• Journal of the Korean Society for Marine Environment & Energy
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• v.1 no.1
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• pp.102-111
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• 1998

Ocean monitoring facilities are divided into two types, fixed type and floating type. This paper deals with wane load calculation and mooring system for a floating monitoring facility. Wave load and drift forces are calculated for an example case of floating monitoring buoy To enlarge holding power of anchor, circular pile model test was performed. A program for horizontal force of circular pile in sand was made and the calculated result showed fairy good agreement with the result of model test. It is expected that this method will provide good estimation for the holding power of the prototype of circular pile anchor which is relied upon SCUBA activity for installation.

• Journal of the Korean Geotechnical Society
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• v.21 no.2
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• pp.47-55
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• 2005

This paper describes the results for a numerical analysis of'single piles and pile oops in clayey soils subjected to monotonous lateral loading using the ABAQUS finite element software. The investigated variables in this study include free head and embedded capped single piles, pile diameter (1.0 m, 0.5 m), pile length (7.0 m, 10.0 m), and pile groups. The 1$\times$3 pile group was selected to investigate the individual pile and group lateral resistance, the distribution of the resistance among the piles, the effects of lateral stresses in front of and on the sides of the piles, and the effect of a cap on the lateral resistance of the leading pile. The soil was modeled using Cam-clay constitutive relationship and the pile was considered as a elastic circular concrete pile. The results show that the size of the cap influences lateral capacity of sin pile. The results also show in pile groups, the pile-soil-pile interaction and the cap effect the resistance in the leading pile, and the p-multiplier for the leading pile of greater than 1.0 was able to be obtained.

• Journal of Korean Society of Steel Construction
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• v.24 no.2
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• pp.175-188
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• 2012

A parametric study for varying the radii of curvature is performed with a curved tub girder bridge having three continuous spans. The bracing forces of top lateral bracings from the results of numerical equations are compared to those of 3-dimensional finite element analyses. New modifying factors applicable in computing the nominal member forces of top lateral bracings were suggested. The numerical equations were derived based on one girder system, and it is shown that the numerical equations exhibit some errors compared with 3D FEA results. The main reason for this phenomenon lies on the number of girders. The twin girder system has an external cross-beam between inner and outer girder. It also has larger lateral stiffness than the single girder system. Finally, the distributions by the torsion, bending, distortion, and lateral loading of the top lateral bracing forces were presented in this paper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.687-695
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• 2020

Micropile is used to improve the stability of existing structures as well as solve various geotechnical problems, such as suppressing slope activity and shearing keys of retaining walls. The existing micropile method has a significantly less capacity to resist a horizontal force than a vertical force0355 Therefore, it is necessary to develop and study an umbrella-type micropile method with excellent seismic performance that can secure seismic performance economically while minimizing structures and ground disturbance areas in the limited space of existing structures. In this study, numerical analysis was performed on the umbrella-type micropile, in which the sloped pile and vertical pile were combined, and the horizontal behavior in soft clay ground during earthquakes was analyzed. Numerical analysis showed that umbrella-type micropile suppresses horizontal displacement in soft ground, and the effect of reducing the horizontal displacement was more pronounced when the embedded depth of the slope pile was 15 m or more. The embedded depth of the micropile and horizontal displacement suppression effect was proportional. Therefore, the umbrella-type micropile has an excellent effect of suppressing horizontal displacement during earthquakes on soft clay ground.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.45-48
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• 2008

Under earthquake loads, the columns on the lower stories carry large axial forces and horizontal forces as the earthquake loads are acting horizontally and vertically on the building. To distribute the energy entered into the building under earthquakes according to the plastic deformation of the members, it is safer and more economic to persuade plastic hinge to occur in the beams rather than on the columns. However, it is unavoidable to have plastic hinge occurring on the columns when it is applied on both of the main axes of the building, which results in high shear force on the column end, and reinforced concrete column may result in sudden brittle failure due to bending moment and shear force. To increase restriction of the reinforced concrete column on the horizontal forces, this study uses repetitive loading experiments with different amount of shear reinforcement, and analyzes and compares the structural safety and behaviour of the reinforced test materials.

• Journal of the Korean Geotechnical Society
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• v.23 no.2
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• pp.61-69
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• 2007

In this study, experimental analysis was performed about lateral load capacity and behavior of laterally loaded-bored piles for soil conditions and pile shape, i.e. cylindrical and taper piles. Also, Calibration chamber load tests were performed for cylindrical and taper piles considering the variations of relative densities and restraint stresses. According to the results of chamber tests, it was found that, while both vertical and horizontal stresses affect load-responses and ultimate lateral load capacity of laterally loaded piles, effect of the horizontal stress was larger than that of the vertical stress. Effect of lateral load capacity and behavior was relatively small compared to relative density and stress state of soils surrounding piles, but showed a little difference for soil conditions. From comparison between predicted and measured lateral load capacity, it was observed that predicted results differ significantly from measured results. This is mainly due to the fact that the effect of horizontal stress is not considered in the conventional prediction methods.

• Journal of the Korean GEO-environmental Society
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• v.22 no.4
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• pp.15-23
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• 2021

Various micropiles have been developed through research related to micropiles, which have been carried out with the increased use of micropiles. Among the micropile construction methods being developed, the triaxial micropile (tmp), which is recently developed for the purpose of increasing the horizontal bearing capacity (seismic resistance), is representative. The three-axis micropile has the advantage of a method that can resist horizontal load more effectively because three micropiles installed inclined on each axis resist horizontal load. However, there is a problem in effectively using this pile method due to insufficient research on the support characteristics of the triaxial group micropile. In order to effectively utilize the triaxial group micropile (tmp), it is required to evaluate the bearing capacity for the factors that affect the horizontal bearing capacity of the pile. Therefore, in this study, field horizontal loading Tests were performed for each load direction, field loading Tests were verified through three-dimensional finite element analysis, behavioral characteristics of triaxial micropiles were evaluated, and appropriate horizontal bearing capacity was analyzed in consideration of horizontal load directions.

• Computational Structural Engineering
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• v.7 no.1
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• pp.83-90
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• 1994

This study presents the nonlinear dynamic analysis method of the bridge with the seismic isolation bearing. Also the numerical analyses are performed for investigating the response characteristics of the bridge isolated with the lead-rubber bearing under the ground motions compatible to Korea bridge design response spectra. It is found that the pier design force can be considerably smaller than the one for the bridge with the fixed bearing. It is observed that the lead-rubber bearing has the great effectiveness for reducing the longitudinal seismic force in case of the bridges with low and medium periods. Therefore the seismic isolation bearing can be used instead of the fixed bearing for the economic and safe design of the bridge.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.69-75
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• 2009

The load distribution and deformation of pile-bent structures are investigated using a numerical study. A numerical analysis that takes into account the effects of varying cross-sectional area was performed for different pier diameters, loading steps, and soil conditions. Through the comparison study, it is shown that the location of maximum bending moment is almost the same per each loading step, regardless of varying cross-sections. However, the member force (i.e., stress of pile material) has the largest value at the ground surface when the cross-section is changed. Based on the results obtained, it is found that the location of maximum member force influences highly the behavior of pile-bent structure with varying cross-sections for repair works.

• Geotechnical Engineering
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• v.3 no.3
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• pp.21-30
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• 1987

Some methods are presented to estimate the ultimate lateral resistance of single active piles subjected to lateral loads above the ground surface, considering the lateral soil reaction, the pile length and the fixity condition of a pile head. The lateral soil reaction acting on a single active pile embedded in soil due to pile movement can be estimated by use of a theoretical equation which is derived by considering especially the plastic state of ground surrounding the pile and the pile- section shape. The piles are named short or long depending upon the relative magnitude of the induced bending moment to the yielding moment. As for the fixity condition of a pile head, the free head and the unrotated head are considered. Comparison with other experimental results gives that the calculated ultimate lateral resistance obtained by the author's theory is closer to experimental results than the one obtained by Brom's theory.