• Advances in Computational Design
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• v.4 no.4
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• pp.343-365
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• 2019

Among the themes related to earthquake countermeasures at construction sites, those for tower cranes are particularly important. An accident involving the collapse of a crane during the construction of a skyscraper has serious consequences, such as human injury or death, enormous repair costs, and significant delays in construction. One of the causes of deadly tower crane collapses is the destruction of the site joints of the tower crane mast. This paper proposes a new design method by static elastoplastic finite element analysis using a supercomputer for the design of the end plate-type tensile bolted joints, which are generally applied to the site joints of a tower crane mast. This new design method not only enables highly accurate and reliable joint design but also allows for a design that considers construction conditions, such as the introduction of a pre-tension axial force on the bolts. By applying this new design method, the earthquake resistance of tower cranes will undoubtedly be improved.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1248-1253
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• 2009

Although there have been many efforts to reduce accidents on construction sites, such accidents continue to occur. New technologies have recently been developed to improve safety and their performance needs to be evaluated to determine their suitability prior to the application. The assessment for safety performance mainly is conducted depending on qualitative and subjective judgment of supervisors. However, there are rarely proper approaches to assess such qualitative measures. Therefore, we propose a fuzzy-based approach to assessing the performance of a new technology. The assessment of a new technology, called a mobile detector (MD), was carried out as a case study. The output is compared with those by a numerical simulation. As a result, the fuzzy-based performance assessment is shown to be appropriate for this evaluation.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.363-366
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• 2005

When widening or repairing concrete deck slab, there is a joint inevitably. However, joining-construction method have following problem, that is the additional stress in existing part of bridge resulting from the specific process of joining-construction and the difference of amount of shrinkage between new and existing bridge. On this study, compared shrinkage stress of the direct joining construction method with the indirect joining construction method, and concluded the proper substitution rate of expansion cement. The rate of replacement was proper at $10\%$. but more than $15\%$, concrete had excessive expansion and weeker compressive strength. The time of placing closure concrete, considering the shinkage stresses and creep, was suitable in $45\~60$ days after placing the new concrete deck slab.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.387-395
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• 2002

As a result of an increase in population of the Metropolitan area and a steady change of circumstances in many parts, the city is sprawling out into the suburbs. This phenomenon causes the necessity of modification of present urban plan. It is risen as a point of issue that construction systems of new railway routes and underground construction, which should be followed the new urban plan in case of inter-regional railway and regional railway. It is hard to find sufficient financial resources, nevertheless the railway improvement definitely affects regional development and improvement of social environment. Also, there is a limit to government subsidies. In this respect, it is necessary to set up a new idea about movement of existing railway routes and improvement of the equipment. This study examines the present problems of railroad construction system in urban downtown area and introduces a suitable institutional way through referring to the instances of other countries.

• The Korean Journal of Air & Space Law and Policy
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• v.6
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• pp.109-135
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• 1994

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1168-1173
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• 2004

Bridges and tunnels mainly compose the structural system of Kyung-bu high-speed railway in Korea and the prestressed concrete box girder bridges are applied for the most part of bridge structures. Precast full span construction method was practiced in the construction of many prestressed concrete box girder bridges in Kyung-bu high speed railway for the high quality, great construction speed, low construction cost and construction safety. However, there have been no application of this method in continuous bridges until now. Therefore, a new advanced precast full span construction method is developed using pre-tensioning for precast and post-tensioning in alternating the simple span into a continuous bridge system. since the high-speed railway trains can cause dynamic problems in a continuous bridge. This study shows the structural behavior and the construction process of the new advance method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.84-89
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• 2007

In this paper, we introduce a new technique for automatic construction of steel frames in high-rise buildings. Basically, we combine advanced robotic technologies to building construction techniques. Four main topics will be developed such as: 1) Planning and synthesis of automatic construction system, 2) Development of construction factory system with climbing oil-pressured robot, 3) Core techniques for automatic assembly for steel frames, and 4) Intelligent resource management system. We expect that this new technique will increase the construction efficiency and will alleviate the manpower shortage problem in the aging society.

• Journal of Arbitration Studies
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• v.13 no.2
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• pp.489-517
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• 2004

The resolution of the 1993 Uruguay Round and the opening of Korea's construction market in '97 marked the beginning of the globalization of Korea's domestic construction market. Consequently, the process led to changes in contracting procedures, as well as disputes in construction management. With globalization came a rapid realization of reasonable values, which forced the hierarchical vertical relationship between the owners, constructors, and subcontractors into a more equal, horizontal relationship. Once the hierarchical relationship was altered, the late 1990's witnessed a dramatic increase in managerial disagreements, in addition to escalating legal disputes and expenditures. The horizontal relationship was a new concept and brought forth many complexities. Unfortunately, because all of this was new, management of construction disputes was elementary at best. Anticipation of disputes is the key to effective dispute management. This includes thorough reviews of contract documents, document management, construction records, and checklists. Also necessary is the education of owners and contractors with pertinent knowledge concerning dispute management. The following paper focuses on the importance of observing construction disputes in order to facilitate management thereof.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.459-467
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• 2011

Construction errors can have significant effects on project performance. Yet, any attempt to tackle error should be driven by the ability to understand its archetypal nature. This study aims to analyze a variety of construction errors at the execution stage, in order to develop a comprehensive set of categories that shall provide insights about the effect of different error types on the industry. We investigate a database provided by an authoritative source, which includes a number of 256 construction errors that occurred in the year 2009 in Dubai construction industry. Results from this study reveal that the most common error arose from 'poor workmanship' which accounted for 21% of the total encountered faults. The next most common types arose from the 'usage of impaired materials', followed by the 'deviation from an intended dimension'. These observations infer that the majority of construction errors are driven by workers' lack of skill or competence. Moreover, it suggests that execution-oriented errors are the major cause of faults and accidents rather than design errors.

• Journal of Korea Port Economic Association
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• v.25 no.4
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• pp.63-82
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• 2009

The purpose of this study is to construct the logistics infrastructure for the exploitation of Saemangeum New Port that will be constructed in near future. To accomplish the purpose, this paper grasp the change of port logistics circumstances firstly. find out the project of the new port and construct the logistics infrastructure for the new port with the basic facts of the port competitiveness. The construction of the logistics infrastructure for the exploitation of Saemangeum New Port will be conducted as follows ; (1) Construction of logistics environment (2) Planning the port marketing for the extension a logistic market share (3) Construction of logistics chain and IT Network and finally (4) Construction of logistics community.