• Proceedings of the Korean Geotechical Society Conference
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• 2002.06a
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• pp.43-56
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• 2002

To find a lateral long term behavior of driven H-piles in embankment, inclinometer is installed at pile and measurement is done during a year. When behavior of measured slope angles is in accord with behavior of nonlinear p-y curves(Reese, Murchison and O'Neil, Matlock's p-y analysis), maximum displacement of pile head, maximum stress and maximum bending moment of pile obtained from the numerical analysis are shown. As results, maximum lateral displacement at pile head, maximum stress and maximum bending moment of pile are shown linear behavior, And maximum lateral load, maximum lateral displacement, and maximum bending moment at pile obtained from the numerical analysis are 8∼12.4tonf, 9∼10.1㎜, and 10.39∼12.67tonf-m per pile according to the curves, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.173-182
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• 2000

To find axial and lateral responses of impact-driven H piles in embankment(SM), the H piles are instrumented with electric strain gages, dynamic load test is performed during driving, and then the damage of strain gages is checked simultaneously. Axially and laterally static load tests are performed on the same piles after one to nine days as well. Then load-settlement behavior is measured. Furthermore, to find the set-up effect in H pile, No. 4, 16, 26, and R6 piles are restriked about 1, 2, and 14 days after driving. As results, ram height and pile capacity obtained from impact driving control method become 80cm and 210.3∼242.3ton, respectively. At 15 days after driving, allowable bearing capacity by CAPWAP analysis, which 2.5 of the factor of safety is applied for ultimate bearing capacity, increases 10.8%. Ultimate bearing capacity obtained from axially static load test is 306∼338ton. This capacity is 68.5∼75.7% at yield force of pile material and is 4∼4.5 times of design load. Allowable bearing capacity using 2 of the factor of safety is 153∼169ton. Initial stiffness response of the pile is 27.5ton/mm. As the lateral load increases, the horizontal load-settlement behaves linearly to which the lateral load reaches up to 17ton. This reason is filled with sand in the cavity formed between flange and web during pile driving. As the result of reading with electric strain gages, flange material of pile is yielded at 19ton in horizontal load. Thus allowable load of this pile material is 9.5ton when the factor of safety is 2.0. Allowable lateral displacement of this pile corresponding to this load is 23∼36mm in embankment.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.195-202
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• 1998

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.575-582
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• 2002

To find a lateral long term behavior of driven H-piles in embankment, inclinometer is installed at pile and measurement is done during a year. When behavior of measured slope angles is in accord with behavior of nonlinear p-y curves(Reese, Murchison and O'Neil, Matlock's p-y analysis), maximum displacement of pile head, maximum stresses and maximum bending of pile obtained from the numerical analysis are shown. As results, maximum lateral displacement at pile head, maximum stress and maximum bending moment of pile are shown linear behavior. And maximum lateral load, maximum lateral displacement, and maximum bending moment at pile head obtained from the numerical analysis are 8∼12.4tonf, 9∼10.1mm, and 10.39∼12.67tonf-m per pile according to the curves, respectively.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.95-100
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• 2004

H-pile can be more easily driven than pipe pile by pile driver and shows high skin friction and plugging effect. And lately It is well grown that the high strength H-pile has been widely used f3r pile foundations. To compare the skin frictions of H piles under different density soil conditions, this paper presents results of a series of model tests on vertically loaded group piles. Model piles made of steel embedded in weathered granite soil were used in this study. Pile arrangements $(2\times2,\;3\tunes3)$, pile space(2D, 4D, 6D), and soil density$(D_r=40\%,\;80\%)$ were tested. The main results obtained from the model tests can be summarized as follows. The series of tests found that compression load for group piles increases as number of piles increase and piles space ratic decrease to $D_r=40\%$ of soil density. The analysis also found that the theoretical value of skin friction for group piles is greater than practical value as piles space ratio increases to $D_r=40\%$ of soil density. Piles showed the greatest difference of the skin friction in case that the pile space ratio(S/D) is 6. The theoretical value by Meyerhof and DM-7 showed 1.83 times and 1.32 times respectively as great as practical value in case of S/D=6 and $2\times2$.

• Journal of the Korean Geotechnical Society
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• v.22 no.10
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• pp.47-54
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• 2006

H-pile can be more easily driven than pipe pile by pile driver and shows high skin friction and plugging effect. This experimental study was devoted to investigate skin friction of H group piles in granite soil under laboratory test. Pile arrangements $(1{\times}2,\;1{\times}3,\;2{\times}2,\;2{\times}3,\;3{\times}3)$, pile space (2D,4D,6D), and soil density $(D_r=40%,\;80%)$ were tested. The main results obtained from the model tests can be summarized as follows. Distribution ratio of skin friction for total load decreased by $48{\sim}39%$ (dense soil), $32{sim}27%$ (loose soil) as piles space ratio increases in case of $3{\times}3$ group piles. And the distribution ratio of skin friction by pile settlements under loose soil decreased by about $58{\sim}33.2%$ in $2{\times}2$ group piles and about $65{\sim}38%$ in $3{\times}3$ group piles respectively.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.29-44
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• 1999

This paper shows the results of model tests on the lateral behavior of single rigid pile, which was constructed by driving, in homogeneous and non-homogeneous (two layered) NakDong River sands. The purpose of the present paper is to investigate the effect of ratio of lower layer thickness to embedded pile length, relative density of sand and pile construction conditions (Driven & Embedded piles) on the characteristics of lateral behavior of single pile. These effects can be quantified only by the results of model tests. As a model result, the lateral behavior depends upon the pile construction condition in loose-density soil more than in high-density soil. If the pile construction depends upon driving construction, the decrease of deflection remarkably increases for both loose homogeneous sand and non-homogeneous soil$(E_{h1}/E_{h2}/=0.18)$ with high thickness of upper layer but the decrease of maximum bending moment shows the opposite result to the decrease of deflection. And, with respect to deflection, it was found that the deflection ratio $(y_{Driven}y_{Embedded})$ of embedded to driven piles has the ranges of 0.65 - 0.88 $(D_r=90%)$0.38 - 0.65 $(D_r=61.8%)$ for each relative density of homogeneous soil and the range of 0.6 - 0.88 for non-homogeneous soil. Also, in this study, the experimental equation for the effects of drop height (DH) and H/L on the ratios of $y_D/y_E\; and MBM_D/MBM_ E$ is suggested from model tests.

• Journal of the Korean Geotechnical Society
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• v.25 no.1
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• pp.41-54
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• 2009

The purpose of this research is to introduce the new temporary earth retaining wall system using landslide stabilizing piles. This system is a self-supported retaining wall (SSR) without installing supports such as tiebacks, struts and rakers. The SSR is a kind of gravity structures consisting of twin parallel lines of piles driven below excavation level, tied together at head of soldier piles and landslide stabilizing piles by beams. In order to investigate applicability and safety of this system, a series of experimental model tests were carried out and the obtained results are presented and discussed. Furthermore, the measured data from seven different sites on which the SSR was used for excavation were collected and analyzed to investigate the characteristic behavior lateral wall movements associated with urban excavations in Korea. It is observed that lateral wall movements obtained from the experimental model is in good agreement with the general trend observed by in site measurements.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.167-185
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• 1999

A series of model tests was performed to find the characteristics of lateral behavior of single rigid pile. This paper shows the results of model tests on the lateral behavior of single rigid driven pile in non-homogeneous(two layered) Nak-Dong River sands. The purpose of this paper is to investigate the effect of the ratio of lower layer thickness to embedded pile length, the coefficient ratio of the subgrade reaction and the pile construction conditions(driven & embedded piles) on the characteristics of lateral behavior of single pile. The results of model tests show that the lateral behavior in non-homogeneous soil depends upon drop energy considerably, that is, in the case of H/L=0.75, as the drop energy increases three times the decrease percentage increases about 2.12 times. In the driven pile with non-homogeneous soil of $E_{h1}/E_{h2}=5.56$, the effect of upper layer with large stiffness on the decrease of lateral deflection is remarkably smaller than embedded pile. In non-homogeneous soil, the maximum bending moment of driven pile is in the range of 100 132% in comparison with embedded pile. The reason is that the stiffness of soil around pile increases with drop vibration and so the pile behavior is similar to the flexible pile behavior by means of the increase of relative stiffness of pile, In this paper, the experimental equations for lateral load and H/L on $y_D/y_E \; & \; MBM_D/MBM_E$ are suggested from model tests.

• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.19-26
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• 2003

Recently, for the design of pile foundations on the soft ground condition, it is recognized that set-up effects are another important factor which influence the characteristics of bearing capacity of pile. In this paper, the thirteen dynamic pile loading tests were performed at the two different construction sites and the end of initial driving(EOID) were also performed and then restrike tests were performed after certain time lag. The H-pile, pipe pile, PHC pile are installed by driving into the loose silty soil and then restrike tests were performed. Nine days after pile driving, the bearing capacity of H and pipe pile were increased whereas there is not bearing capacity increasement with PHC pile. When the dense silty soil, the restrike test results showed that the bearing capacity of H and pipe pile increased up to 1.17 times. The 1-st and 2-nd restrike tests performed after 6 and 12 day, respectively. The results showed that the bearing capacity of PHC pile was decreased but the bearing capacity of piles were increased up to 1.38 times after 13 days with the third restrike test.