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2019 Vol.35, Issue 11 Preview Page

Research Article

Ultimate Capacity of Guardrail Supporting Pile Subjected to Lateral Impact Load Using Centrifuge Model Test

원심모형실험을 통한 차량방호울타리 지지말뚝의 수평방향 충격하중에 대한 극한지지력

Jong Seok Yun1
,
Min Jy Lee2
,
Yun Wook Choo3*
윤 종석1
,
이 민지2
,
추 연욱3*
1Member, Graduate Student, Dept. of Civil Environmental Engrg., Kongju National Univ.
2Member, Graduate Student, Dept. of Civil Environmental Engrg., Kongju National Univ.
3Member, Prof., Dept. of Civil Environmental Engrg., Kongju National Univ.
1정회원, 공주대학교 건설환경공학과 박사과정
2정회원, 공주대학교 건설환경공학과 석사과정
3정회원, 공주대학교 건설환경공학부 교수
* Corresponding Author
30 November 2019. pp. 25-36
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Abstract

차량이 도로를 이탈하여 성토부로 추락하는 것을 방지하기 위해 설치되는　연성　차량방호울타리는 사면부 시작점 근처에 도로방향으로 일렬로 근입된 무리말뚝과 무리말뚝 위에 부착되는 가드레일로 구성되어 있다. 차량방호울타리에 차량 충돌 시, 충돌에너지의 일부는 가드레일의 변형에 의해 흡수되며, 나머지 에너지는 가드레일을 지지하는 말뚝과 지반의 상호작용으로 저항하게 된다. 본 논문에서는 충격하중에 대한 말뚝과 지반의 상호작용을 원심모형실험을 수행하여 분석하였다. 풍화토로 다져진 경사지반에 설치된 단말뚝의 충격하중에 대한 극한지지력 및 거동특성을 분석하고자 하였다. 이를 위해 말뚝에 충격하중을 모사할 수 있는 하중재하시스템을 설계 및 구축하였다. 구축된　원심모형실험체 및 하중재하시스템을 이용하여 하중 및 지반조건에 대한 매개변수연구를 수행하였다. 최종적으로, 말뚝의 하중재하점에서 나타나는 하중-변위 곡선을 계측하여 충격극한지지력을 분석하였다. 또한, 휨모멘트 분포도로부터 산정된 지반반력 분포도를 도출하였고, 선행 연구결과와 비교하여 차량 방호울타리 지지말뚝의 지지거동을 분석하였다.

The safety barrier is installed on road embankment to prevent vehicles from falling into road side slope. Among the safety barrier, flexible guardrails are usually installed. The flexible guardrail generally consists of a protection cross-beam and supporting in-line piles. These guardrail piles are installed nearby slope edge of road embankment because the side area of the road is much narrow. The protection cross-beam absorbs impact energy caused by vehicle collision. The pile-soil interaction also absorbs the rest of the impact energy and then, finally, the flexible guardrail system resists the impact load. This paper aims to investigate the pile-soil interaction subjected to impact load using centrifuge model tests. In this study, a single pile was installed in compacted residual soil and loaded under lateral impact load. An impact loading system was designed and developed available on centrifuge tests. Using this loading system, a parametric study was performed and the parameters include types of loading and ground. Finally, the ultimate bearing capacity of supporting pile under impact load was analyzed using load-displacement curve and soil reaction pressure distributions at ultimate were evaluated and compared with previous studies.

Keywords
Centrifuge model test
Guardrail
Lateral impact load
Supporting pile
Vehicle Collision

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Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 35
  • No :11
  • Pages :25-36
  • Received Date : 2019-08-14
  • Revised Date : 2019-10-10
  • Accepted Date : 2019-10-27
  • DOI :https://doi.org/10.7843/kgs.2019.35.11.25
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