• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.195-202
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• 1995

As the pipe houses were constructed by imitation and routine without a structural design by now, they were often destructed by a strong wind or a heavy snowfall. The purpose of this study was to provide the basic data for the safety structural design of the pipe houses in Kyungpook region to prevent meteorological disaster. It was shown that the change of frame interval according to the safety factor under the wind load was similar that under the snow load. But the safety frame interval under the snow load was approximately 0.5-0.6m greater than that under the wind load for equal safety factor. Therefore, it seemed that the maximum safety frame interval was to be decided by the snow load. The frame of the pipe houses in Seungju region was structurally stable under the design snow load in recurrence intervals of 8-15years, but was unstable in Kolyong region.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.3
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• pp.225-239
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• 2004

In this paper, systematic analyses for the shoring systems installed to support applied loads during construction are performed on the basis of the numerical approach introduced in the previous study. Structural behaviors require changes in design variables such as types of shoring systems, shore stiffness and shore spacing. In this paper, the design variable are analyzed and discussed. The time dependent deformations of concrete and construction sequences of frame structures are also taken into account to minimize structural instability and to improve design of shoring system, because those effects may increase axial forces delivered to shores. From many parametric studies, it can be recommended that the most effective shoring system is 2SlR(two shores and one reshore)

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.221-229
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• 2013

To find the influence of incident angle of wave on the moment of 3 storied steel moment resisting frame which is placed on the concrete rectangular pontoon, the fluid dynamic analysis is carried out, varying the period of wave from 5 to 15 second by 2 seconds. As increasing incident angle of wave to longitudinal axis, the influence of RAO-rolling is increased. The moment of longitudinal frame is increased apparently by the wave pressure when the incident angle is $0^{\circ}$. And the moment of the frame due to the wave pressure is decreased as the incident angle is increased. But the moment of frame due to acceleration caused from pitching and rolling is increased. It is shown that the increased moment when incident angle is $90^{\circ}$ is much greater than that of incident angle $0^{\circ}$.

• Journal of Korean Society of Steel Construction
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• v.17 no.3 s.76
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• pp.253-262
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• 2005

Because the framed wall system using steel studs and runners with square steel tubes as structural elements is reinforced by the horizontal members called runners, it has more strength and load bearing capacity than the steel house wall system. Also, this system improves adiabatic and sound insulation performance by filling up the autoclaved lightweight concrete. We need to evaluate load bearing capacity according to the axial load and lateral load in case this system is applied in the housing system with 3~5 stories through variations in intervals for the runners under the placement effect of autoclaved lightweight concrete. Therefore, this study seeks to analyze axial and shear behavior of the framed wall system according to the placement effect of autoclaved lightweight concrete, and to secure safety for the vertical and lateral loads.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.11a
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• pp.306-315
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• 2002

본 연구는 지역별로 단동비닐하우스의 설치현황, 단면형상, 폭, 지붕높이, 측고, 측벽기울기, 골조재의 규격, 서까래간격, 가로대의 설치위치 및 개수, 내용년수 등을 현장조사를 통하여 비닐하우스의 구조실태를 파악하였다. 설치지역별에 따른 단동비닐하우스의 구조특성을 조사ㆍ분석한 본 연구결과는 관행적으로 시공되고 있는 소형비닐하우스의 구조표준화를 위한 기초자료로 활용할 수 있으며 매년 반복되고 있는 강풍과 폭설로 인한 소형비닐하우스의 피해를 줄일 수 있는 안전모델 개발의 기초자료로 활용할 수 있을 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2242-2248
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• 2015

The damages from greenhouses collapsing due to heavy snowfall in winter are increasing, and the current frames of greenhouse are required to be improved. This study was conducted to seek solutions to improve intensities of greenhouse frame to bear heavy snows. We investigated a structural safety of greenhouses by calculating axial force, bending moment and combined stress when snow load was increased up to 30% of the current standard ground snow load of the conventional greenhouse types (07-single type 3, 07-single type 18) in the three regions (Gyeongju, Sokcho, and Gangneung) where were most damaged by recent heavy snows. In addition, we determined what structural type was most efficiently bear snow loads by measuring the differences between the load bearing strength according to the changes of tube diameter and thickness or the rafter spacing of greenhouses circular pipe. MIDAS GEN program was used in the analysis. As a result, with the snow load increase of 30%, greenhouse in Gyongju was still safe, but in Sokcho was at a risk, and in Gangneung was possible to be collapsed even in the current snow load. Increased pipe diameter than increased pipe thickness was more efficient in terms of improved performance of greenhouse structure. Accordingly, it is suggested to revise standards of greenhouse to increase pipe diameter of rafter for minimizing damages by heavy snow.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.6
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• pp.11-21
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• 2010

This study presents seismic responses of 5-story reinforced concrete structures retrofitted with the buckling-restrained braces using a time-dependent element. The time-dependent element having birth and death times can freely be activated within the user defined time intervals during the time history analysis. The buckling-restrained brace that showed the largest energy dissipation capacity among the test specimens in previous research was used for retrofitting the RC buildings in this study. It was assumed that the first story of the damaged building under the first earthquake was retrofitted with the buckling-restrained braces considered as the time-dependent element before the second of the successive earthquakes occurs. Under this assumption, this paper compares seismic responses of the RC structures with the time-dependent element subjected to the successive earthquake. Subjected to the second earthquake, it was observed that activation of the BRB systems largely decreases deformation of the moment frame where the damage was concentrated under the first earthquake. However, damages to the shear wall systems were increased after activation of the BRB systems. Since the cumulative damages of the shear wall systems were infinitesimal compared with the retrofit effect of the moment frame, the BRB system was effective under the successive earthquake.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.65-70
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• 2001

우리 나라의 온실 설치 면적은 1999년말 현재 51,200ha에 이르고 있으며 그 중 유리온실이 363ha로 0.7%, 철골 경질판 온실이 125ha로 0.2%이고, 아연도강관을 사용한 비닐하우스가 50,712ha로 99.1%를 차지하고 있다. 파이프 골조의 비닐하우스는 대부분 아치형의 지붕 모양을 하고 있으며, 바람에는 비교적 강하나 적설에 약한 구조이다. 전국적으로 가장 널리 분포하고 있는 직경 25.4mm, 두께 1.5mm의 파이프를 사용한 폭 6m의 단동 온실의 경우 서까래 간격 60~80cm일 때 안전 적설심은 10~14cm 정도에 불과하다(남 등, 2000). (중략)

• Tunnel and Underground Space
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• v.20 no.1
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• pp.58-64
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• 2010

GLI model was verified to consider the interaction between a ground and a tunnel lining and to rationally reduce the ground load acting on the secondary lining(concrete lining) of a tunnel. In this study, the economy and the construction condition of tunnel concrete linings designed by a conventional frame model at Lot O of OO line were highly enhanced through a field design change using GLI model. For a few safe considerations, not only about 50% saving of reinforcing steel could reduce the material cost but also the wide space between bars could make it easy to pour concrete mix without voids. There was large saving effect of reinforcing steel for poor ground conditions because Terzaghi's load used in the conventional frame model produces too much high loads for those conditions.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.1-7
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• 2010

Recently, the damage of the farmhouse has been increased due to frequent collapsing accidents of the pipe greenhouse caused by the heavy snow load derived from unusual weather phenomena. However, the study about it is rare and tenuous so that the damage is happened repeatedly. Although there are a few ways to improve the greenhouse such as increasing section, decreasing the distance between rafters in order to avoid the collapsing accidents, those ways have some shortcomings like cost and frame ratio increase, etc. Therefore, this study performed the large displacement analysis considering geometric non-linearity on each load level with respect to many kind of reinforcement methods and analyzed combined strength ratio and stress so as to search the ways, which enhance the structural stability of greenhouse and minimize the frame ratio increase. As a result, this paper is aimed at suggesting the optimal reinforcement method model.