Comparison of Splices between Bolts and Welding Spliced PHC Piles

Myunghak Kim; Yongkyu Choi

doi:10.7843/kgs.2018.34.12.93

All Issue

2018 Vol.34, Issue 12 Preview Page Next Page

Research Article

Comparison of Splices between Bolts and Welding Spliced PHC Piles 볼트 수직이음 PHC말뚝와 용접이음 PHC말뚝의 이음부 거동 비교

31 December 2018. pp. 93-103

PDF XML

Abstract

Behaviors of splices between bolts and welding spliced PHC piles using the tensile strength test were analyzed. The bolts spliced PHC piles, which were tightened over 200 N･m tightening torque, showed straight V shaped line at splices at the lowest 20 N load. Both sides of PHC piles stayed straight, so the full section of bolts spliced piles did not show the unifying behavior, which was the most important performance requirement as pile. Other bolts spliced PHC piles, tightened with 20 N･m loosening torque, also showed the same straight V shaped line at splices for each step of loading. The full section of bolts spliced piles did not return to the initial position after each step of unloading and did not show the elastic material behavior. The splices quality of bolts spliced piles is much lower than that of welding spliced piles with respect to displacement of splices during each step of loadings, residual displacements during each step of unloadings, and failure loads. Results showed that bolts spliced PHC piles, tightened with both over 200 N･m and as low as 20 N･m torque, fell short of performance requirements of spliced PHC pile.

Keywords

Bolts spliced PHC piles

welding spliced PHC piles

straight V shape line

unifying behavior

elastic material behavior

splices quality

볼트 수직이음 PHC말뚝 및 용접이음 PHC말뚝에 대한 휨강도시험을 실시하여 각 이음 PHC말뚝의 성능을 비교 분석하였다. 200N･m이상의 토크치로 체결한 볼트 수직이음 PHC말뚝에서는 가장 낮은 하중단계인 20kN에서도 볼트 수직이음구에서 좌우로 꺾인 변형 양상(직선 v형 라인)이 나타났으며 PHC말뚝 본체는 완전한 직선 형태를 유지하고 있었으므로 볼트 수직이음 PHC말뚝은 말뚝의 가장 중요한 성능인 일체화 거동을 하지 않았다. 체결토크가 풀린 즉, 20N･m의 토크치로 체결한 볼트 수직이음 PHC말뚝은 각 하중 단계에서 이음부위에 대하여 양쪽으로 대칭된 직선 V형 상태의 변위 양상을 나타내고 있었다. 각 하중 단계에서 하중 제거 시 이음말뚝은 하중 재하 전의 상태로 돌아가지 않았으므로 탄성 재료 거동을 나타내지도 않았다. 재하단계에 따른 이음부 변위 및 재하 하중 제거 후의 잔류 변위, 이음 PHC말뚝의 파괴하중 및 3가지 기본 성능 등을 비교한 결과 볼트 수직이음 PHC말뚝의 이음 품질은 용접이음 PHC말뚝의 이음 품질에 크게 미달하였다. 따라서 200N･m 이상의 토크치로 체결한 볼트 수직이음 PHC말뚝이나 체결토크가 풀린 볼트 수직이음 PHC말뚝은 이음말뚝의 기본 성능에 크게 미달하는 것으로 나타났다.

References

For-u Engineering Corp. (2015), Specification "Ez Pile Connector", pp.1-11. (In Korean)

Kim, M. H. (2018a), Safe installation method developement project for extension plate attached PHC piles and bolt spliced PHC piles(Final report), Inje University industry academic cooperation foundation, pp.1-341. (In Korean)

Kim, M. H. (2018b), Safe installation method deveropement project for extension plate attached PHC piles and bolt spliced PHC piles (Final report) - supplement, Inje University industry academic cooperation foundation, pp.A-1-1~A-13-48. (In Korean)

Kim, B. C., Song, C. Y., Kwon, H. S., and Lim, H. S. (2006), A Bolting Method for Connecting PHC Piles, KSCE 2006 Convention Conference & Civil expo, pp.4410-4413. (In Korean)

Korea Construction Standards Center (2016a), KDS 24 14 50 Design standard of bridge substruction (General design method) 4.6.5, pp.1-47. (In Korean)

Korea Construction Standards Center (2016b), KCS 11 50 15 Precast pile, pp.1-13. (In Korean)

Korea Construction Standards Center (2017), KRCCS 67 56 15 Driven Pile foundation Construction, pp.1-14. (In Korean)

Korea Expressway Corporation (2018), EXCS 11 50 15 Precast pile, pp.1-15. (In Korean)

Korea Land & Housing Corp. (2017), LH Special specification 23021 Precast pile foundation (The Driven Pile), pp.1-13. (In Korean)

Korea rail network authority (2013), Korea Rail guide spec (Road bed), pp.5-6~5-19. (In Korean)

Korea Standards Association (2002), KS F 7001 Standard practice for construction of spun concrete piles, pp.1-45. (In Korean)

Korea Standards Association (2003), KS F 4306 Pretensioned spun high strength concrete piles, pp.1-51. (In Korean)

Ministry of oceans and fisheries (2016), Special specification 8. Foundation pile, pp.8-399~8-471. (In Korean)

Paik, K. H., Lee, J. H., and Park, Y. B. (2005), Development of New Joining Method for PHC Piles, KGS Spring Conference, Vol. 2005, pp.81-88. (In Korean)

Seoul Metropolitan City (2018), Seoul guide spec. (Civil part), pp. 5-9~5-25. (In Korean)

Smartec Engineering Corp. (2016), Specification "PHC pile bolt vertical joint", pp.1-3. (In Korean)

Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 34
No :12
Pages :93-103
Received Date : 2018-11-15
Revised Date : 2018-12-07
Accepted Date : 2018-12-09
DOI :https://doi.org/10.7843/kgs.2018.34.12.93

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

All Issue