• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.357-367
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• 2006

Drift design methods using resizing algorithms have been presented as a practical drift design method since the resizing algorithms proposed easily find drift contribution of each member, called member displacement participation factor, to lateral drift to be designed without calculation of sensitivity coefficient or re-analysis. Weight of material to be redistributed for minimization of the lateral drift is determined according to the member displacement participation factors. However, resizing algorithms based on energy theorem must consider loading conditions because they have different displacement contribution according to different loading conditions. Furthermore, to improve practicality of resizing algorithms, structural member grouping is required in application of resizing algorithms to drift control of high-rise buildings. In this study, three resizing algorithms on considering load condition and structural member grouping are developed and applied to drift design of a 20-story steel-frame shear-wall structure and a 50-story frame shear-wall system with outriggers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3619-3626
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• 2015

The coal shed at thermal power plant(T.P.P) is the biggest building on size among nuclear, coal and other power plant industry buildings. This the coal shed of indoor type is mass volume, the size of 6 soccer fields and 73 meter in height. Structural and functional elements take priority over aesthetic factors. The shed is built to make mighty space for structural safety and functional store by using the concrete, $75,000m^3$ on the total of central retaining wall and sub buttress, and the steel frame used by 11,744-ton P.E.B. system. The design requirement on its wall and frame, P.E.B. system's feature, and specific data of main process followed by construction are inquired. The aim of this study is to suggest the design requirement and guide for the indoor type of the coal shed.

• Structural Engineering and Mechanics
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• v.89 no.5
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• pp.479-489
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• 2024

The cracking mechanism in ceramsite aerated concrete block (CACB) infill walls were studied in low seismic fortification intensity coastal areas with frequent occurrence of typhoons. The inter-story drifts of an eight-story residential building under wind loads and a seismic fortification intensity of six degrees were analyzed by using the PKPM software. The maximum inter-story drift ratio of the structure in wind load was found to be comparable to that under the seismic fortification intensity of six degrees. However, when accounting for the large gust wind speed of typhoon, the maximum inter-story drift ratio was much larger than that obtained under reference wind load. In addition, the finite element models of RC frames were employed by displacement loading to simulate two scenarios with and without window hole in the CACB infill walls, respectively. The simulation results show no signs of cracking in both the infill walls with window hole and those without window for the inter-story drift caused by seismic loads and the reference wind load. However, both types of infill walls experienced structural creaking when assessing the gust wind pressure recorded from previous typhoon monitoring. It is concluded that an underestimate of wind loads may contribute substantially to the cracking of frame CACB infill walls in low seismic fortification intensity coastal areas. Consequently, it is imperative to adopt wind pressure values derived from gust wind speeds in the design of CACB infill walls within frame structures. Finally, the future research directions of avoiding cracks in CACB filled walls were proposed. They were the material performance improving and building structure optimizing.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.541-549
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• 2015

This study was conducted to experimentally investigate the seismic retrofitting performance of non-ductile reinforced concrete (RC) frames by introducing engineered cementitious composite (ECC) wing panel elements. Non-ductile RC frame tested in this study were designed and detailed for gravity loads with insufficient or no consideration to lateral loads. Therefore, Non-ductile RC frame were not satisfied on present seismic code requirements. The precast ECC wing panels were used to improve the seismic structural performance of existing non-ductile RC frame. A series of experiments were carried out to evaluate the structural performance of ECC wing panel elements alone a non-ductile RC frame strengthened by adding ECC panel elements. Failure pattern, strength, stiffness and energy dissipation characteristics of specimens were evaluated based on the test results. The test results show that both lateral strength and stiffness were significantly improved in specimen strengthened than non-ductile RC frame. It is noted that ECC wing wall elements application on non-ductile RC frame can be effective alternative on seismic retrofit of non-ductile building.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.26-36
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• 2008

As the height of the light-framed building increases, the lateral load and overturn-moment are increased and the possibility of the building overturn becomes larger. Because the shear wall resists lateral load in light-framed building, the reinforcement of shear wall is required. In order to reinforce the light-framed shear wall, using lag screw fastener type (B-HD) and using bolt type (S-HD) hold-down connectors were applied for test. And domestic larch lumbers, $38{\times}140mm$ and $89{\times}140mm$, KS 2nd grade, were used for the stud. The North American OSB panels were used for sheathing panel. Static loads, load speed 6 mm/min, were applied on top of the wall. As a result, shear strength of the wall that using hold-down connector was improved sufficiently. And when applying the S-HD type hold-down connector, stud should be reinforced against weakening by drilled hole. As increasing the number of lag screw, the number of bolt and the product allowable strength, the strength of shear wall that using hold-down connector was also increased. When applying hold-down connector to light-framed building using 38 mm stud, it must be reinforced by enlarging the thickness of stud like as 38 mm doubled column.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.38-53
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• 2022

In this article, I have summarized and reviewed the concepts and terms surrounding the stamped construction technique, focusing on earthen walls in the Three Kingdoms period. This is because confusion is caused by defining the nature of the earthen walls by using various concepts and terms for each researcher regarding the substance and construction method of the earthen walls. The stamped earth method is a representative ancient civil engineering or construction technique in which a frame is made of plates to form a fortress wall, a fence, and the base of a building, and then soil or sand is poured into it layer by layer and then stamped with a bat to make it solid. Therefore, in order to prove that the earthen wall was built by the stamped earth method, evidence such as a narrow plate, a column for fixing it, long horizontal and vertical wood pieces to support the narrow plate, and traces of pounding the soil must be detected. However, in Korea, there are very few cases where such evidence has been fully excavated, so it is necessary to agree on how strictly the standards for the stamped earth method will be applied. The terms related to the stamped technique mobilized for the construction of the earthen walls were explained with actual examples by dividing the terms related to the concept into terms related to the principle and unit of the stamped plate, and the specific stamped technology. In particular, in Pungnabtoseong Earthen wall, a variety of typical and diverse methods of building the ancient stamped earthen wall were identified so that decisive data could be secured to understand the principles and techniques of the stamped earthen wall. In the future, a more general understanding of the stamped technique will be possible only when more evidence related to it is found in relics other than Pungnabtoseong Earthen wall.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.153-158
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• 2005

The turbulent shear flaw around a surface-mounted vertical wall was investigated using the two-frame PIV(CACTUS 3.1) system. From this study, it is revealed that at least 500 instantaneous velocity field data are required for ensemble average to get reliable turbulence statistics, but only 200 field data are sufficient for the time-averaged mean velocity information The flow has an unsteady recirculation region post vertical wall with bottom gap, followed by a slow relaxation to the fiat-plate boundary layer flow. The time-averaged reattachment length estimated from the streamline distribution is about x/H=3H. The large eddy structure in the separated shear layer seems to have signification influence on the development of the separated shear layer and the reattachment process.

• Steel and Composite Structures
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• v.36 no.5
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• pp.507-519
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• 2020

Double skin composite walls are increasingly popular and have been applied to many safety-related facilities. They come from the concept of composite slabs. Conventional connectors such as shear studs and binding bars were used in previous studies to act as the internal mechanical connectors to lock the external steel faceplates to the concrete core. However, the restraint effects of these connectors were sometimes not strong enough. In this research, a recently proposed unique type of steel truss was employed along the wall height to enhance the composite action between the two materials. Concrete-filled tube columns were used as the boundary elements. Due to the existence of boundary columns, the restraints of steel faceplates to the concrete differ significantly for the walls with different widths. Therefore, there is a need to explore the effect of height-to-width ratio on the structural behavior of the wall. In the test program, three specimens were designed with the height of 3000 mm, the thickness of 150 mm, and different widths, to simulate the real walls in practice. Axial compression was applied by two actuators on the tested walls. The axial behavior of the walls was evaluated based on the analysis of test results. The influences of height-to-width ratio on structural performance were evaluated. Finally, discussion was made on code-based design.

• Journal of the Society of Disaster Information
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• v.12 no.2
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• pp.144-149
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• 2016

Nowaday, most of the low-rise concrete structures which have less than five stories were built before the intensified seismic code was established 2005. According to the fact that our country is not a safety zone ay more, studies are need to reinforce the seismic performance of that structures. The basic frame of low-rise structure are consist of beams and columns with partition walls, therefore that are very weak about secondary wave of earthquake because of the high stiffness. The partition wall are consist of open channel for sunlight or ventilation and intermediate wall. The intermediate walls will enhance the stiffness of columns, but will cause shear failure with short column effects because of the reduced effective depth. But we don't have studies and adequate design code for partition wall effects, therefore some more studies are need for these facts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.440-447
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• 2020

Masonry structures are used as bearing walls in small buildings, but they are generally considered non-bearing walls. They are used as partition walls that divide the interior spaces of the frame structures of buildings. In addition, wetting techniques that use mortar as an adhesive between blocks or bricks in construction are vulnerable to climatic conditions, especially cracks in mortar, which can cause conduction collapse of the walls in seismic loading. The purpose of this research was to propose a dry concrete block construction method that complements the weak axial shear stiffness and improves the weakness of the wet construction method as well as to investigate its structural behavior. In this study, the material properties of concrete blocks were examined, and the seismic performance of the proposed dry assembly structure was verified by structural behavior tests on horizontal cyclic loads. First, in these study results, concrete blocks can be applied to the dry block construction method instead of wet construction methods because they secure more than C-type blocks in KS regulations. Second, the structural performance of the wall against a horizontal cyclic load indicates that the resisting force of the assembly block wall is increased by increasing the horizontal length of the wall, forming several diagonal cracks. Finally, the proposed dry block wall structure requires a seismic performance assessment considering that the ratio of the shape of the wall by height and length is considered a major influence variable on the structural behavior under a horizontal load.