• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.325-326
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• 2009

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.115-123
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• 2015

The study conducted statistical analysis of survey on the 239 workers participating in national Tower Crane installation/dismantlement in order to identify work environment and health hazard exposure of Tower Crane workers. Consequently for work related safety status of Tower Crane workers, the number of installation/dismantlement work was the highest at 15-20 times per month, and safety equipments were not arranged at work and they felt highly anxious when boarding on the Tower Crane. Furthermore, it is found that they feel anxious working in the influence of the weather, noise, vibration, wind, the sun ray, and structure characteristic. They have very low satisfaction in the insecureness of workplace and the work environment, and recognizes that their work affect highly on the health. 81.6% of workers have experienced accident at work, the cause of accidents were mainly due to poor work environment, and the health abnormality they have experienced were mostly fatigue and concentration reduction. For job stress, job demand and conflict in relationship were the highest sections. Total 66.5% of workers complained of musculoskeletal disorder related subjective symptom, and back pain patients were the highest of all groups.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.44-45
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• 2019

Tower cranes are essential equipments that play a key role in the overall process of large-scale construction projects, as well as high-rise apartments construction projects. Tower cranes hoist various loads near and over people, working in crowded environments, sometimes in overlapping work areas, and often under the constraints of time, budget, and labor. This work system further increases the safety risks of sites with inherently hazardous workplaces. The methodology of this research was based on a comprehensive inquiry of a team of experts, including safety managers and equipment managers of major construction companies and previous literature search. Due to the limited resources available to improve safety and prevent accidents, more attention should be paid to all parties involved in factors that have been evaluated to have a significant impact on site safety due to tower crane operations.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1060-1067
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• 2009

The selection and operation of tower cranes at construction sites are dependent on the personal experience of engineers in charge of lifting work. It often causes to overestimate the safety factor resulting in increase of construction cost, or underestimate it resulting in disastrous accident. Therefore, selection of tower cranes needs to consider cost, safety and maximum lifting condition. This study, for resolving such problems, was intended to propose the algorithm designed for even the inexperienced person to select the optimal lifting equipment in timely manner. The algorithm presented herein is an optimization algorithm that enables automatic arrangement of tower crane and minimization of costs by analyzing such conditions as vertical height and lifting load, etc.

• Journal of the Korea Institute of Construction Safety
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• v.2 no.2
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• pp.63-69
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• 2019

Building Construction projects are getting higher and larger. Therefore, the use of Tower Crane, which is more productive than any other lifting plan shows a trend of continuous increases. However as equipment for transporting heavy goods, are is too expensive for the monthly rent and used inefficiently for construction. site so it is analyzed that it has problems of reducing productivity and efficiency of lifting work. Inefficient situations are arising like poor communications between operator and worker, occurrence of blind spots, securing the shortest distance of fire during movement after lifting plan, influences of weather, location of materials, movement radius of tower crane by each locations and ever-changing working environments. Therefore, in this study, we first made a list of tower cranes that are inefficiently used at the site, and then we made a checklist. After that, through field visits, we derived checklist for Tower Crane to comprehensive data value.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.58-68
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• 2009

The purpose of this study is to suggest new subject to satisfy the lack parts of examination course of the existing driving tower crane certificate by using the DACUM method. For this, problems of education for the existing driving tower crane certificate and the existing subjects are examined and, based on these, comparing analysis of new subjects that follows the DACUM method and the existing subjects are conducted. The results of this study that were progressed following the purpose and method at the above are as follow : 1) It is analyzed that the existing subjects for the driving tower crane certificate could not be applied to construction fields immediately and the education to deal with disorders when driving the tower cranes. 2) The number of the subjects that have been advanced following the DACUM method is seven and those consist of five theoretical subjects and two practical subjects. It is analyzed that the developed and suggested subjects can be used in construction fields when considering the theoretical and practical parts in no time.

• Advances in Computational Design
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• v.4 no.1
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• pp.53-72
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• 2019

Safety measures for tower cranes are extremely important among the seismic countermeasures at high-rise building construction sites. In particular, the collapse of a tower crane from a high position is a very serious catastrophe. An example of such an accident due to an earthquake is the case of the Taipei 101 Building (the author was the project director), which occurred on March 31, 2002. Failure of the bolted joints of the tower-crane mast was the direct cause of the collapse. Therefore, it is necessary to design for this eventuality and to take the necessary measures on construction sites. This can only be done by understanding the precise dynamic behavior of mast joints during an earthquake. Consequently, we created a new hybrid-element model (using beam, shell, and solid elements) that not only expressed the detailed behavior of the site joints of a tower-crane mast during an earthquake but also suppressed any increase in the total calculation time and revealed its behavior through computer simulations. Using the proposed structural model and simulation method, effective information for designing safe joints during earthquakes can be provided by considering workability (control of the bolt pretension axial force and other factors) and less construction cost. Notably, this analysis showed that the joint behavior of the initial pretension axial force of a bolt is considerably reduced after the axial force of the bolt exceeds the yield strength. A maximum decrease of 50% in the initial pretension axial force under the El Centro N-S Wave ($v_{max}=100cm/s$) was observed. Furthermore, this method can be applied to analyze the seismic responses of general temporary structures in construction sites.

• Journal of Construction Engineering and Project Management
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• v.5 no.4
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• pp.7-11
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• 2015

The luffing-tower crane (T/C) is a key facility used in the vertical and horizontal transportation of materials in a tall building construction. Locating the crane in an optimal position is an essential task in the initial stages of construction planning. This paper proposes a new optimization model to locate the luffing T/C in the optimal position to minimize the transportation time. A newly developed mathematical formula is suggested to calculate the transportation time of luffing T/C correctly. An optimization algorithm, the Harmony Search (HS) algorithm, was used and the results show that HS has high performance characteristics to solve the optimization problem in a short period of time. In a case study, the proposed model offered a better position for T/C than the previous heuristic approach.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.420-424
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• 2015

The luffing-tower crane (T/C) is a key facility used in the vertical and horizontal transportation of materials in a tall building construction. Locating the crane in an optimal position is an essential task in the initial stages of construction planning. This paper proposes a new optimization model to locate the luffing T/C in the optimal position to minimize the transportation time. An optimization algorithm, the Harmony Search (HS) algorithm, was used and the results show that HS has high performance characteristics to solve the optimization problem in a short period of time. In a case study, the proposed model offered a better position for T/C than the previous heuristic approach.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.27-32
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• 2024

In this study, based on accident cases of manned and unmanned tower cranes, the types and causes of accidents were analyzed and tower crane accident prevention measures were proposed accordingly. As a result, 'lack of communication' was commonly analyzed as the biggest cause of accidents. Therefore, in this study, we investigated domestic and international systems and laws regarding signalmen responsible for communication between tower crane operators and workers and proposed the following three improvement methods. First, the signalman system must be legally and institutionally reestablished. Second, national agencies and private organizations with expertise should create standardized training manuals and distribute them to signalman educators, and create checklists to manage educators. Third, in the case of a site using a tower crane, the employer must mandatorily deploy a signalman with professional qualifications. Lastly, the results of this study are expected to highlight the differences in accident types and causes of manned and unmanned tower cranes and the need for legal and institutional improvement in the signal system.