• Steel and Composite Structures
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• v.21 no.1
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• pp.177-194
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• 2016

The cable-supported ribbed beam composite slab structure (CBS) is a new type of pre-stressed hybrid structure. The standard construction method of CBS including five steps and two key phases are proposed in this paper. The theoretical analysis and experimental research on a 1:5 scaled model were carried out. First, the tensioning construction method based on deformation control was applied to pre-stress the cables. The research results indicate that the actual tensile force applied to the cable is slightly larger than the theoretical value, and the error is about 6.8%. Subsequently, three support dismantling schemes are discussed. Scheme one indicates that each span of CBS has certain level of mechanical independence such that the construction of a span is not significantly affected by the adjacent spans. It is shown that dismantling from the middle to the ends is an optimal support dismantling method. The experimental research also indicates that by using this method, the CBS behaves identically with the numerical analysis results during the construction and service.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.58-65
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• 2004

Recently, the top & down method with drilled shafts as a foundation of high rise building is often adopted for the purpose of construction period reduction and construction cost effectiveness. It is common to omit the loading test as a Quality assurance on account of the high capacity of drilled shafts for the top & down method. It seems that the capacity of drilled shaft in recent top & down method is beyond that of conventional loading test method.However, the quality assurance for the drilled shaft as foundation of high rise building becomes much more important since the drilled shaft should bear much higher working load. It may be a small scale test pile could be an alternative as a quality assurance for the drilled shaft with high capacities. Through a case study, this paper gives an idea for solving the limitation of the conventional loading test method for the quality assurance of drilled shaft with high capacities. In particular, this paper analyzed the scale effect for a small drilled shaft installed into bedrock, which could be used for an alternative.

• Structural Engineering and Mechanics
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• v.42 no.4
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• pp.489-505
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• 2012

In this study, it is aim to perform the construction stage analysis of suspension bridges using time dependent material properties. Fatih Sultan Mehmet Suspension Bridge connecting the Europe and Asia in Istanbul is selected as an example. Finite element models of the bridge are modelled using SAP2000 program considering project drawing. Geometric nonlinearities are taken into consideration in the analysis using P-Delta large displacement criterion. The time dependent material strength variations and geometric variations are included in the analysis. Because of the fact that the bridge has steel structural system, only prestressing steel relaxation is considered as time dependent material properties. The structural behaviour of the bridge at different construction stages has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. As analyses result, variation of the displacement and internal forces such as bending moment, axial forces and shear forces for bridge deck and towers are given with detail. It is seen that construction stage analysis has remarkable effect on the structural behaviour of the bridge.

• Journal of Ocean Engineering and Technology
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• v.20 no.3 s.70
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• pp.61-66
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• 2006

The estuary has a very complex coastline and bottom topography. Before the close of floodgate, the Keum river estuary was deposited with sediment from the Keum river, created bythe construction of the Keum river estuary dike. So, a periodical dredging is necessary to assure water depth for boat entry and departure to Kunsan port. Theof this study is to find the change of tidal current of M2tide and the topography before and after construction at the Geum River estuary dike. The change of water depth is investigated by digitizing the sea map (No.305) of Kunsan port, which was edited by National Oceanographic Research Institute. The calculated co-range and co-tidal charts of M2tide before the dike construction are similar to the observed ones. Therefore, the amplitude and phase after construction at Geum River estuary dike increases compared to before construction at Geum River estuary dike. The scour occurred in the A-A' section.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.423-428
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• 2007

The 21st century is that both human and environment live together. The advancing knowledge concerning our environment instigates a change in understanding about the physical surroundings. The construction field particularly induces significant improvements that are environmental-friendly. To convene this demand, several manuals and guidelines related to the environmental issues have been enacted and amended. Especially the manuals and guidelines issued from Ministry of Environment (MOC) and Ministry of Construction and Transportation (MOCT) is requiring the addition of environmental knowledge in construction technology. Recently, environmental assessments and advanced environmental measures in various kinds of construction are persuasively been carried out. The policy of Total Maximum Daily Load is the one more reason for the revisions of the manual and guideline, which is really requiring the addition of the environmental knowledge in construction technology. Therefore, this research is focusing on revising the manuals and guidelines related to road construction and maintenance works issued from MOCT.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.204-208
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• 2013

CO2 emission makes up more than 80% of whole green gas. Therefore CO2 is recognized as the main culprit of global warming. IPCC (Intergovernmental Panel on Climate Change) is advising the 3 methods measuring CO2 emission. TIER1 is measured CO2 emission by criteria the energy consumption, TIER2 measure by criteria the emission factor according to the emission control technique each kind of vehicle, TIER3 is measured by criteria the distance each kind of vehicle. Currently, the most of CO2 emission measurement is used by TIER1. But it is not standardized that CO2 emission measurement method have the factor as work condition each distance. Specially, it is not suggest that methodology has the condition changing load of equipment according to site condition and the same position work as construction equipment. So, this study is suggested the CO2 emission measurement methodology of construction equipment.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1279-1280
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• 2005

• Journal of the Korea Institute of Building Construction
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• v.21 no.3
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• pp.213-219
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• 2021

Change orders that occur frequently during the construction phase, af ect the construction performance in terms of cost, time, quality, safety and environment, and place a huge burden for stakeholders of given projects. This study analyzed the causes of change orders and their impact on the basis of 721 cases and a questionnaire of 164 domestic U.S. military construction participants in a total of 24 U.S. military projects. Important factors for change orders in the US military construction projects were engineering change due to design errors (348 cases, 48.3%), user requests change(86 cases, 11.9%), and different site conditions (69 cases, 9.6%). In addition, due to the change orders, construction cost increased by 6.56% on average and construction period was extended by 21.1% compared to the original schedule. As a result, it is anticipated that domestic construction companies can obtain a better understanding of change orders and construction performance, which may be difficult due to accessibility and limitations to military facilities. Also, it is proposed a successor study that guides in the right direction for the U.S. Military Construction.

• Smart Structures and Systems
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• v.13 no.6
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• pp.891-899
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• 2014

Over the past several decades, substantial amounts of sensors and sensing systems have been developed for civil infrastructure systems. This special issue focuses on state-of-the-art robotics and automation technologies, including construction automation, robotics, instrumentation, monitoring, inspection, control, and rehabilitation for civil infrastructure. The issue also covers construction informatics supporting sensing, analysis and design activities needed to operate smart and sustainable civil infrastructure. Examples include robotic systems applied to civil infrastructure and equipped with various sensing technologies, such as optical sensors, laser sensors, wireless sensors, multi-sensor fusion, etc. This special issue is published in an effort to disseminate current advances of various robotics and automation technologies for civil infrastructure and built environment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1599-1608
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• 2014

This study is to suggest specialty contractors with countermeasures to construction orders falling off, one of the construction business indicators for the construction industry, by analyzing the impact of dwindling construction orders to business performance indicators of specialty contractors as well as identifying inter-relationships between those performance indicators. For specialty contractors of civil construction, it is analyzed that their current ratio is significantly affecting obtention of construction orders, which in turn greatly affecting the ratio of owner's equity. It seems that the amount of construction orders has a direct relationship with the corporate stability. Therefore, this type of specialty contractors are determined to be able to obtain more orders for construction by improving current ratio.