• Steel and Composite Structures
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• v.13 no.3
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• pp.259-275
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• 2012

Concrete filled steel tubular (CFST) member has been widely used in the construction of high-rise buildings for its high axial bearing capacity. It can also be applied on long-span structures such as spatial structures or bridges not only for its high bearing capacity but also for its construction convenience. Concrete casting effect of CFST member is considered in the study of its bearing capacity in this paper. Firstly, in order to authenticate the applicability of constitutive relationship and yield criterion of steel and concrete based on FEM, two ANSYS models are built to simulate and compared with other's test. Secondly, in order to find the huge difference in bearing capacity due to different construction processes, two full-size CFST models are studied when they are horizontally cast and axially compressed. Finally, the effects of slenderness ratio (L/D) and confining parameter (D/t) of CFST members are studied to reveal the intrinsic links between bearing capacity and slenderness ratio or confining parameter.

• Journal of the Korean Geosynthetics Society
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• v.9 no.2
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• pp.11-20
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• 2010

This paper studies the discharge capacity of vertical drain boards that is controlling hydraulic gradient among many factors in the specification. The KS K 0940(2008), a testing method based on the conventional Delft type method for measuring the discharge capacity of a vertical drain, was specified in Korea Standard recently. In this test method, the variation in hydraulic gradient can result in large differences in the discharge capacity for the same vertical drain board.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.12
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• pp.173-180
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• 2019

Construction work is a labor-intensive industry, which is required systematic production activities using materials, manpower, and equipment. Among them, manpower resources play a very important role in achieving efficiently production in the organization. Construction work is highly dependent on construction craft workers, and the level of proficiency can be directly related to the construction productivity and quality. However, a rapidly aging construction craft workers in Korea, is being replaced by a foreign construction craft workers because of advoidance of new laborers in the construction site. In the future, if the continuous development and management of construction manpower is not made properly, it may be lead to adverse effects such as setbacks in production, delayed completion, faulty construction, industrial disasters, and decreased productivity in construction site. In this study, it was proposed four important factors for work capacity management of construction craft workers. These were ensuring of physical strength through the health management of construction craft workers, securing of proficiency through career management, ensuring of productivity through work capacity and establing of informatization through work capacity management. By introducing a systematic system, it is possible to improve construction craft workers' professionalism, enhancing the level of welfare, reflecting the realities of labor costs, increasing the quantitative and qualitative levels of construction craft workers, Futhermore it was demanded the continued interest and policy support for the realization of effective management of construction craft workers.

• Journal of the Korean Society of Safety
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• v.24 no.4
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• pp.59-65
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• 2009

This paper presents the safety performance of domestic small-sized construction companies including the characteristic and current status of safety management actions of the firms. Safety performance both at the head office and job sites of each construction companies, which are divided two groups by construction capacity ranking, are investigated. The investigation results on the small-sized construction companies in this study was compared with those of on the large and medium-sized construction companies studied in existing papers. General recognition that there is a wide difference of safety performance among domestic construction companies by construction capacity ranking was companies by this study. Especially, Data analysis shows that the safety performance of the small-sized companies has the larger difference than large and midium-sized companies.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.129-136
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• 2013

This research was conducted to investigate effects of acid buffering capacity and soil component in treatment of phenanthrene using electrokinetic-Fenton process. In Hadong clay of high acid buffering and low iron oxide content, it was difficult to oxidize phenanthrene due to shortage of iron catalyst and scavenger effect of carbonate minerals. The desorbed phenanthrene conductive to Fenton oxidation was transported toward cathode by electroosmotic flow. However, in Youngdong illitic clay, oxidation of phenanthrene near anode readily occurred compared to Hadong clay due to high iron content and low acid buffering capacity.

• Earthquakes and Structures
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• v.18 no.5
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• pp.599-607
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• 2020

This paper deals with the experimental investigation on the behavior of RCS beam-column exterior joints. Two full-scale specimens of joints between reinforced concrete columns and steel beams are tested under cyclic loading. The objective of the test is to study the effect of steel fiber reinforced concrete (SFRC) on the seismic behavior of RCS joints. The load bearing capacity, story drift capacity, ductility, energy dissipation, and stiffness degradation of specimens are evaluated. The experimental results point out that the FRC joint is increased 20% of load carrying capacity and 30% of energy dissipation capacity in comparison with the RC joint. Besides, the FRC joint shown lower damage and better ductility than RC joint.

• Journal of the Korea Institute of Building Construction
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• v.6 no.4 s.22
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• pp.45-52
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• 2006

Top Down method is more widely used in downtown construction, recently. As underground construction constitutes a significant portion of the total construction cost and time in Top Down construction, it is important to develop a construction method to reduce the time required in underground works. The purpose of this study is to analyze load carrying capacity of Top Down prefounded columns on different excavation schedule. When several floors are excavated, the valid buckling length of prefounded column is increased and allowable buckling stress is decreased. The result shows that all columns are safe in buckling down to B3 story whether 2 or 3 stories are excavated. However, several columns are not safe from B4 story when 2 or 3 stories are excavated straightly. With these results, a process can be designed that the first three stories in the basement are excavated, and then excavate B4 story after placing concrete on B1 and B2 floor.

• Proceedings of the Korean Geotechical Society Conference
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• 1997.10a
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• pp.409-416
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• 1997

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.666-668
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• 1992

This paper shows a reasonable design standard of electric equipment capacity for office buildings, that was made by the systematic and statistical way considering actual conditions, such as investigated electric equipment capacity, electric power consumption, etc for 121 buildings. The saving of electric equiment investment, the decrease of power loss, the improvement of facilities utilization and the decreasse of electric power rates can be contributed by the application of the design standard.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.58-65
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• 2004

Recently, the top & down method with drilled shafts as a foundation of high rise building is often adopted for the purpose of construction period reduction and construction cost effectiveness. It is common to omit the loading test as a Quality assurance on account of the high capacity of drilled shafts for the top & down method. It seems that the capacity of drilled shaft in recent top & down method is beyond that of conventional loading test method.However, the quality assurance for the drilled shaft as foundation of high rise building becomes much more important since the drilled shaft should bear much higher working load. It may be a small scale test pile could be an alternative as a quality assurance for the drilled shaft with high capacities. Through a case study, this paper gives an idea for solving the limitation of the conventional loading test method for the quality assurance of drilled shaft with high capacities. In particular, this paper analyzed the scale effect for a small drilled shaft installed into bedrock, which could be used for an alternative.