• Title/Summary/Keyword: Temporary structure

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Reliability Analysis of Temporary Structures Considering Uncertainty in Rotational Stiffness at Member Joints (부재 연결부 회전 강성의 불확실성을 고려한 가설 구조물의 신뢰성 해석)

  • Ryu, Seon-Ho;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.87-94
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    • 2019
  • This study deals with the reliability analysis approach of the temporary structure that can consider the uncertainty in rotational stiffness at the joints of the members, for which the semi-rigid connections are modelled as rotational spring and its coefficient is treated as a random variable following uniform distribution. In addition, this study introduces a computational procedure of the effective length coefficient for more accurate buckling load according to connection conditions of the supporting members attached to the joint. From the results of this study, it can be seen that the failure probability of the joint-hinge model (Case 1) presented in the design standard is higher than that of the practical model (Case 5) considering the rotational stiffness at the joints. This implies that the design standard leads to a conservative design of the temporary structure. The results also confirmed that the failure probability of the vertical member, i.e., the most critical member, can be further reduced when the base connection is provided with a fixed end. The comparative results between FORM, SORM and MCS further demonstrated that FORM can have a high level of numerical efficiency while ensuring the accuracy of the solution, compared with SORM and MCS. Based on these results, the proposed approach can be used as an accurate and efficient reliability analysis method of the three dimensional temporary structure.

Development of Individual Temporary Equipment Material/Quality/Delivery Management Standards(Guide) for Temporary Equipment Rental Company (가설기자재 임대업체를 위한 개별 가설기자재 자재/품질/납품관리 기준(Guide) 개발)

  • Lee, Junho;Kim, Junsang;Yoou, Geonhee;Cho, Sehyun;Kim, JungYeol;Kim, Youngsuk
    • Korean Journal of Construction Engineering and Management
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    • v.25 no.1
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    • pp.62-72
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    • 2024
  • Due to the distribution structure of domestic temporary equipment, quality control of temporary equipment is essential because more than 80% of temporary equipment is repeated and reused. Due to this importance, the Ministry of Land, Infrastructure and Transport has proposed quality management standards for temporary equipment for 10types of temporary equipments, including steel pipe support, but the overall quality of temporary eqipment cannot be confirmed because the quality is managed through sampling quality tests. In addition, although quality control standards exist for temporary material rental company, practical utilization was investigated and analyzed to be very low as they are mainly presented based on qualitative inspection standards by visual inspection. Therefore, the purpose of this study is to develop individual temporary material/quality/delivery management standards (Guides) for temporary equipment rental company to preemptively secure the quality of temporary equipment before bringing them into the construction site. If the standards developed through this study are applied to domestic temporary equipment rental companies, it is expected that high-quality temporary equipment with secured quality will be brought into the construction site as the quality of temporary equipment quality of domestic medium and small temporary equipment rental companies is improved safety accidents related to temporary structures.

A Study on Manufacturing Temporary Platform Structure Using Press Forming Processes (프레스 가공 공정을 이용한 가설구조물 제조에 관한 연구)

  • Park, Joon-Hong;Lee, Jae-Sup;Lee, Sung-Keun;Kim, Hyun-Soo;Sung, Ki-ln
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.4
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    • pp.92-97
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    • 2007
  • A temporary structure is a framework of metal poles and planks, used as a working platform from which building repairs or construction can be carried out safety. The manufacturing process of the existing model consumes a many hour. So, it is modified manufacturing process. In this study, it is attempted to find out the shape of modified working platform considering manufacturing process and using Taguchi method, and it reduces production process. The design parameters are defined to discribe shape of model. As a result of the shape design, maximum Von-Mises stress and displacement considering a safety factor were satisfied with CTEA (Construction Temporary Equipment Association of Korea) standard.

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A Methodology of the Static Analysis for Scaffolding Structure (가설공사 비계의 정적구조 해석에 관한 연구)

  • 손기상
    • Journal of the Korean Society of Safety
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    • v.8 no.2
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    • pp.16-22
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    • 1993
  • Accidents, especially fatal accidents in construction work are being not reduced, but increased, despite of more concerns of related authority and companies themselves. It is investigated that major reasons of which these accident increase are caused to set up wrong temporary structures : scaffolding with insufficient components or safety guards. Approximately 50% of falling accident, one of three major accidents; falling collapsing of structures or soil, accidents from heavy equipments, are due to defects of temporary structures. Therefore, technical standards for these temporary structures made by the ministry of labour in 1984, should be promptly revised because of its insufficient considerations for structural concepts. A method to effectively ensure the construction safety are shown through an experimental method, mathematical analysis structural planning against overturning and collapsing of scaffold-ing components, consideration of safety factor in loading, formulations of safety structure against falling or dropping from schaffolding.

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Analytical testing and evaluation of truss typed structures for tunnel maintenance

  • Lee, Dongkyu;Kim, Dohwan;Lee, Jaehong;Noh, Pilsung;Park, Sungsoo
    • Smart Structures and Systems
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    • v.15 no.4
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    • pp.949-961
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    • 2015
  • The goal of this study is to present numerical modeling and analytical testing in order to evaluate an innovative space truss typed temporary structure, which is used to maintenance and repair of road tunnels. The present space truss structure has merits to use UL-700 high strength steel tube as members and to carry out maintenance and repair works of road tunnels without blocking cars and transportations. Numerical modeling and analytical testing of the space truss are investigated by using commercial engineering software, i.e., ABAQUS 6.5-1, and then it is verified that the truss structure has both structural safety and effective function for maintenances and repairs of road tunnels.

Case Study for Buckling Design of Temporary Bridges using System Buckling Analysis (시스템좌굴 해석법을 이용한 라멘형가교 주요부재의 좌굴설계에 관한 사례 연구)

  • Kyung, Yong Soo;So, Byoung Hoon;Bang, Jin Hwan;Kim, Moon Young
    • Journal of Korean Society of Steel Construction
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    • v.19 no.1
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    • pp.87-98
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    • 2007
  • Generally, main girders and steel piers of temporary bridges form the steel rahmen structure. In this study, the rational stability design procedure for main members of temporary bridges was presented using a 3D system buckling analysis and second-order elastic analysis. Six types of temporary bridges, which can be designed and fabricated in reality, were chosen and the buckling design for them was performed in consideration ofload combinations of dead and live loads, thermal load, and wind load. Effective buckling length of steel piers, transition of 3D buckling modes, and effects of second-order analysis were investigated through a case study involving six temporary bridges.

A study on Cross-Platform Search Pattern (크로스 플랫폼에서의 탐색 패턴 연구)

  • Kim, Hwoi-Kwang;Park, Chan-Ik
    • Journal of Digital Convergence
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    • v.16 no.4
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    • pp.321-327
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    • 2018
  • Applications have evolved with the evolution of smartphones, and the search structure is changing as well. In this study, we searched through various cases of cross platform and found out the search pattern and suggested correct usage method accordingly. As a result, the search structure for cross platform can be divided into persistent navigation, temporary navigation, and auxiliary navigation. Persistent navigation is available in a hierarchical structure using springboards, lists, galleries, and top menus. Temporary navigation can take advantage of drawers, toggle menus, and pie menus, while secondary navigation can provide the same experience across platforms using an accordion menu or scrolling.

Structural and Functional Measurements of a Space Truss Frame for Maintenance Works in Tunnels (터널의 유지보수공사 개선을 위한 가설 스페이스 트러스 프레임의 사용성 및 안정성 평가)

  • Lee, Dong Kyu;Kim, Do Hwan;Kim, Jin Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.3
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    • pp.92-98
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    • 2012
  • This study shows details of a specific space truss frame structure devised to carry out maintenance and repair temporary works in tunnels. The purpose of this study is to verify structural safety and function of the innovative truss structure through an analysis tool, i.e.. ABAQUS, which is a suite of software application for finite element analysis and computer aided engineering. And then optimized size, i.e., thickness and diameter of truss members is evaluated in practice. In this study, construction methods in the temporary works are additionally represented by using the new space truss frame structure.

Application of Wireless Measurement System for Safety Management of Temporary Substructures (가설공사 안전관리를 위한 무선계측 시스템 적용)

  • In, Chi-Hun;Rhim, Hong-Chul;Lee, Kun-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.05b
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    • pp.21-24
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    • 2009
  • This study deals with the application of USN wireless inclinometer sensor for earth retaining structure safety measurement, The application of wireless inclinometer sensor has great advantage about real-time monitoring of earth retaining structure, It allows a construction manager to monitor movement data from anywhere connected through internet during the process of excavation for substructures of buildings, To validate the applicability of the wireless inclinometer sensor. laboratory and field tests have been performed, The results have shown that the measured values of wireless inclinometer sensor represent the behavior of H-pile well, Both convenience of sensor installation and real-time monitoring of earth retaining structure are confirmed, The proposed wireless measurement system provides a good basis for exact measurement of temporary substructures, More measurements and application are expected for the other excavation sites with various conditions.

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A Method of All-Weather Construction Application in Construction Sites (건설분야 전천후 공법 적용방안)

  • Lee, Han-Woo;Lee, Byung-Soo;Bang, Chang-Joon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.193-194
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    • 2012
  • Construction work is affected by the weather; e.g. snowfall, rainfall and low-high ambient temperature, especially at a site in a severe climate. The influence of the weather is one of the possible reasons for delays in a construction schedule and quality deterioration. To protect the worksite from severe weather conditions, the temporary roof and wall could be installed on the outside of main structures designed in advance and the temporary structures could be took down after a period use. The greater coverage all-weather construction method is applied, the larger the effect. so, it is important and needs that the temporary roof and wall can be widely applied, designed to effectively about structure and layout.

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