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2019 Vol.29, Issue 3 Preview Page

Research Article

Effect of CPR Foundation Reinforcement Assessed by Compressive Loading Tests

CPR 공법의 압축재하시험을 통한 기초지반의 보강효과

Seong-Seung Kang1
,
Jung-Han Kim2
,
Jeongdu Noh3
,
Chin-Surk Ko1*
강 성승1
,
김 정한2
,
노 정두3
,
고 진석1*
1Professor, Department of Energy and Resources Engineering, Chosun University
2CEO, Hyowon E&C Co., Ltd.
3Ph.D. Student, Department of Energy and Resources Engineering, Chosun University
1조선대학교 에너지자원공학과 교수
2효원이엔씨(주) 대표이사
3조선대학교 에너지자원공학과 박사과정
*Corresponding Author
30 September 2019. pp. 211-222
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Abstract

This study evaluates the yield load and allowable bearing capacity of ground in compressive loading tests to confirm the effect of CPR foundation reinforcement. The average compressive strength of the injection materials was higher than the planned compressive strength. Standard penetration tests for each stratum showed that foundation reinforcement improved the average N values, thereby increasing the bearing capacity of the ground. Compressive loading tests on two CPR piles revealed that the total and net settlement due to the maximum load exceed that permissible for the CPR pile diameter. The yield load and allowable bearing capacity calculated by the settlement criterion and the load-settlement curves varied greatly with the method applied. Therefore, it seems to be necessary to determine the optimum value through comprehensive analysis after applying various yield load calculation methods.

Keywords
CPR method
compressive loading
yield load
allowable bearing capacity
settlement

본 연구는 CPR 공법을 적용한 압축재하시험을 통하여 지반의 항복하중과 허용지지력을 평가하여 기초지반 보강효과를 확인하기 위한 것이다. 주입재의 평균압축강도는 계획된 강도보다 높게 나타났다. 또한 각 지층에서 표준관입시험 결과는 시험 전보다 시험 후의 평균 N값이 향상되었다. 즉, 이것은 지반의 지지력을 증대시키는 효과를 가져왔음을 의미한다. 두 종류의 CPR 말뚝 압축재하시험 결과에 의하면, 최대 재하하중에 의한 전침하량과 순침하량은 CPR 말뚝직경 허용범위를 초과하는 침하량을 나타냈다. 침하량 기준과 하중-침하량 곡선에 의해 산정한 항복하중 및 허용지지력은 적용되는 방법에 따라 값의 편차가 크게 나타났다. 따라서 허용지지력은 다양한 항복하중 산정법을 적용한 후 종합적인 분석을 통하여 최적의 값을 결정할 필요성이 있다고 사료된다.

키워드
CPR 공법
압축재하시험
항복하중
허용지지력
침하
References
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Information
  • Publisher :Korean Society of Engineering Geology
  • Publisher(Ko) :대한지질공학회
  • Journal Title :The Journal of Engineering Geology
  • Journal Title(Ko) :지질공학
  • Volume : 29
  • No :3
  • Pages :211-222
  • Received Date : 2019-07-31
  • Revised Date : 2019-08-27
  • Accepted Date : 2019-09-02
  • DOI :https://doi.org/10.9720/kseg.2019.3.211
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