• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.612-615
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• 2004

Today, the curtain wall is used in many construction projects because of excellent economical efficiency and constructability. The life-cycle process of curtain wall construction consists of the architectural design, curtain wall design, manufacturing, const겨ction, and maintenance phase which has become one of the most important objects that have to be managed. Since the general management method focused on each separated phase, it has accompanied many problems such as increases of the cost and duration, and loss of productivity. To solve these problems, it is necessa교 to have a new management method based on supply chain management. Thus this research analysed the processes of stick system, semi-unit system, unit system, and panel system classified by the type of the curtain wall, and suggested proper methods of application of SCM concept to each type of curtain wall construction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1911-1918
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• 2014

The increase of input resources, such as labor and equipment, in a construction project causes workspace interference between activities and it influences on the productivity and quality of construction activities. To solve this problem, many studies related to the workspace interference have been performed, however they verified the workspace concerning with only the geometric location of activities or generated the shape of workspace by a whole object concept not separated units of detailed operations. It is difficult for project manager to reasonably analyze the workspace conflict, because the size of workspace cannot reflect the characteristics of an activity and input time of a resource. This paper presents a methodology that can generate three-dimensional models in order to optimize the workspace shape and size by considering with the characteristics of each activity and input time of each resource. The suggested method can be used for the active BIM system that optimizes the workspace conflict without additional construction duration and for the searching algorithm of optimized moving path for construction equipment.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.257-262
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• 2019

Lattice steel towers for overhead transmission lines have been replaced by tubular steel poles due to the visual impact of large and complex shape of truss type. Demand for tubular steel poles consisting of a single frame member continues to grow because of its advantages such as visual minimization, architectural appeal and minimal site consumptions. However, there are some constraints on the transportation and construction. As the diameter of tower base has been enlarged, it may exceed minimum height limit required to pass the tunnel in case of land transportation. Also, in a narrow place where it is not easy to secure the installation areas such as mountainous places, there might be some areas wherein it must secure a wide working space so that large vehicles and working cranes will be allowed to enter. In this paper, we presented a vertical separated tubular steel pole, which is a new type of support that can be implemented for general purpose such as mountainous areas or narrow areas to improve the issues raised by breaking away from the conventional design and fabrication methods. Technical approaches for overcoming the limit of the cross-sectional size is to separate and modularize the cross-section of the tubular steel pole designed with a size that cannot be carried or assembled, and to lighten it with a weight capable of being transported and assembled in a narrow space or mountainous area. As a result of this research, it will be possible to enter small and medium sized vehicles in locations where it is restricted to transport by large-sized vehicles. In the case of mountainous areas, it will be possible to divide it into a weight capable of being carried by a helicopter and it will be easy to adjust and fabricate it with individual modules. Furthermore, in order to break away from the traditional construction method, we proposed the equipment that can be applied to the assembly of Tubular Steel Pole without using a large crane in locations where there is no accessible road or in locations wherein large cranes cannot enter. In particular, this paper shows the movable assembling equipment and some methods that are specialized for vertical separated tubular steel pole consisting of members with reduced weight. The proposed assembly equipment is a device for assembling the body of the Tubular Steel Poles. It will be installed inside the support and the modules can be lifted by using the support itself.

• Tunnel and Underground Space
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• v.23 no.2
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• pp.87-98
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• 2013

Around 70% of Korea is mountainous, an increase in tunnel construction. It's due to the growing interest of the public for the environment and land required for the road construction is very scarce. During construction of 'Daedong 1 tunnel' in the expressway expansion project between Naengjeong and Busan, there are shallow shaft due to this tunnel located in the valley and the shafts are separated, and penetrating location change was inevitable for construction was delayed because of complaint. So, we change the position of the penetrating by applying multi-channel TSP, and conducted a stability analysis. The analysis results showed that there is no problem on the stability of the tunnel. To secure the construction of additional stability, We installed instrument, performed mechanical excavation, added reinforcement at shallow shaft and conducted bench cut.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.222-228
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• 2024

This study aims to anal yze the social benefits of introducing a sel ective demol ition system for buil dings. Incremental revenue, incremental cost, and incremental profit for the entire nation were derived based on the calculated costs and revenues of selective demolition for a 2,400 m² apartment complex. In conducting selective demolition on a 2,400 m² building, the increase in demolition construction costs, the reduction in waste disposal costs due to the decrease in mixed waste, and the revenue obtained from recycling separated and sorted waste were comprehensively reviewed. It was calculated and analyzed that, compared to general demolition work, a total cost-saving effect of 34,727,000 KRW could be expected. Extrapolating this to the entire nation, based on the year 2020, which had the highest construction waste generation, it is estimated that the social benefits would amount to 746,782,886,000 KRW.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.869-875
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• 2009

Safety is a big issue in the construction sites. For safe and secure management, tracking locations of construction resources such as labors, materials, machineries, vehicles and so on is important. The materials, machineries and vehicles could be controlled by computer, whereas the movement of labors does not have fixed pattern. So, the location and movement of labors need to be monitored continuously for safety. In general, Global Positioning System(GPS) is an opt solution to obtain the location information in outside environments. But it cannot be used for indoor locations as it requires a clear Line-Of-Sight(LOS) to satellites Therefore, indoor location monitoring system could be a convenient alternative for environments such as tunnel and indoor building construction sites. This paper presents a case study to investigate feasibility of Wi-Fi based indoor location monitoring system in construction site. The system is developed by using fingerprint map of gathering Received Signal Strength Indication(RSSI) from each Access Point(AP). The signal information is gathered by Radio Frequency Identification (RFID) tags, which are attached on a helmet of labors to track their locations, and is sent to server computer. Experiments were conducted in a shield tunnel construction site at Guangzhou, China. This study consists of three phases as follows: First, we have a tracking test in entrance area of tunnel construction site. This experiment was performed to find the effective geometry of APs installation. The geometry of APs installation was changed for finding effective locations, and the experiment was performed using one and more tags. Second, APs were separated into two groups, and they were connected with LAN cable in tunnel construction site. The purpose of this experiment was to check the validity of group separating strategy. One group was installed around the entrance and the other one was installed inside the tunnel. Finally, we installed the system inner area of tunnel, boring machine area, and checked the performance with varying conditions (the presence of obstacles such as train, worker, and so on). Accuracy of this study was calculated from the data, which was collected at some known points. Experimental results showed that WiFi-based indoor location system has a level of accuracy of a few meters in tunnel construction site. From the results, it is inferred that the location tracking system can track the approximate location of labors in the construction site. It is able to alert the labors when they are closer to dangerous zones like poisonous region or cave-in..

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.527-538
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• 2011

Currently, the only established criteria is on the location of bus stops on principal roads where uninterrupted flow mainly occurs. There are no clear guidelines on any method to locating bus stops considering the characteristics of bus operation and pedestrians. If the location or exterior of a bus stop is inappropriate, road users including bus drivers and pedestrians will be caused serious dangerous and inconvenience. In this study, the research below was performed in order to propose rational criteria for the location of bus stops integrated with or separated from speed-change lanes at signalized intersections considering smooth traffic flow and the characteristics of bus operation and pedestrians as well as traffic safety : First, the appropriate length of each of the near-side and far-side bus stops was calculated by categorizing bus stops to be constructed into those integrated with speed-change lanes and those separated from speed-change lanes. Secondly, the appropriate length of each of the bus stops divided into near-side bus stops and far-side bus stops and integrated with or separated from speed-change lanes was selected by considering the characteristics of pedestrians. Thirdly, whether the construction locations of bus stops were appropriate or not was determined based on the appropriate length of bus stops integrated with or separated from speed-change lanes, which was calculated and selected by considering traffic flow and the characteristics of pedestrians and considering traffic safety. The method for locating bus stops considering traffic flow, the characteristics of pedestrians, and traffic safety will be able to help suggestion criteria of bus stop and the location of safe and pleasant bus stops.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.292-298
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• 2016

In this research, considering the practical situation of separated placing method for mass concrete structure, an efficient method of controlling the heat of hydration is suggested by comparing between the simulated values and actual measurements conducted with the optimum mix design obtained from the various mix conditions with different types and amount of supplementary cementitious materials(SCMs). As the result of the research, firstly, the optimum mix designs for top and bottom layers were determined by Midas gen as OPC to FA of 85 to 15, and OPC to FA to BS of 50 to 20 to 30, respectively. The concrete mixtures prepared with the mix designs determined from the simulation satisfied the target performance range in slump, air content and compressive strength. Additionally, from temperature measurement for the actual mass concrete placed during spring, the maximum temperature difference between surface and core was about $10^{\circ}C$ with 59 and $49^{\circ}C$ for top and bottom layers, respectively, and 1.4 of cracking index was obtained. Therefore, considering the practical conditions of mass concrete construction, it is considered that the different heat of hydration method using different mix designs with SCMs can be an efficient method for controlling thermal cracking and settling cracking of mass concrete.

• Korean Journal of Environment and Ecology
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• v.32 no.4
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• pp.392-412
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• 2018

This study was conducted from 2012, which was a year before forest road construction in Minjujisan, to 2015 to verify effects on flora and vegetation change annually before and after the construction, and to provide strategies to examine and manage flora changes. The plant communities in the investigated area around the forest road is separated by the slopes into Quercus mongolica community is on the northwestern slope and Quercus variabilis and Larix kaempferi communities is on the southwestern slope. The annual investigation of flora change before and after the construction showed that there were 209 taxa that had 71 families, 153 genera, 178 species, 27 varieties, and 4 forma in 2015 while there were 66 taxa that had 44 families, 59 genera, 51 species, 13 varieties, and 2 forma in 2012 before the construction, indicating an increase of 143 texa before and after the construction. The investigation of the slope area adjacent to the forest road constructed in 2013, in particular, showed increasing coverage and taxa each year after the construction. This was caused by significantly increased light transmittance after the construction. The investigation in 2015 showed increased coverage of herbaceous layer the year after development of the forest road and the remarkable increase of the coverage of shrub layer in 2015. Further, the coverage on the slope adjacent to the forest road increased more in 2015 than in 2013 and 2014. Therefore, we expect supplementary studies will help to generate a detail manual on flora and vegetation change before and after forest road construction.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.184-193
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• 2013

Procurement System for Korean construction industry has mainly been controlled by the complicated regulatory system which has been recognized as unflexible and remotely separated from the global standard. This has been identified by many Korean construction experts as one of the main reasons that hamper the Korean construction industry becoming the global leader. One commonly discussed regulatory system is the compulsory multiple contracting system that has been enforced for a long time. According to the Korean governmental contracting law 68-3, all construction projects cannot be divided into separate contracting packages with a few exceptions. Exceptions stated in the law include construction activities related electrical, Information communication, fire-fighting, and cultural assets which all are governed by the separate laws/acts controlled by the different governmental bodies. This research is to closely investigate multiple prime contracting system that has been compulsory in Korean construction industry and to provide policy recommendations to these restrictions. Although, there has been a long history of this compulsory contracting system, this study attempted to provide objective analysis on current status of the system as well as global standard on the issue. This study suggests main considerations when considering different contracting system such as rights of owners, flexibilities of regulatory systems, and efficiencies of conducting a construction project. It is envisioned that recommendations from this study, if accepted by the regulatory bodies, would improve the Korean construction contraction system by making it more compatible with global standard. Moreover, these would help making the Korean industry more effective in terms of regulatory restrictions.