• Journal of the Korean Geotechnical Society
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• v.27 no.2
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• pp.81-90
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• 2011

Domestic usage of high strength steel for pile has been limited to steel with yield strength (YS) of 490 MPa. However, design and construction cases abroad show beneficial usage of steel pipe with YS ranging in 500~700 MPa. In this study, YS 590 MPa steel pipe has been tested for driven pile foundation in Songdo area. Pile dynamic analysis (PDA) was carried out for 18 piles of which 16 piles have been reviewed for comparison of the PDA test results with those of GRLWeap analysis using SPT N value. Back analysis of PDA analysis was also carried out to narrow the deviation of standard SPT N value used in GRLWeap analysis. A regression equation is suggested for the shaft and toe resistance according to SPT N values for future GRLWeap analysis that can be used in the designing stage at Songdo area.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.105-111
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• 2013

The standard penetration test (SPT) has been widely used because of its usability, economy, and many correlations with soil properties among other factors. In SPT, hammer energy is an important factor to evaluate and calibrate N values. To measure hammer energy, an instrumented SPT rod was developed considering that stress waves transferring on rods during SPT driving are the same as stress waves transferring on piles due to pile driving. Using this idea, an instrumented SPT rod with a pile driving analyzer was applied as a pile capacity prediction tool in this study. In order to evaluate this method, SPT and dynamic cone tests with the instrumented SPT rod were conducted and also 2 pile load tests were performed on pre-bored steel pipe piles at the same test site. End bearings were predicted by CAPWAP analysis on force and velocity waves from dynamic cone penetration tests and SPT. Comparing these predicted end bearings with static pile load tests, a new prediction method of the end bearing capacity using the instrumented SPT rod was proposed.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.49-55
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• 2003

In this study, based on the relationship of the vertical force - settlement of batter piles obtained by pressure chamber model tests, the vertical bearing capacity of vertical and batter piles according to the increase of pile inclination was analyzed. A model open - ended steel pipe pile with the inclination of 5$^\circ$, 10$^\circ$ and 15$^\circ$ was driven into saturated fine sand with relative density of 50 %, and the static compression load tests were performed under each confining pressure of 35, 70 and 120 kPa in pressure chamber. The vertical bearing capacity of pile obtained from pressure chamber tests increased with the pile inclination. In the case of the inclination of 5$^\circ$, 10$^\circ$, 15$^\circ$, increasing ratios of pile bearing capacity were 111, 121, 127 ~ 140 % of vertical bearing capacity respectively. In the case of the inclination of above 20$^\circ$, the model tests could not be performed because of pile of pile head during compressive loading on the pile head.

• Journal of the Korean Geotechnical Society
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• v.32 no.5
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• pp.27-36
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• 2016

This paper presents the investigation of the major influence factors on the degree of soil plugging for open-ended piles based on the Coupled Eulerian-Lagrangian (CEL) numerical technique. The main objective of this study was to investigate the effect of soil plugging on the response of piles in various conditions. Through comparison of the results of field load tests, the CEL methodology was found to be in good agreement with the general trend observed by in situ measurement. Additionally, the parametric studies were performed by controlling the soil conditions, soil elastic moduli, end-bearing conditions and multi layers. It was found that the degree of soil plugging for sand layers was greater than that of clay layers. Also, the degree of soil plugging increased with an increase in both the soil stiffness and length of pile embedded in the bearing layer.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.130-137
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• 2017

Due to the economic growth and development of construction technology, a role of foundation to resist heavy loads has been increased. In this present study to improve the structural performance of reinforced concrete pile, the precast HPC pile reinforced with rebar and filling concrete was developed and the strength of pile was predicted based on the limit state design method. The safety of HPC pile strength was evaluated by comparing with the design values. The geometry of HPC pile is a decagon cross section with a maximum width of 500 mm and a minimum width of 475 mm, and the hollow head of pile thickness is 70 mm. The inner area of the hollow head part was made as the square ribbed shape presented in the limit state design code in order to achieve horizontal shear strength between pile concrete and filling concrete. From the shear test results, it was found that the stable shear strength were secured without abrupt failure until maximum load stage despite the shear cracks was found. Shear strength is 135% and 119% higher than that of design value calculated from limit state design code. The driving test results of HPC pile according to the presence of additional reinforcement showed the outstanding crack resistance against impact loads condition. From the bending test results the flexural load between PHC pile and HPC pile was 1.51 times and 1.48 times higher than that of the design flexural load of conventional PHC pile.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.244-247
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• 2002

The pile foundations have been chosen more frequently as the comprehensive development of the country progressed, especially where the ground conditions are not suitable for the construction and the dimension and the length of the piles utilized becomes larger and longer. The purpose of this study suggests the improvement method of construction management for PHC pile in an apartment house. To do This, We analyzed about current process and provided improved Process with IDEF method. And, The objectives of this research is to propose the means to solve the current problems and management factors from the results of the investigation.

• Ocean and Polar Research
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• v.25 no.spc3
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• pp.373-384
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• 2003

When pile foundation is constructed by dynamic method, it is desirable to perform monitoring of drivability with pile penetration. Dynamic pile monitoring yields information regarding driving hammer, cushion, pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. In this study, dynamic monitoring of the steel pipe pile was performed with Pile Driving Analyser (PDA). The PDA utilizes the wave propagation theory to compute numerous variables which describe the conditions of the hammer-pile-soil system in real-time and following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and estimation of pile bearing capacity. A series of PDA test were performed at the Ieodo Ocean Research Station (IORS) located in southeast of Marado, a southernmost small island south of Jeju Island. The drilling core sediments of Ieodo subsoil are composed of mud and sand, showing lamination and wavy or lenticular bedding, which were often bioturbated. This paper summarizes the results of PDA tests which were applied in measurement and estimation of large diameter open ended steel pipe pile driven by steam hammer, Vulcan-560 and MRBS-4600, at the marine sediments.

• Journal of the Korean GEO-environmental Society
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• v.9 no.1
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• pp.41-46
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• 2008

In this study, the analysis of load transition of PHC pile was performed with the static load test, which was driven in deep soft clay layer of MyungJi site in the western area of Pusan. The results of test showed that the range of unit side resistance of pile in sand layer were $7.4t/m^2$ to $23.3t/m^2$ and $6.4t/m^2$ in the soft clay layer, while the unit base resistance was $955t/m^2$ in dense silty sand layer. To select the most reasonable static bearing capacity formular, the field measured values are compared with the calculated ones from the suggested various formular. In the case of side resistance in sand layer, the suggest formular in the Structural Foundation Design Manual by KGS was most reasonable, while in clay layer Railroad Design Manual.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.73-80
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• 1999

Analytical studies on piles so far have been directed toward prediction of bearing capacity under vertical loads. Various static and dynamic formulas have been used in predicting the ultimate bearing capacity of a pile. Further, the reliability of these formulas has been verified by comparing the predicted values with the pile load test measurements. Accordingly, by means of the ultimate load from the data measured by the actual field load tests of PHC piles, safety factors were compared and analyzed static and dynamic formula methods applying to 4 different sites. As a result, the safety factor by Meyerhof formula method indicates 3.0 and the safety factor by Hiley formula method indicates 5.0.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.97-106
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• 2022

The domestic auger-drilled pile method generally manages the driving penetration (set) value with the final stage of construction. The penetration value has been estimated by manual measurement for a long time. The automation technology is yet to be applied due to workability and high-cost limitations, despite safety issues and lack of reliability in measured results. In this study, a non-contact pile penetration measurement device was developed. Further, the field performance was verified by comparing the measurements with a conventional automation device. In addition, the on-site field quality control method was analyzed using the penetration measuring device. The field experiments confirmed that more reliable bearing capacity estimation could calculate the dynamic damping coefficient and the modified Hiley formula with the developed device. Furthermore, it can be used for pile construction management from the bearing capacity viewpoint, even for piles not subjected to dynamic load tests.