Calculation of Base Load Capacity of Bored Pre-cast Piles Using New PHC PIles with Steel Pipe at Pile Toe

Kyu-Ho Paik

doi:10.7843/kgs.2016.32.9.5

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2016 Vol.32, Issue 9 Next Page

Calculation of Base Load Capacity of Bored Pre-cast Piles Using New PHC PIles with Steel Pipe at Pile Toe 강관 부착 PHC파일로 시공된 매입말뚝의 선단지지력 산정

30 September 2016. pp. 5-16

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Abstract

New PHC piles, where short steel pipes are attached to the pile toe, are developed to increase the base load capacity of bored pre-cast piles embedded in weathered rock. In this study, new bored pre-cast piles using the new PHC piles are installed at 7 test sites with different soil conditions, and static and dynamic pile load tests are performed to investigate quantitative characteristics on the base load capacity of new bored pre-cast piles. In addition, based on the static pile load test results, a new empirical equation for estimating the base load capacity of new bored pre-cast piles is proposed. A comparison between predicted and measured base load capacities shows that the proposed empirical equation produces conservative predictions for the new bored pre-cast piles. However, the existing design criterion significantly underestimates the base load capacity of new bored pre-cast piles.

Keywords

Base load capacity

Bored pre-cast pile

Empirical equation

Full-scale pile load test

New PHC pile

풍화암에 근입된 매입말뚝의 선단지지력을 증대시키기 위해 파일 선단에 짧은 길이의 강관을 부착한 새로운 PHC파일이 개발되었다. 본 연구에서는 새로운 PHC파일로 시공된 매입말뚝의 선단지지력 특성을 정량적으로 파악하기 위하여 지반조건이 다른 7개 현장에 새로 개발된 매입말뚝을 시공하고 정재하 및 동재하시험을 수행하였다. 그리고 정재하시험에서 얻어진 결과에 근거해서 새로운 PHC파일로 시공된 매입말뚝의 선단지지력을 산정하기 위한 경험식을 제안하였다. 현장에서 측정된 선단지지력과 지지력 산정식으로부터 계산된 선단지지력을 비교한 결과 기존 지지력 산정식은 새로운 PHC파일로 시공된 매입말뚝의 선단지지력을 상당히 과소평가하는 반면 제안된 경험식은 새로운 PHC파일로 시공된 매입말뚝의 선단지지력을 안전측에서 산정하는 것으로 나타났다.

References

1.Carranza-Torres, C. and Fairhurst, C. (1999), “The Elasto-Plastic Response of Underground Excavations in Rock Masses that Satisfy the Hoek-Brown Failure Criterion”, International Journal of Rock Mechanics and Mining Sciences, Vol.36, pp.777-809.

2.CEN (Comité Européen De Normalisation) (2004), EN 1997 Eurocode 7, Geotechnical-Part 1: General Rules, CEN.

3.Davisson, M. T. (1972), “High Capacity Piles”, Proceedings of Lecture Series on Innovations in Foundation Construction, ASCE, Illinois Section, Chicago, pp.81-112.

4.Jardine, F. M. (1988), “Introduction to Papers 1-9”, Proceedings of Penetration Testing in the UK, ICE, Birmingham, pp.23-49.

5.KGS (Korean Geotechnical Society) (2009), Foundation Design Manual for Structure.

6.Paik, K. H. and Salgado, R. (2003), “Determination of Bearing Capacity of Open-Ended Piles in Sand”, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.129, No.1, pp.46-57.

7.Paik, K. H. and Yang, H. J. (2013), “Development of Steel Pipe Attached PHC Piles for Increasing Base Load Capacity of Bored Pre-cast Piles”, Journal of Korean Geotechnical Society, Vol.29, No.8, pp.53-63.

Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 32
No :9
Pages :5-16
Received Date : 2016-05-04
Revised Date : 2016-08-18
Accepted Date : 2016-08-25
DOI :https://doi.org/10.7843/kgs.2016.32.9.5

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

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