• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.419-425
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• 2010

In order to examine the P.H.C pile raw material using glass forming ceramic. The used materials is ordinary portland cement, waste TFT-LCD glass powder and reactive agent(Ca$(OH)_2$). The first experiment is characteristics analysis of the waste TFT-LCD glass powder, For the second experiment is mortar and concrete compressive strength for using of the concrete file raw material for waste TFT-LCD glass powder. The results of experiment showed that the substitution ratio of 10% waste TFT-LCD glass powder and 1% reactive agent(Ca$(OH)_2$) was excellent at a point of view for the physical characteristic. The study's most important finding is that the recycling of waste TFT-LCD glass powder.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.127-149
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• 2003

The bridge tested was 3 spans 90m-long PSC beam concrete bridge with a stub-type abutment which had a skew of 60$^{\circ}$ about the axis of bridge. A cement concrete was placed at the superstructural slab of the bridge. Inclinometers and straingauges were installed at piles as well. During 7 days-curing of superstructural slab, the pile behavior in response to hydration heat and drying shrinkage of the slab was monitored. Then monitored values were compared with the horizontal movement obtained from the HACOM program and the calculated lateral behavior obtained from the nonlinear p-y curves of pile. As a result, lateral behavior of H-piles by the field measurement occurred due to the influence of hydration heat and drying shrinkage obtained during curing of superstructural concrete. The lateral displacements by hydration heat and drying shrinkage were 2.2mmand 1.4mm respectively. It was observed as well that the inflection point of lateral displacement of pile was shown at 1.3m down from footing base. It means that the horizontal movement of stub abutment did not behave as the fixed head condition of a pile but behave as a similar condition. The measured bending stress did not show the same behavior as the fixed head condition of pile but showed a similar condition. The increment of maximum bending stress obtained from the nonlinear p-y curves of pile was about 300(kgf/$\textrm{km}^2$) and was 2 times larger than measured values regardless of installation places of straingauges. Meanwhile, lateral load, maximum lateral displacement, maximum bending stress and maximum bending moment of pile showed a linear behavior as curing of superstructural concrete slab.

• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.10-18
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• 2013

The pilot scale biopile system was designed and operated for evaluation of bioremediation efficiency for petroleum contaminated soil. The pilot scale biopile consisted of biopile dome, aeration system and monitoring system and two biopiles were operated with nutrients and inoculum for more 100 days. The test pile A and B were analyzed with regard to pH, total carbon contents, water contents, nutrients (N, P) and TPH. The initial TPH concentrations for pile A and pile B were about 10,000 mg/kg and 2,300 mg/kg, respectively. After 100 days, the TPH contents decreased about 70% in the pile A and 30% in the pile B. Also, n-$C_{17}$/pristane and n-$C_{18}$/phytane ratios in all pile were significantly changed. The microbial densities in the pile A was increased by approximately $10^7$ CFU/g-soil~$10^8$ CFU/g-soil, but there was almost no changed in the pile B. The average biodegradation rates were calculated about 66.8 mg/kg-day in the pile A and 10.9 mg/kg-day in the pile B. Over the course of operation period, pile temperature was considered the major limiting factor for the efficiency of all biopiles.

• Interaction and multiscale mechanics
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• v.3 no.1
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• pp.55-79
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• 2010

The effect of soil-structure interaction on a single-storey, two-bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the finite element analysis with realistic assumptions. Initially, a 3-D FEA is carried out independently for the frame on the premise of fixed column bases in which members of the superstructure are discretized using the 20-node isoparametric continuum elements. Later, a model is worked out separately for the pile foundation, by using the beam elements, plate elements and spring elements to model the pile, pile cap and soil, respectively. The stiffness obtained for the foundation is used in the interaction analysis of the frame to quantify the effect of soil-structure interaction on the response of the superstructure. In the parametric study using the substructure approach (uncoupled analysis), the effects of pile spacing, pile configuration, and pile diameter of the pile group on the response of superstructure are evaluated. The responses of the superstructure considered include the displacement at top of the frame and moments in the columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation considered in the study. Fair agreement is observed between the results obtained herein using the simplified models for the pile foundation and those existing in the literature based on a complete three dimensional analysis of the building frame - pile foundation - soil 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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.93-101
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• 2010

When doing underground excavation works for the purpose of constructing large underground structures for a building in the limited space in downtown area, the stability of the adjacent ground must be top priority, and to accomplish this, it is essential to review the retaining wall construction carefully. H-Pile, which has been mainly used as a stress-carrying material in temporary earth-retaining structures, is most likely to be abandoned after completion of the works for the basement exterior wall in relation to contiguous bored piles, so it will result in a waste of material. To improve this situation, Basement Composite Wall where H-Pile and basement wall are compounded, has been developed. This wall is being used most frequently in many local construction sites. In this study, five specimens are made in order to evaluate the shear resistance of the basement composite wall and tested. Test parameter is the composition ratio and wall thickness according to shear connectors. Test result shows that the shear strength is improved when the composite ratio is increased but the magnitude is not much. A formula, which considers the contribution of concrete, web of H-pile as well as flange' effect in calculation of shear strength of composite basement wall, is suggested and used to calculation of the strength of specimens. It is found that there is a good co-relation between test result and the calculated one by the formula.

• Coupled systems mechanics
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• v.7 no.4
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• pp.455-483
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• 2018

The study deals with physical modeling of a typical three storeyed building frame supported by a pile group of four piles ($2{\times}2$) embedded in cohesive soil mass using three dimensional finite element analysis. For the purpose of modeling, the elements such as beams, slabs and columns, of the superstructure frame; and that of the pile foundation such as pile and pile cap are descretized using twenty noded isoparametric continuum elements. The interface between the pile and the soil is idealized using sixteen node isoparametric surface element. The soil elements are modeled using eight nodes, nine nodes and twelve node continuum elements. The present study considers the linear elastic behaviour of the elements of superstructure and substructure (i.e., foundation). The soil is assumed to behave non-linear. The parametric study is carried out for studying the effect of soil- structure interaction on response of the frame on the premise of sub-structure approach. The frame is analyzed initially without considering the effect of the foundation (non-interaction analysis) and then, the pile foundation is evaluated independently to obtain the equivalent stiffness; and these values are used in the interaction analysis. The spacing between the piles in a group is varied to evaluate its effect on the interactive behaviour of frame in the context of two embedment depth ratios. The response of the frame included the horizontal displacement at the level of each storey, shear force in beams, axial force in columns along with the bending moments in beams and columns. The effect of the soil- structure interaction is observed to be significant for the configuration of the pile groups and in the context of non-linear behaviour of soil.

• Interaction and multiscale mechanics
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• v.2 no.4
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• pp.397-411
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• 2009

The effect of soil-structure interaction on a simple single storeyed and two bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the three dimensional finite element analysis with realistic assumptions. The members of the superstructure and substructure are descretized using 20 node isoparametric continuum elements while the interface between the soil and pile is modeled using 16 node isoparametric interface elements. Owing to viability in terms of computational resources and memory requirement, the approach of uncoupled analysis is generally preferred to coupled analysis of the system. However, an interactive analysis of the system is presented in this paper where the building frame and pile foundation are considered as a single compatible unit. This study is focused on the interaction between the pile cap and underlying soil. In the parametric study conducted using the coupled analysis, the effect of pile spacing in a pile group and configuration of the pile group is evaluated on the response of superstructure. The responses of the superstructure considered include the displacement at top of the frame and moments in the superstructure columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation used in the study. The percentage variation in the values of displacement obtained using the coupled and uncoupled analysis is found in the range of 4-17 and that for the moment in the range of 3-10. A reasonable agreement is observed in the results obtained using either approach.

• 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.

• Geomechanics and Engineering
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• v.34 no.4
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• pp.397-408
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• 2023

Pipe pile walls are commonly used as retaining structures for excavation projects, particularly in densely populated coastal cities such as Hong Kong. Pipe pile walls are preferred in reclaimed land due to their cost-effectiveness and convenience for installation. However, the pre-bored piling techniques used to install pipe piles can cause significant ground disturbance, posing risks to nearby sensitive structures. This study reports a well-documented case history in a reclamation site, and it was found that pipe piling could induce ground settlement of up to 100 mm. Statutory design submissions in Hong Kong typically specify a ground settlement alarm level of 10 mm, which is significantly lower than the actual settlement observed in this study. In addition, lateral soil movement of approximately 70 mm was detected in the marine deposit. The lateral soil displacement in the marine deposit was found to be up to 3.4 and 3.1 times that of sand fill and CDG, respectively, mainly due to the relatively low stiffness of the marine deposit. Based on the monitoring data and site-investigation data, a 3D numerical analysis was established to back-analyze soil movements due to the installation of the pipe pile wall. The comparison between measured and computed results indicates that the equivalent ground loss ratio is 20%, 40%, and 20% for the fill, marine deposit and CDG, respectively. The maximum ground settlement increases with an increase in the ground loss ratio of the marine deposit, whereas the associated influence radius remains stationary at 1.2 times the pipe pile wall depth (H). The maximum ground settlement increases rapidly when the thickness of marine deposit is less than 0.32H, particularly for the ground loss ratio of larger than 40%. This study provides new insights into the pipe piling construction in reclamation sites.