• Journal of the Korean Geotechnical Society
• /
• v.22 no.10
• /
• pp.47-54
• /
• 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 Geosynthetics Society
• /
• v.22 no.1
• /
• pp.75-85
• /
• 2023

In areas where excavation works are carried out, it is very important to select a retaining wall method to minimize ground water level and ground subsidence changes. In this regard, the use of Secant Pile Wall(SPW) method, which can complement the disadvantages of the CIP method, is gradually domestic increasing for the construction of retaining wall method. This study investigated the design elements of the SPW method and the interrelationship between the structural stability factors of the wall. The design elements for the retaining method are the overlap length between piles, pile diameter, and the specifications of the H-Beam specifications, while the structural stability factors of the wall are the bending stress, shear stress, horizontal displacement, and concrete strength. The study results showed that the pile diameter and H-Beam specifications have a significant impact on the capacity of the H-Beam, the overlap length and pile diameter have a significant impact on the horizontal displacement, and the pile diameter and H-Beam specifications have a significant impact on the required strength of the concrete.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.11
• /
• pp.39-51
• /
• 2009

This is a study on rectangular-shaped passive row piles in inclined sand-ground by model tests. The experiment controlled the angle of inclination of ground and induced the ground destruction. We also measured the behavior of row piles, by adjusting the shape, position and spacing of piles. As a result, we confirmed the earth pressure, the lateral resistance, and the effect of depressing on the ground variation working on passive pile. The effect of B-type pile of which the front width is wide is bigger than that of H-type pile of which the side width is wide. We can find out the failure angle of slope, the shared force of pile and soil by using the lateral resistance graph based on slope angle.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.3
• /
• pp.17-22
• /
• 2010

This paper analyzed the characteristics of p-multiplier and the load distribution of H-pile group installed in weathered soil under horizontal loading. The results of this study conducted in pile arrangement ($2{\times}3$, $3{\times}3$), the pile center to center spacing (2D, 4D, 6D), and soil density (relative density: 40%, 80%) were drawn as follows. As to the average horizontal loading applied to each pile in pile groups, the fewer number of piles was, the larger average horizontal resistance became. As the result of analysis on p-y curves of single piles and pile groups according to the pile distance and the soil density, as the pile spacing was increased from 2D to 6D, the interaction coefficients of pile group showed 0.85~0.94 (piles in the front row), 0.57~0.79 (piles in the middle row), and 0.60~0.71 (piles in the rear row) in the loose ground and showed 0.76~0.82 (piles in the front row), 0.58~0.73 (piles in the middle row), and 0.53~0.70 (piles in the rear row) in the dense ground. As above, the wider pile distance was, the larger interaction coefficient value was shown among piles. In addition, piles in the front row showed bigger interaction coefficients than that of piles in the middle and back row.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.5
• /
• pp.65-80
• /
• 1999

This paper shows the results of a series of model tests on the behavior of single flexible pile, which is subjected to lateral load, in non-homogeneous Nak-Dong River sands, consisting of two layers. The purpose of the present paper is to investigate the effects of ratio of lower layer thickness to embedded pile length, ratio of soil modulus of upper layer to lower one, and pile head constraint condition on the characteristics of lateral behavior of single pile. These effects can be quantified only by the results of model tests. Based on the results of model tests, in non-homogeneous sand, it was found that the lateral behavior depends upon the ratio of soil modulus of upper layer to lower one. And, in respect of deflection, it was found that the relationship between the deflection ratio of non-homogeneous to homogeneous sand and the ratio of lower layer thickness to embedded pile length can be fitted to exponential function of H/L and lateral load by model tests results. Also, in respect of maximum bending moment, it was found that the relationship H/L and $MBM_{fixed-head}/MBM_{free-head}$ can be fitted to linear function of H/L by model test results.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.12
• /
• pp.97-106
• /
• 2011

To analyze the lateral load-deflection behavior of steel-concrete composite drilled shafts, a series of lateral pile load tests were performed. The test results were compared with the results from various analytical methods for lateral pile behaviors using the coefficients of subgrade reaction ($k_h$) estimated by pressuremeter test (PMT) and standard penetration test (SPT). As a result, it was found that the analytical methods using the $k_h$ estimated by SPT N value were not suitable for evaluating the pile head lateral load-deflections of the piles within the allowable deflection. However, the methods using the $k_h$ calculated from PMT were able to represent the initial lateral behavior at the head of the piles fairly well. Also, the method by the pressuremeter curve, which was applied directly to the p-y curve of the piles, offered a reasonable lateral behavior estimation by applying the correction factor to the pile materials.

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

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.4 no.2
• /
• pp.77-88
• /
• 1984

By investigating the characteristics of various factors about soil and pile containing in the theoretical equations of lateral earth pressures acting on a row of passive piles which have been already presented in the previous. papers, the equations are arranged as a simple form which is convenient to use. The simplified equation is examined so as to be also utilized to single passive pile. And a discussion is carried out on the method how to apply the equations to field. As the result of this study, the equations can be arranged as a simple linear equation with the coefficients of lateral force $K_{p1}$ and $K_{p2}$. And the simple linear equation is composed of cohesion c and earth pressures ${\sigma}_H$ acting on backside of pile's row against the direction of soil deformation. In order to apply this equation to field, the active earth pressure can be considered as the earth pressure ${\sigma}_H$. The validity of this consideration is justified by comparing the theoretical values of lateral earth pressures acting on piles with the values observed in field.

• Geotechnical Engineering
• /
• v.14 no.6
• /
• pp.153-166
• /
• 1998

This paper shows the results of a series of model tests on the behavior of steel pipe pile which is subjected to lateral and inclined loads in homogeneous and non-homogeneous Nak-dong River sands. Non-homogeneous soil consisted of two layers, upper and lower layer. The purpose of the present paper is to investigate the effect of ratio of lower layer height to embedded pile length, ratio of soil modules of upper layer to lower layer and inclined load on the behavior of single pile. These effects can be quantified only by the results of model tests. As a result. in non-homogeneous sand soil, it is shown that the lateral behavior depends upon the ratio of soil modules of upper layer to lower layer more than other factors. And it was found that the relationship between the deflection ratio of non-homogeneous sand to homogeneous sand and the ratio of lower layer height to embedded pile length can be fitted to exponential function of H/L by model tests results. For the inclined load applied, it is shown that the bending moment-depth relationship is not similar to the case of laterally loaded pile and the depth of maximum bending moment at relative density of 90% increases about 70% more than the pile only loaded laterally.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1991.10a
• /
• pp.348-361
• /
• 1991

When reinforcing strip footing on a sand 8round with reticulated root piles, reinforcing effect depends on the length , number, cross sectional area, penetration angle, spacing, and Young's modulus of piles. the mode of action of reinfocement tendons in soil isn't one of carring developed tensile stresses but of anisotropic(uni-directional) reduction or even supression of one normal strain rate. R. H. Bassett and N. C. Last proposed that the reinforcement should be located on the direction of minor strain rate which coincides with the tensile strain rate in the velocity characteristics. Based on this proposal the author carried out a series of 2 - dimentional finite element analysis which varies the parameters mentioned above.