Analysis of the Bearing Capacity of Helical Pile with Hexagonal Joints.

Daehyeon Kim,Kyungho Park,Kyemoon Baek

doi:10.3390/ma11101890

Abstract

This study aims to improve shafts with hexagonal joints so that they will not require welding or bolts in static load tests. In order to evaluate the bearing capacity of helical piles, two sites were selected to conduct pile installation for the field test and the pile load test. For the pile load test, a static pile load test and a dynamic pile load test were carried out, and torque was measured during pile installation in a field test to compare and analyze the expected bearing capacity and thus assess the feasibility of the method for estimating the bearing capacity. The field pile load test revealed that the bearing capacity of the gravity grout pile was the same or greater than 600 kN in the static pile load test in accordance with the AC 358 code. The non-grout pile showed a bearing capacity that was the same or smaller than 600 kN, suggesting that gravity grouting is required. Moreover, the field pile load test was used to establish the bearing capacity equation considering the torque in the pile installation, and a small number of samples were used to establish the equation, which can be used as basic data.

Highlights

A helical pile is a non-displacement pile foundation that implements bearing capacity by attaching at least one helix plate to a hollow shaft to be rotary-penetrated into the ground
Each country has its own standard for the safety factors applied to evaluating the allowable bearing capacity using the static load test, and different standards should be applied depending on the pile types and installation methods
The following conclusions were drawn by analyzing the static load test results from the field test, dynamic pile load test, and comparing the bearing capacity estimated with the measured torque for Korean ground

Summary

Introduction

A helical pile is a non-displacement pile foundation that implements bearing capacity by attaching at least one helix plate to a hollow shaft to be rotary-penetrated into the ground. The helical pile can be installed with low-noise and low-vibration performance by means of a torque machine that guides rotary penetration to a target depth. This is a pile that can be installed with a comparatively small machine and in locations with limited installation spaces, for example, commercial buildings or historic sites.

Objectives

Methods

Results

Conclusion