• The Journal of Engineering Geology
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• v.27 no.3
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• pp.331-343
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• 2017

In this study to improve stability, workability and economics of the H-Pile+Earth plate or H-Pile+Earth plate+Cutoff grouting currently in use, we had developed HCS method belonging to the retaining wall which is consisting of a combination H-Pile, Plastic Sheet Pile and Steel Square Pipe for gap maintenance and reinforcement of flexible plastic Sheet Pile, and the behavior of each member composing HCS method is investigated by three-dimensional finite element analysis. To numerically analyze the behavior of the HCS method, we have performed extensive three-dimentional finite element analysis for three kinds of plastic Sheet Pile size, two kinds of H-Pile size and three kinds of H-Pile installation interval, one kinds of Steel Square Pipe and three kinds of Steel Square Pipe installation interval. After analyzing the numerical results, we found that the combinations of $P.S.P-460{\times}131.5{\times}7t$ (PS7) and H-Pile $250{\times}250{\times}9{\times}14$ (H250), $P.S.P473{\times}133.5{\times}9t$ (PS9) and H-Pile $300{\times}200{\times}9{\times}14$ (H300) is the most economical because these combinations are considered to have a stress ratio (=applied stress/allowable stress) close to that as the stiffness of H-Pile, plastic Sheet Pile and Steel Square Pipe composite increased, the horizontal displacement of the retaining wall and the vertical displacement of the upper ground decreased. Especially, due to the arching effects caused by the difference in stiffness between H-Pile and plastic Sheet Pile, a large part of the earth pressure acting on plastic Sheet Pile caused a stress transfer to H-Pile, and the stress and displacement of plastic Sheet Pile were small. Through this study, we can confirm the behavior of each member constituting the HCS method, and based on the confirmed results of this study, it can be used to apply HCS method in reasonable, stable and economical way in the future.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.811-818
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• 2010

This paper presents the results of a numerical investigation on behavior of deep excavation wall system supported by steel pipe struts. A series of three-dimensional finite element analyses were carried out on a deep excavation project site which adopted steel pipe struts. The results indicated that the mechanical behavior of steel pipe supported deep excavation is comparable to that of a conventional H-pile supported deep excavation, although the steel pipe supported system is required less number of struts than the conventional H-pile strut system. Also shown is that the sectional stresses of the steel pipe support system are within the allowable values implying that the steel pipe support system can be effectively used as an alternative to conventional H-pile support system.

• Journal of Korean Association for Spatial Structures
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• v.15 no.3
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• pp.85-93
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• 2015

This paper presents a foundation pile to steel column connection that can resist large magnitude of moment and that can be easy installed. The developed joint has spherical shape and it is given the name HAT joint to mean Hallow half-sphere steel joint. Four types of HAT joints are developed. Namely, H-type, T-type, P-type and K-type. In this paper I will talk about the performance assessment of T-type(Tube Column) and P-type(Pile Column) of HAT joints with finite element analysis and experiment on a full scale model is presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.185-186
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• 2021

In Korea, many buildings are built with underground spaces and cast-in-place pile method is mostly applied in the temporary retaining walls for the underground space construction. A H-shaped steel section is generally embedded in the soldier pile in the C.I.P method. In this study, a new and economical section with high strength steel replacing the H-shaped section was proposed and its flexural capacity was evaluated experimentally. The new section is the concrete-filled composite section with pentagonal thin plate and thick flange plate. Test results showed that the proposed section has an excellent flexural strength and ductility.

• Journal of Korean Association for Spatial Structures
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• v.15 no.4
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• pp.65-72
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• 2015

To overcome the weakness of spread foundation in large space structure, the research of precast pile for replace spread foundation have been conducted. The new type of joint between PHC pile and steel column is named HAT Joint(Hollow hAlf-sphere cast-sTeel Joint). It connected PHC Pile by bolt that verification of bolt connection should be accomplished. In this paper, pull-out test and flexural performance for HAT Joint to verifying the bolt connection is explained. As a result, the pull-out and flexural capacities of bolt were checked to use in real structure. Furthermore, the equation of pull-out strength was proposed.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.563-570
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• 2016

The composited structural member in which two or more materials having different stress-strain relationships (steel & concrete) has increased greatly in recent years. This paper presents the experimental results of flexural capacity of the composited H-Pile subjected to bending moment. Eight composited beams were tested under direct loading condition using the frame tester. Based on the experimental results it is noted that flexural capacity of composited H-Pile increased about 20~30% and ductility ratio significantly increased. Limit state analysis of the specimens was conducted and the result shows that flexural strength by limit state analysis is conservative.

• Journal of the Korean Geotechnical Society
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• v.26 no.6
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• pp.45-56
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• 2010

This paper presents the results of a numerical investigation on the behavior of deep excavation wall system supported by steel pipe struts. A series of three-dimensional finite element analyses were carried out on a braced excavation case which adopted steel pipe struts. The results indicated that the mechanical behavior of the steel pipe supported braced excavation is comparable to that of a conventional H-pile supported excavation, although the steel pipe supported system allows a larger longitudinal spacing than the conventional H-pile strut system. Also shown is that the sectional stresses of the steel pipe support system are within the allowable values. This implies that the steel pipe support system can be effectively used as an alternative to conventional H-pile support system.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.559-562
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• 2003

The results and discussions of surveyed case site at constructed steel pile in potential acid sulfate soil were as follows. Topography at surveyed site was local alluvial valley and that site soils was classified as BanGog and YuGye series as detailed soil surveyed results in RDA and soil texture was Clay/Clay Loam. Soils pH was neutral, which was average 7.5 but much decreased to average 4.2 after $H_2O_2$ treatment. Organic matter and sulfate ions contents were very rich. The corrosion was severe at ground water fluctuation depth. Deposits colored black were attached to steel pile surface, which because of violent reaction in treatment HCI solution, were guessed as corrosion products (FeS) reduced by sulfate reducing bacteria(SRB). Consequently, main cause was thought microbiologically induced corrosion at this site where there is ground water fluctuation occurring oxidation and reduction reactions in turn and the soil is potential acid sulfate soil.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.1-10
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• 1998

The temporary steel bridges which are constructed for detour and constructional expediency are consisted of H-beams(as superstructure) and H-piles(as substructure). Because these members are fastened by high-tension bolts, there are no expansion joints in these bridges. So, these kinds of bridges have no system which can relieve the excessive thermal stress. In this investigation, monitoring system was set up at temporary steel bridge and stress and temperature changes of H-beam are monitored. From these measured data, it is analyzed that the relationship between ambient and main-girder temperature change, between temperature and stress change. With these analyses, it is resulted that the thermal stress take main part of stress variation in this bridge and the restrain of thermal longitudinal displacement of H-pile. In addition, because the connection part of H-beam to H-beam is weak in the continuous spans, the sub-modelling is well apt to reflect the effect of thermal stress.

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