대한토목학회논문집 (KSCE Journal of Civil and Environmental Engineering Research)

  • 제39권6호
  • /
  • Pages.789-799
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  • 2019
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  • 1015-6348(pISSN)
  • /
  • 2799-9629(eISSN)
대한토목학회 (Korean Society of Civil Engeneers)
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벽체 강성에 따른 토사유입차단판의 최적 길이 산정에 관한 실험적 연구

An Experimental Study on the Estimation of Optimum Length of Soil Flow Protector with Wall Stiffness

  • 유재원 (부산대학교 생산기술연구소) ;
  • 서민수 (부산대학교 생산기술연구소) ;
  • 손수원 (부산대학교 지진방재연구센터) ;
  • 임종철 (부산대학교 사회환경시스템공학과)
  • 투고 : 2019.06.04
  • 심사 : 2019.10.02
  • 발행 : 2019.12.01
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초록

교대, 통로박스 등 말뚝기초로 지지된 구조물에서는 침하가 거의 발생하지 않지만, 구조물 저면 하부에는 공동이 발생하게 된다. 이에 따른 문제점으로는 측면지반에서 공동으로 유출된 토사에 의해 구조물 측면 지반의 침하를 가속화하여 더 큰 침하가 발생하게 된다. 따라서 말뚝 기초로 지지된 구조물 하부의 공동 발생으로 인한 문제점을 예방하고자 구조물의 측면에 쉽게 설치가 가능한 토사유입차단판(soil Flow Protector; 이하 'FLP')이 개발되었다. 본 연구에서는 FLP의 침하감소 효과를 입증하고 최적 길이를 산정하고자 실내모형실험을 수행하였고, 그 결과 FLP의 설치함으로서 측면지반의 침하량이 감소하고 공동으로의 토사 유출을 방지하였고, FLP의 강성이 작으면 상부의 토압은 정지 또는 주동영역이 되어 안정성에 유리하지 않지만, 충분히 크면 상부의 토압은 수동영역이 되어 안정성에 유리하다. 또한 FLP의 강성이 작은 경우에는 일정 길이 비 이상에서는 오히려 감소하였으나, 큰 경우에는 설치길이가 증가할수록 침하량 감소에 효과적이다. 이에 따른 박스구조물 높이(H = 250 mm)에 대한 최적 길이 비는 연성 1.38, 강성 0.73으로 산정되었다.

The settlement hardly occurs in structures supported by pile foundation such as abutment, culvert but a cavity is formed in the lower part of a structure. As a result, soil discharged from the lateral ground to the cavity accelerates the settlement of the lateral ground of the structure, resulting in a larger settlement. Therefore, in order to prevent problems caused by cavity under the structure supported by pile foundation, soil Flow Protector (briefly called 'FLP'), which can be easily installed on the side of structure, was developed. In this study, an laboratory model test was carried out to prove the reduction effect of settlement and to estimate the optimal installation length of the FLP. As a result, the installation of the FLP reduced the settlement of the lateral ground and prevented the leakage of lateral ground soil into the cavity. If the stiffness of the FLP is small, the state or active earth pressure is generated in the upper part, which is not favorable for stability. But if the stiffness of the FLP is high enough, the passive earth pressure area is generated in the upper part, which will be advantageous for the stability. Also, the increased installation length of FLP is effective to reduce the settlement. And the ratio of the optimal length of the FLP to the box structure height (H = 250 mm) are flexible FLP 1.38, stiff FLP 0.73.

키워드

참고문헌

  1. Bautista, F. E., Park, L. K., Im, J. C. and Lee, Y. N. (2006). "Variation of earth pressure acting on cut-and-cover tunnel lining with settlement of backfill." J. Korean Geotech Soc., Vol. 22, No. 6, pp. 27-40 (in Korean).
  2. Briaud, J. L., James, R. W. and Hoffman, S. B. (1997a). NCHRP Synthesis of highway practice 234: Settlement of bridge approaches (The bump at the end of the bridge), Transportation Research Board, National Research Council, Washington, D.C., p. 75.
  3. Briaud, J. L., Maher, S. F. and James, R. W. (1997b). "Bump at the End of the Bridge." J. Korean Soc. Civ. Eng., KSCE, Vol. 67, No. 5, pp. 68-69.
  4. Choi, C. Y., Kim, H. K. and Park, J. H. (2018). "Comparison of performance with backfill inclination slope and shape in railway abutment and transitional zone using centrifuge model tester." Journal of Korean Geosynthetics Society, Vol. 17, No. 1, pp. 85-93. https://doi.org/10.12814/JKGSS.2018.17.1.085
  5. Hearn, G. (1997). Synthesis on faulted pavement at bridge abutments, Report No. CDOTDTD-97-11, Colorado Department of Transportation, Denver, p. 218.
  6. Kim, T. H. (2017). A Study on the effect of differential movement reduction using Light-weighted Air-foam Soil Backfilling for Box culvert on the soft soil, Ph.D. Thesis, Pusan National University, p. 43 (in Korean).
  7. Ko, H. S., Im, J. C., Park, L. K. and Oh, M. L. (1996). "Model tests on the behaviour of sandy ground during tunneling." J. Korean Soc. Civ. Eng., KSCE, Vol. 1996, No. 2, pp. 371-374 (in Korean).
  8. Son, J. H., Im, J. C., Park, L. K. and Lee, T. H. (2003). "A study on the group effect of micropiles installed beneath shallow foundations." J. Korean Soc. Civ. Eng., KSCE, Vol. 2003, No. 10, pp. 3354-3357 (in Korean).
  9. Tatsuoka, F., Tateyama, M., Koseki, J. and Yonezawa, T. (2014). "Geosynthetic-reinforced soil structures for railways in Japan." Transportation Infrastructure Geotechnology, Vol. 1, Issue 1, pp. 3-53. https://doi.org/10.1007/s40515-013-0001-0
  10. White, D. J., Mekkawy, M. M., Sritharan, S. and Suleiman, M. T. (2007). " "Underlying" Causes for Settlement of Bridge Approach Pavement Systems." Journal of Performance of Constructed Facilities, ASCE, Vol. 21, No. 4, pp. 273-282. https://doi.org/10.1061/(ASCE)0887-3828(2007)21:4(273)
  11. Yoo, J. W., Im, J. C., Choi, M. B. and Park, D. H. (2018). "A numerical study on the settlement behavior of soft ground by installation of soil flow proctor." Proc. of the KSCE Conf., KSCE, pp. 632-633 (in Korean).