building Disaster Prevention Association, "Standard for Seismic Evaluation of Existing Reinforced Concrete Buildings," Tokyo, Japan (in Japanese), 1977 (Revision in 1990 and 2003), 250 pp.
  21. Park, R., "Evaluation of Ductility of Structures and Structural Assemblages from Laboratory Testing," Bulletin of the New Zealand National Society for Earthquake Engineering, Vol. 22, No. 3, 1989, pp. 155-166.