• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.438-441
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• 2009

휨강성이 작은 바닥시스템인 플랫 플레이트 구조는 응력조건 뿐만 아니라 사용성조건에 의하여 구조적 성능이 결정될 수 있으며, 특히 과도한 시공 하중의 작용은 시공 중 안전성에 대한 단기적인 손상 뿐만 아니라 사용성에 관련된 장기적인 손상을 발생시킬 수 있다. 이러한 플랫 플레이트의 시공하중은 동바리지지 층 수, 시공주기, 슬래브 콘크리트의 재료적인 강성 뿐만 아니라, 동바리의 강성과 슬래브에 발생하는 균열에 의한 영향에 의하여 결정된다. 본 논문에서는 다양한 설계조건에 대한 해석연구를 통하여, 동바리-슬래브의 강성비 변화 및 콘크리트 균열에 의한 단면강성저하가 슬래브들 간의 하중 분포에 미치는 영향을 분석하고, 이러한 동바리 강성 및 슬래브 균열의 영향을 고려한 시공하중 산정법을 제안한다.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.848-855
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• 2003

During concrete placement, the partially distributed load due to the concrete placement paths creates the lateral force in the connection parts of the shore. In order to restrain this lateral force, the nails must be used in the upper and lower connection parts of shores. But, for the convenience of the construction and dismantling of the shores, the workers hardly use the nails. In this case, the connections of shore cannot resist the shear force and rotation. And this situation may cause the collapse of form-shore system. Therefore, contact and spring models for the connection analysis of the form-shore systems are required. If we take into account this construction situation, we need to understand the effects of shear and rotation stiffness according to the several types of connection parts in shores as a case study. This study evaluates the shear and rotation stiffness of the connection parts of shores according to the variations of the lengths, numbers and positions of nails, and then presents the experimental results depending on the end conditions of shores. And, these results can be used as a spring model and critical load evaluation data for the connection analysis of form-shore system.

• The Safety technology
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• no.158
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• pp.52-53
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• 2011

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.33-40
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• 2021

In recent years, many construction projects become large and complicated, and construction accidents also steadily increase, which grows interest in the safety and maintenance during construction. Many of the construction accidents are related to temporary construction and structures, but the safety evaluation and management during construction are unclear and indefinite due to the short operating period and continuous change in the formation of the temporary structure. The system support, which is one of the temporary structures to support the pouring load of concrete, was proposed to easily install and dismantle members with connection parts pre-manufactured. The use of the system support is increasing to improve the safety of the temporary structure during construction. However, the system support, which consists of multiple members, still has uncertainties in connectivity between members and supports of vertical members. Therefore, this study analyzed the structure, load, and accident cases of the system support to define the damage scenarios for member connection, support condition, and lateral displacement. The decrease rate of the critical load was analyzed according to the damage scenarios based on the defined unit structure of the system support. In addition, this study provided vulnerable members for each damage scenario, which could induce instability of the temporary structures during design, construction, and operation of the structure.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.517-526
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• 2023

To avoid arbitrary design and excessive braces of system supports with high reusability in the field, this study aimed to propose connection conditions for the vertical and horizontal joints of the system supports based on performance evaluation. Disk-type and pocket-type connection materials, widely used in domestic construction sites, were selected for evaluation of rotational stiffness based on load directions(vertical and horizontal) and loading methods (monotonic and cyclic). Contrary to the current design standards specifying a rotational stiffness of "0" for connection materials, the experimental results revealed that, contrary to the current design standards specifying a rotational stiffness of "0" for connection materials, all specimens exhibited rotational stiffness values. The maximum rotational stiffness was observed to be 19.624 kNm/rad in specimens subjected to repeated loading in the vertical direction using disk-type connection materials.

• The Safety technology
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• no.170
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• pp.54-57
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• 2012

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.113-120
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• 2020

Safety accidents, called industrial accidents in construction work, are causing a lot of casualties, property damage and social controversy in the event of an accident, causing the construction to lose public confidence. The risk of safety accidents at construction sites may continue to increase as the construction of high-rise, large-scale, and multi-purpose complex buildings has increased in recent years. In particular, the most frequently constructed apartment construction among reinforced concrete buildings is designed and constructed with a wall-like structure with no beams for each floor, while the lower floors are made of lamen with columns and beams. As a result, the transfer beam or transfer slab to withstand the upper load is installed on the upper part of the Ramen structure, so the system Dongbari, which is installed as a temporary material during concrete laying construction, may collapse at any time during plowing and curing. The purpose of this study is to apply IT convergence technology to prevent the collapse of the system Dongbari during concrete installation, and to apply many of the variables that may occur during construction on a case-by-case basis to check the stability of the system Dongbari and to propose a model of the anti-conducting prediction system.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.410-417
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• 2013

Long-term behavior analysis considering construction sequence should be performed in the design and the actual construction of reinforced tall buildings. Most of the analytical studies on this subject, however, has not been applied directly to the structural design and the construction caused by the simple approach. As the axial force redistribution of shores and columns is time-dependent, the actual construction sequence with the placement of concrete, form removal, reshoring, shore removal, and the additional load application is very important. Object-oriented analysis program considering construction sequence, especially time-dependent deformation in early days, is developed. This system is composed of input module, database module, database store module, analysis module, and result generation module. Linkage interface between the central database and each of the related module is implemented by the visual c# concept. Graphic user interface and the relational database table are supported for user's convenience.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.159-166
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• 2012

During concrete placement, the formwork structure supports the weight of concrete mass. The complexity of the operation can cause concentrated workloads, which in turn brings about a collapse of the temporary structure. As a countermeasure, the operation needs to be constantly monitored to maintain safety and prevent accidents. This paper presents a USN (Ubiquitous Sensor Network)-based safety monitoring system for formwork construction. The system takes advantage of ubiquitous technology in monitoring the behavior of the formwork structure such as deflection, load weight, and tilting. The collected data are sent to the host computer wirelessly for real time monitoring. The data can be then compared with the allowed limits on guidelines. The comparison can indicate whether the concrete placement operation is executed in a safe condition.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.349-360
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• 2017

In concrete construction work, formwork is an important process that accounts for 10% of the total construction cost. Recent buildings are becoming bigger and higher. In order to maximize the efficiency and safety of this formwork, the system of formworking has been systematized. However, the human accidents and the noise complaints arise from dismantling processes frequently occur. In order to solve these problems, most of them are dependent on foreign technology, but they do not take into consideration the conditions of domestic construction site. In this study, we developed a table type multi-drop system form for a slab and beam which can improve the process, safety and reduction of disassembly noise, and evaluated the physical properties of the main members which are used in the system. The results of this study show that there is sufficient strength to be used as a slab and a laying material for both a yoke beam and a supporting post. The noise level is improved compared to existing method.