• Journal of Korean Association for Spatial Structures
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• v.13 no.2
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• pp.57-66
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• 2013

There are a number of construction methods to build spatial structures such as erection method, Element method, Block method, Sliding method, Lift-up method and Push-up method. These methods are uneconomical and low accuracy, and require long construction duration because of a need of a scaffold or a tower crane to build spatial roof frame. In this study, the construction method to erect a truss structure was proposed as an economical and easy installation method. The proposed method has end hinges of keel truss and winches with horizontal cable. This method makes safe and accurate production and reduces construction duration because trusses are built on the floor or supporter. The goal of this study is to verify the validity of construction method by building scale model using the proposed method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.145-146
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• 2022

The demand for a construction method capable of securing a safety environment and improving quality is increasing. There is a high risk of falling when working at a high place in an environment where it is difficult to secure visibility, such as an underground space, and there is a risk of falling if cement liquid waterproof materials are transferred to the top of the scaffold by manpower. In addition, when working on a high place in a poor environment, the quality uniformity of the upper part of the wall is deteriorated. In addition, as waterproof technicians gradually age and decrease, it is difficult to secure them, so it is urgent to prepare countermeasures against the shortage of waterproof technicians. Therefore, the purpose of this study is to develop cement liquid waterproof spouting construction equipment that can secure uniform quality of construction areas to prevent accidents and ensure safety of workers, improve work efficiency and quality due to improvement of work environment. The adhesion performance of the cement liquid waterproof material could be improved by about 20% in accordance with the use of the equipment.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.1000-1006
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• 2011

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold, whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged $IC_{50}$ value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

• Journal of Korean Society of Disaster and Security
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• v.12 no.3
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• pp.59-67
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• 2019

In this study, the UAV (Unmammed Aerial Vehicle) was applied for the photogrammetry of the construction site and the safety management of steel pipe scaffold. The research site is a temporary facility for building reinforcement on Samcheok Campus of Kangwon National University. The installation condition of the steel pipe scaffold was investigated, and the pillar distance, the beam distance and the wale distance were surveyed. As a result, it was found that the beam distance of the scaffold in the longitudinal direction was in good agreement with the standard, but the pillar distance and the wale distance were found to be less than the standard. Three-dimensional data can be used in drone shooting to enable three-dimensional measurement, so that it is possible to measure facilities hidden or located inside other facilities. Through the drone shooting, the condition of the site can be quickly recorded and the surveying can be carried out without interfering with the work of the field personnel. Although the installation of the temporary structure must be strictly observed to ensure the safety of the workers, it is found that the installation standards are still neglected in the field. In order to prevent this practice, it was thought that the legal system should be supplemented so that it could be checked periodically by using UAV in the field process management.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.53-62
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• 2014

According to the statistics of occupational injuries in 2013, the work platforms were main objects causing fall injuries in construction sites. But many scaffold and platform workers use and install the work platforms and the fixed and mobile scaffolding without considering about safety and health standards. We had done a nationwide survey about how the platform workers obey safety and health standards. As the result of this survey, in order to ensure the safety of the work platforms, we founded that the platform workers must obey the safety and health standards when using and installing the work platforms. To improve the safety and health conscious of the workers, it needs to educate a worker on safety and health standards for work platforms. Also, to effectively prevent constructin injuries for the work platforms, it is rextricted for workers to use only safety certified work platforms. And, before installing and using work platforms, it needs to make a work plan for work platforms and obey it.

• 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.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1252-1252
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• 2022

Temporary work that utilizes temporary equipment (e.g., system scaffold and system pipe support) in construction work is one of the most vulnerable work from a safety perspective in South Korea. Typically, temporary equipment is reused at construction sites. The Korea Occupational Safety and Health Agency announced guidelines regarding the performance standards for reusable temporary equipment to prevent the accidental collapse of temporary facilities. Nevertheless, temporary facilities' collapse still occurs, which could be attributed to a degradation in the performance due to the reuse of temporary equipment. Therefore, this study investigated the performance of simple temporary structures assembled with new and reused equipment. To this end, an experimental module was designed based on previous research cases, and two experimental models were constructed, in which one was assembled using new equipment (Model A), and the other was built using reused equipment (Model B). To determine the performance of each model, a load test was conducted to measure the maximum load that each model could withstand. The experimental results revealed that the maximum load of Model B was 15% lower than that of Model A. This indicates that there is a meaningful performance difference between those two models. Based on this result, the authors decided to perform additional tests with more realistic models than previous ones. The new experimental module was designed to ensure compliance with the Korean design guidelines. In this presentation, the authors show details of the first tests and their results and plan for the additional test.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.49-58
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• 2020

In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.174-181
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• 2004

We will introduce a method of construction of super-block curtain wall applied to Tower Palace III which is the highest high-rise complex building in Korea. Up-up method is utilized on Tower Palace III to shorten the term of works and it is that the curtain walls for the belt wall part are installed after the rests. The belt wall structure increases the horizontal structural stiffness of the building. The method of construction of super-block curtain wall is developed and used to raise and install the curtain wails of the belt wall floor. It is that the large block of curtain walls corresponding to three stories is fabricated on the ground in advance and the block is installed at a time by a tower crane. Specialized installing equipment :,s newly developed and applied to install the super-block. curtain wail. The curtain wall of the upper floor of the belt wall part is installed after the super-block. The installing equipment for this floor is developed utilizing a mini excavator and vacuum suctions. The application of this method had made it possible to omit the setting up the scaffold and financial profits such as the shortening of the terms of works was realized. The safety of works was secured and the productivity was also improved.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.450-451
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• 2006

The method of conductor wiring is that a messenger wire is installed, the end of the wire is connected to the conductor and a engine puller pulls the conductor. The length of one section of wiring is $3{\sim}5km$ and one group messenger wire pulls simultaneously $2{\sim}4$ group conductor, while a tensioner maintains wiring tension to prevent the deflection of the conductor. However, there are many obstacles such as roads, power lines, communication lines, buildings, farms and crops. Therefore to prevent damage from conductor deflection a staging is used. The currently used staging is scaffolding lumber which is difficult to secure and it's construction efficiency is very low because it requires a lot of time and manpower. So this study developed a insulating defense tube and pipe connecting device, and a truss structure fabrication module using steel pipe which reduces construction time and cost through a compressive and dielectric strength test.