DOI QR코드

DOI QR Code

Application of Prefabricated Retaining Walls with Steel Lagging

강재 요소를 적용한 조립식 흙막이 벽체에 관한 연구

  • Received : 2011.09.01
  • Accepted : 2015.09.23
  • Published : 2015.12.01

Abstract

It has been known that the conventional retaining wall system with timber lagging and H pile has several problems such as the irregular gap between H-piles, cutting or adding to standard timber, back fill over first step excavation, and especially break-down accident at the disjoint of wall system. In the practical excavation, these problems may lead to worker's accident and the inefficiency of construction economy. To solve the above problems, a new method using prefabricated retaining wall was proposed and verified. The characteristics of the new method is to replace timber wall as free-sliding steel-lagging and connector. To check its verification and application, laboratory tests such as bending strength, tensile strength, and fatigue strength were carried out. Also, a pilot test in the field and numerical simulations under various ground conditions were performed. From the researches, it is found that the prefabricated retaining wall plate can be superior to the conventional timber lagging plate in the strength. It is also found that the proposed methods can be effective in the reuse of retaining wall plate and safe in the disjoint of wall system. Finally, it is desired that the proposed method will be effective in the reduction of the imported timbers and helpful in the safety of retaining wall construction.

H-pile과 목재 토류판을 사용하는 흙막이 공법은 오랜 기간 굴착공사에서 사용되어 온 공법이지만 H-pile 사이의 간격이 일정치 않아 규격화된 목재를 절단하거나 덧대기 공정이 추가되는 문제점이 있다. 또한, 시방규정상 3회 재사용을 위한 목재 회수시 안전사고의 위험이 따르게 되며 이러한 이유로 목재를 회수치 않고 지중에 매몰하여 여러 차례 방송매체의 지적을 받은 바 있다. 이 연구에서는 이상의 문제점을 보완하기 위하여 기존의 목재 토류판을 대신하여 강재 요소를 적용하는 방안을 제시하였다. 강재 흙막이 구조체는 자유 확폭과 개별 흙막이 구조체를 연결하는 커넥터를 통해 시공 편의성 및 재활용을 위한 회수가 가능한 것이 특징이다. 또한, 해체 시 커넥터를 통한 구조체간의 연결성으로 지중인력투입없이 해체가 가능하다. 이러한 흙막이 구조체의 강도특성을 분석하기 위해 UTM장비를 사용하여 휨 강성시험, 반복 사용의 능력을 확인하기위한 피로 강도시험, 그리고, 흙막이 구조체의 회수 시 연결부 구조체의 성능을 확인하기위한 인장 강도시험을 수행하였다. 또한, 장점으로 부각된 내용이 현장에서 실제 가능한지 여부를 확인하기 위한 현장시험과 다양한 지반조건에 따른 수치해석을 통해 현장 적용성을 평가하였다. 연구결과, 구조적 특성뿐만 아니라 설치 및 해체시의 시공 편의성이 매우 탁월한 것으로 나타났으며 향후 구조체의 재사용과 함께 시공 경제성 증진에도 크게 기여할 것으로 판단된다. 특히, 다단굴착시 굴착배면에 흙막이 구조체가 밀착되어 설치가 가능한 점은 기존 공법에서 지적되어 온 배면지반의 뒷채움 불량이 발생할 여지가 없어 시공 및 시공 후 시설물의 안전성 증진에 크게 기여할 수 있을 것으로 판단된다.

Keywords

References

  1. Cho, W. G. (2007). Study on the Engineering Characteristics after improvement of Yang-San Mulkum's Soft Ground, Master's Degree. Dissertation, University of Konyang, Nonsan, Korea, pp. 24-27.
  2. Choi, C. S., Jeong, S. S. and Kim, S. I. (1997). "Backanalysis of the sequential behavior of earth retaining walls using direct search method." J. of Korean Society of Civil Engineers, KSCE, Vol. 17, No. 3-6, pp. 651-663.
  3. Choi, J. S. and Yun, E. J. (2007). "Application of steel material to intensify the construction capacity and convenience in the wall-excavation of Korea." Proc. of Autumn Conf. on Korea Association of Professional Engineers in Soil Mechanics and Foundation Engineering, pp. 261-268.
  4. Choi, J. S., Hong, J. W. and Yun, J. S. (2011). "Applications of steel elements for recycling of conventional retaining wall structure", Proc. of Spring Conf. on Korean Geotechnical Society, pp. 421-430.
  5. Choi, J. S., Yoon, J. S., Son, S. G. and Sim, J. U. (2010). "Practical applications of new land-side protection wall method using steel pile, steel panel, and steel guide-post." Proc. of Autumn Conf. on Korea Association of Professional Engineers in Soil Mechanics and Foundation Engineering, pp. 229-236.
  6. Choi, Y. Y. (2010). Practical Verifications for the Advanced Retaining Walls of Waterproofing and Structural Characteristics, Master's Degree. Dissertation, University of Seokyeong, Seoul, Korea.
  7. Gere, J. M. and Goodno, B. J. (2011). Mechanics of Materials 7th Edition, CENGAGE Learning, Boston, M.A., pp. 985-988.
  8. Hong, B. S. (2010). "Internal fixing agent for tensile material removal type ground anchor." Proc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 35-47.
  9. Hong, J. W. (2011). Applications of Steel elements for Permanent Re-use Retaining Wall Systems, Master's Degree. Dissertation, University of Seokyeong, Seoul (in Korean).
  10. Jeong, J. M. and Kang, H. J. (2010). "PPS (Prestressed Pipe Strut Excavation Method without Postpile)." Proc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 209-221.
  11. Jin, K. S. (2010). "IPS (Innovative Prestressed Support) Retaining Wall." PProc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 183-205.
  12. Kang, M. C. (2010). "Design and construction case of delete type soil-nail and post tension soil-nail." Proc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 3-32.
  13. Kim, J. Y., Hong, B. S. and Jeong, J. K. (2010). "A study on ground anchor technology for weak ground." Proc. of Autumn Conf. on Korea Association of Professional Engineers in Soil Mechanics and Foundation Engineering, pp. 237-246.
  14. Korean Geotechnical Society (2009). Standard of Foundation Design, Goomiseokwan, Seoul (in Korean).
  15. Seo, S. G., Gam, S. B. and Lee, D. S. (2010). "Design and construction case of steel pipe strut for grand scale excavation work." Proc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 141-158.
  16. Seok, J. W., Kim, O. Y. and Kim, M. M. (2001). "Evaluation of building settlement near braced excavation by numerical analysis." J. of Korean Society of Civil Engineers, KSCE, Vol. 21, No. 1, pp. 69-80.
  17. Shin, S. H. (2010). "QSR Nail." Proc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 73-79.
  18. Shin, Y. B. (2008). An experimental study on the effectiveness related penetration depth of stabilizing piles used as earth retaining structure method using self supported stabilizing pile, Master's Degree. Dissertation, University of Busan, Busan (in Korean).
  19. Son, M. R. (2009). "Response analysis of nearby structures to excavation-induced advancing ground movements." J. of Korean Society of Civil Engineers, KSCE, Vol. 29, No. 4, pp. 153-162.
  20. Son, S. G., Sim, J. U., Jung, L. J., Yoon, J. S. and Choi, J. S. (2011). "Field evaluation of hybrid retaining wall possible deep underground and wide excavation." Proc. of Spring Conf. on Korean Geotechnical Society, pp. 942-948.
  21. Yoo, C. S. and Kim, Y. J. (2000). "Behavior of propped walls during deep excavation." J. of Korean Society of Civil Engineers, KSCE, Vol. 20, No. 3, pp. 195-204.
  22. Yoo, J. H. and Ko, J. W. (2010). "Method of high intensity steel pipe strut(Postrut)." Proc. of Design and Construction Case Seminar of New Technology in Ground Excavation in Korean Geotechnical Society, pp. 239-252.