• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.190-198
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• 2008

Recently construction equipments have been used in line with building the structures that have become taller, larger and complex. And as the works at the elevated level for apartment and residential-commercial building projects have been on the rise, the number of tower cranes mobilized tends to be increased too. Due to such an increase in using the equipment serves the critical factor for the project management. The climbing-type tower crane, which increases its height following the structure, has been increased and the need for selecting the optimal model has been increasingly Important in securing the stability. The study hereby proposes the model to evaluate the stability of the climbing-type tower crane. The model was designed to assist in selecting the type of crane as well as in developing the design of Collar comprising the 3 types of support member, evaluating the stability and designing the embed. The model proposed is expected to make commitment in selecting the optimal type of equipment and evaluating the support member and embed for enhancing the stability, thereby ultimately enabling to implement the prefect in efficient way.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.50-60
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• 2018

Recently, modular construction method has been widely applied to projects with repetitive processes including dormitory, the residential facility, and the hotel construction due to reduced labor input and shortened construction schedule. Generally, about 40% of total on-site construction cost excluding unit installation cost, is put on exterior finishing work, and thus management of finishing work is deemed important in maintaining the targeted schedule and cost. Since limited equipment is shared so that subsequent activities are not affected while carrying out on-site installation and finishing work, lifting plan becomes more important for modular projects with greater portion of finishing work load. In this regard, tower crane operation plan may take the form of a single cycle or multiple cycles in which equipment efficiency can be affected. However, difficulties exist in evaluating alternatives to tower crane operation plans supporting unit installation and finishing work. Therefore, this study aims to evaluate the alternative of tower crane operation method according to the cyclic period setting in modular building site to determine the effect on T/C uptime and process by parameterizing lifting time for unit and exterior finishing material, lift cycle for unit and exterior finishing material and time required for finishing work. Accordingly, this study develops a simulation model that can increase the tower crane efficiency by controlling the work speed. An academic contribution of this study is to suggest a resource leveling method applying the concept of lifting cycle, and further is expected to be managerially used as a basis for an alternative evaluation of equipment plan.