Verification of Bearing Capacity Enhancement Effect by Protrusions Along the Shaft of Cast-in-place Piles Using Three-Dimensional Numerical Analysis

Seokjung Kim; Soon-Yong Jeong; Hyun-Sik Jin; Jin-Tae Han

doi:10.7843/kgs.2024.40.6.87

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2024 Vol.40, Issue 6 Preview Page Next Page

Verification of Bearing Capacity Enhancement Effect by Protrusions Along the Shaft of Cast-in-place Piles Using Three-Dimensional Numerical Analysis 3차원 수치해석을 통한 현장타설말뚝 주면부 돌기 형성에 의한 지지력 증대효과 검증

31 December 2024. pp. 87-100

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Abstract

The shaft resistance of cast-in-place (CIP) piles is affected by the roughness of the pile surface and the pile-ground interface. Thus, various studies have investigated increasing the bearing capacity of piles in consideration of the protrusions and roughness of the pile shaft. However, due to the limitations of field applications, few studies have considered the development and effect of artificially forming protrusions on the main surface of the piles. Therefore, in this study, we developed equipment to form protrusions along the pile shaft and verified the effect of the protrusions on increasing the bearing capacity using three-dimensional numerical analyses. The results confirmed that the allowable bearing capacity of the CIP piles increased by approximately 38%-58% with the protrusion effect, and most of the increased bearing capacity corresponds to the increased shaft resistance by the protrusion. These results analytically prove that the formation of the protrusion along the pile shaft is very effective in terms of increasing the bearing capacity of CIP piles.

Keywords

Bearing capacity

Cast-in-place pile

Enhancement

Numerical analysis

Protrusion along the shaft

현장타설말뚝의 주면마찰력은 말뚝-지반 사이 굴착면 또는 말뚝 표면의 거칠기의 영향에 따라 결정된다. 이에, 공벽의 돌기 및 거칠기를 고려한 말뚝의 지지력 증대에 대한 연구가 지속적으로 진행되어 왔으나, 현장 적용의 한계 등으로 인해 말뚝의 주면에 돌기를 인공적으로 형성하는 공법 개발과 그 효과에 대한 연구는 제한적으로 이루어져왔다. 본 연구에서는 현장타설말뚝의 지지층인 암반 근입부에 돌기를 형성하는 장비를 개발하고, 형성된 돌기의 형태를 바탕으로 3차원 수치해석을 통해 돌기 형성에 의한 지지력 증대효과를 검증하였다. 그 결과, 돌기 형성 효과로 인해 현장타설말뚝의 허용 지지력이 약 38~58% 증가하는 것을 확인하였으며, 지지력 증가분의 대부분이 주면마찰력의 증가분임을 확인하였다. 이를 통해, 현장타설말뚝의 지지력 증가를 위해, 주면부 돌기 형성이 매우 효과적임을 해석적으로 증명하였다.

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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 : 40
No :6
Pages :87-100
Received Date : 2024-11-25
Revised Date : 2024-12-02
Accepted Date : 2024-12-02
DOI :https://doi.org/10.7843/kgs.2024.40.6.87

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

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