• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1140-1147
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• 2010

To find the soil plug of steel piles shaped by jet grouting, 4 blocks of cement milk with cube of 1.2m were made. 4 open-ended steel piles on the blocks were rested. The inner end part of 2 the piles was not reinforced. Cement milk 65%(SIG-1) and 100%(RJP-1) were filled into the block and height of 4.2 times of inner the pile diameter respectively. And the other the piles were welded 2 steel ring. The filling of the cement milk was an equal method as before(SIG-2 and RJP-2). Also the strain gauges were installed and the static pile load tests were done at the piles all. As a result, list in great order for effect of soil plug was (1)SIG-1, (2)SIG-2, (3)RJP-1, (4)RJP-2. This is because of strength and filling height of cement milk. And the higher the strength is, the greater the confining coefficient is.

• Journal of the Korean Geosynthetics Society
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• v.22 no.1
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• pp.39-51
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• 2023

The bearing capacity of the prebored pile has been studied by many researchers. However, The bearing capacity of the prebored pile has been studied by many researchers. However, comparative studies between design data and pile load test data on the load sharing ratio and the settlement were insignificant. Therefore, the design data and the static load test results were compared for the prebored open-end steel piles. In the compressive static pile load test, the load sharing ratios of the base resistance and the shaft resistance were 13%~40% and 60%~87%, respectively and the settlements were measured 2.2mm~4.7mm. In the current bearing capacity calculation formula, the base resistance was shared between 54% and 75%, and the shaft resistance was shared between 25% and 46% and the settlements were calculated about 19.8mm~23.6mm. The settlement in the current bearing capacity calculation formula was 321% to 776% (average : 445%) larger than the settlement in the result of load test. When the settlement were calculated using the load sharing ratio in the pile load tests, it was 137% to 525% larger than the test settlement, and it was as large as 204% on average. It was confirmed that an appropriate evaluation of the load sharing ratio had an important effect on the calculation of pile settlement.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.21-33
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• 2017

This paper presents the analysis of plugging effect especially when the large diameter steel pipe pile was installed by considering driveability (BPM, blow per meter). The Coupled Eulerian-Lagrangian (CEL) technique was used to simulate the driving of open-ended piles into soil. To consider the driveability, the applied driving energy for each pile was obtained from the analysis results by using the wave equation. The parametric studies were performed for different pile diameters, penetration depths of pile, soil elastic modulus and BPM. It was found that the SPI is almost constant with increasing both the pile diameter and the required driving energy. It is also found that the plugging effect increases with increasing the pile length, resulting in the increase of lateral earth pressure. Based on this study the apparent magnitude and distribution of the lateral earth pressure is proposed for inside portion mobilizing soil plug.

• Journal of the Korean Geotechnical Society
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• v.31 no.8
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• pp.29-38
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• 2015

This paper presents the application of the Coupled Eulerian-Lagrangian (CEL) numerical technique to simulate the driving of open-ended piles into sandy soil. The main objective of this study was to investigate the applicability of CEL technique to the behavior of the driven pile penetration. Comprehensive studies to verify the behavior of driven pile penetration are presented in this paper. Through comparison with results of field load tests, the CEL methodology was found to be in good agreement with the general trend observed by in situ measurement, and the CEL approach accurately simulated the behavior of driven pipe piles.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.141-148
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• 2000

For the construction of 4.8km long Multi-Purpose Jamuna Bridge in Bangladesh, 2 or 3 large diameter open-ended steel pipe piles were used for the foundation of piers. A total of 123 piles were driven for 50 piers and 2 test piles from the river bed through the normally-consolidated upper sand layer and rested n top of gravel layer. Two types of piles, having 3.15 or 2.50m diameter and variable wall thickness in the range of 40 to 60mm, were driven to the depths of 69 to 74m with the rake of 6:1 by connecting 2 or 3 pieces of short piles. Dynamic pile tests were performed on 24 selected piles during pile driving and soil plug length inside the pile was also measured after driving of each short section.These piles were plugged with soil to, though slightly affected by pile diameters, about 75% of total length of pile driven. Active plug at the tip of pile contributed substantial amount of inner skin friction to the total capacity. Piles soon after driving showed a skin-friction dominant pile behaviour, tat is, 90% of total capacity being developed by skin resistance. Quakes values and Smith damping factors were almost constant regardless of pile diameters. This result reflects the influence of uniform soil condition at the site.

• Journal of the Korean Geotechnical Society
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• v.29 no.10
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• pp.39-48
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• 2013

This paper presents an equation to depict the penetration behavior during the standard penetration test (SPT) in sandy deposits. An energy balance approach is considered and the driving mechanism of the SPT sampler is conceptually modeled as that of a miniature open-ended steel pipe pile into sands. The equation consists of three sets of input parameters including hyperbolic parameters (m and ${\lambda}$) which are difficult to determine. An iterative technique is thus applied to determine the optimized values of m and ${\lambda}$ using three measured values from a routine SPT data. It is verified from a well-documented record that the simulated penetration curves are in good agreement with the measured ones. At a given depth, the increase in m results in the decrease in ${\lambda}$ and the increase in the curvature of the penetration curve as well as the simulated N-value. Generally, the predicted penetration curve becomes nearly straight for the portion of exceeding the seating drive zone, which is more pronounced as soil density increases. Thus, the simulation method can be applied to extrapolating a prematurely completed test data, i.e., to determining the N value equivalent to a 30 cm penetration. A simple linear equation is considered for obtaining similar results.