• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.329-338
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• 2024

Purpose: This study verified the safety of the improved box-type girder behavior by comparing and evaluating the bending behavior results of a full-scale specimen based on the analytical behavior of the splice element PSC U-shaped girder with integrated tensioning systems. Method: Based on the results of the service and strength limit state design using the bridge design standard(limit state design method), the applied load of a 40m full-scale specimen was calculated and a static loading experiment using the four-point loading method was performed. Result: When the design load, crack load, and ultimate load were applied, the specimen deflection occurred at 97.1%, 98.5%, and 79.0% of the analytical deflection value. When the design load, crack load, and ultimate load were applied, the crack gauge was measured at 0.009~0.035mm, 0.014~0.050mm, and 6.383~5.522mm at each connection. Conclusion: The specimen behaved linear-elastically until the crack load was applied, and after cracks occurred, it showed strainhardening up to the ultimate load, and it was confirmed that the resistance of bending behavior was clearly displayed against the applied load. The cracks in the dry joints were less than 25% of grade B based on the evaluation of facility condition standard. The final residual deformation after removing the ultimate load was 0.114mm, confirming the stable behavior of the segment connection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.86-93
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• 2020

The demand for maintenance in Korea infrastructure facilities constructed since the 1970s has increased significantly compared to the demand for new construction. Moreover, after the Gyeongju and Pohang earthquakes, seismic performance evaluation, repair, and retrofitting projects have been carried out. Therefore, in this study, a specimen was designed following the L-type GFRP Plate Externally Bonded Retrofit method, one among other retrofit methods. The L-type GFRP Plate was bonded to the specimen by epoxy and a washered steel nail. A four-point bending test was performed to confirm the strengthening effect of the Externally Bonded Retrofit method using an L-type GFRP Plate. The strengthening effect of the L-type GFRP plate was proven experimentally, and the behavior of the beam designed following the L-type GFRP Plate Externally Bonded Retrofit method was evaluated according to Korea's "Design Manual & Specification for Strengthening of RC Structures by Advanced Composites System". Furthermore, the effectiveness of the bonding method, a combination of epoxy and washered steel nail, was also checked. The results showed that the design, according to the guidelines mentioned above, predicted the strength of the member well, but the failure mode did not satisfy the design assumption because of unexpected damage to the GFRP plate due to the fixing method, washered steel nail.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.582-587
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• 2020

Recently, disasters caused by extreme weather and the damage caused by them are increasing worldwide. The interest in disasters, such as earthquakes, typhoons, and ground subsidence, is increasing in Korea. Korea has enacted a special law based on disaster management, and has built monitoring systems for individual facility units by building precision sensors and related systems to measure the displacement status of long bridges and high-rise composite buildings. On the other hand, the application of a real-time monitoring system is insufficient for slopes, open-pit mines, small and medium structures due to weather, measurement methods, cost, and constant monitoring difficulties. In this study, the displacement monitoring method using the total station was studied and the applicability was suggested through the experiment. Through the research, the concept and operation flow of a monitoring system that can measure the displacement of the terrain or the structure using the total station was presented. The monitoring system allows the user to select the location and operation method of the equipment so that the equipment can be installed according to the site situation, and set the number of observations, the period, and the observation range of the object. Using the experiment on the monitoring system, the station was monitored with precision within 5mm, and it was suggested that the displacement of the object can be monitored using the total station. Further research will be needed to assess the applicability of monitoring to real slopes and structures.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.405-411
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• 2016

Seoul city is publishing new plans to increase modal share rate of bicycle every year, such as, maintaining bicycle related facilities. But bicycle's modal share rate in Seoul stayed same for the last decade and people are still facing difficulties using bicycle related facilities. These problems are causing bicycle usage as connecting transportation of public transit to decrease. This study looked at the high bicycle modal countries, such as, Netherlands, Germany and Japan to find applicable solutions by analyzing cases and comparing them with cases of highly populated subway station of Sindorim in Seoul. For example, in Germany and Netherlands there is bicycle-parking system to help bikers to access subway easier, in Japan there is underground bicycle parking tower to safely keep high volume of bicycles with in small space. For Seoul city to increase its modal share rate, they should look at problems from users' prospective and solve it by fixing it and improving the services, not by making more facilities.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.791-796
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• 2007

As large-scale buildings, skyscrapers, and multi-purpose buildings recently increase in numbers dramatically, the internal space of such buildings becomes more and more large and complicated accordingly. Since such structures usually accommodate a number of random people, the potential possibilities of disastrous tragedies are high, and the rates of injury and physical damage caused by the complicated system of the building also increase as well. However, most of the shelter designs of the existing buildings are based on the specifications according to the assigned laws and involved regulations. In this case, only general criteria are referred to regardless of the characteristics of each structure while other disaster-related features are not taken into consideration sufficiently. Since any actual fire may cause a terrible calamity, in such plans, shelter inducement can be neither safe nor effective. Thus, this study examines and analyzes currently run disaster prevention systems and shelter inducement facilities with COEX Mall as its subject, and analyzes the responding system to each situation based on the fire scenarios by means of As-Is Model. Through this analysis, presented are the measures to solve the problems of current disaster prevention systems and to improve shelter inducement methods effectively.

• Journal of the Korean GEO-environmental Society
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• v.21 no.7
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• pp.5-16
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• 2020

Currently, the seismic design standards have been strengthened due to the occurrence of the Gyeongju and Pohang earthquake, and seismic performance evaluation of existing facilities is being conducted. It aims to secure a seismic performance effect during earthquakes by improving the micro-pile method, which can be constructed in limited confined places while minimizing damage to existing facilities. The improvement method is to construct all the piles in the square-tray-type plate on the top of the pile by constructing the slope pile in the form of an umbrella around the vertical pile, the main pillar. In this paper, the numerical analysis was performed to analyze the horizontal displacement behavior of an umbrella-type micropile for various real-measurement seismic waves in sandy soil. As a result of numerical analysis, the softer the ground, the better the effect of horizontal resistance of umbrella-type micropile. The horizontal displacement reduction effect was pronounced when the embedded depth was 15 m or more at the same ground strength, and it was found to be effective in earthquakes if it was settled on the ground with an N value of 30 or more. The embedded depth and horizontal displacement suppression effect of the micropile was proportional. Generally, the weaker the ground, the greater the displacement suppression effect. Umbrella-type micropile had a composite resistance effect in which the vertical pile resists the moment and inclined pile resists the axial force.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.5
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• pp.1-9
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• 2018

The purpose of this study was to identify differences of perceptions for gardens and parks between experts and the general public concerning several aspects including scope, scale, publicity, artistic and scientific nature, main materials, practicality and aesthetics, executive and management systems as well as legal understanding of garden and park. The properties of garden and park were derived through literature research, and the concept, similarity, and difference of gardens and the parks were recognized by the experts and the public viewpoint was clarified by questionnaire. As for the difference in the scope of the gardens and the parks, the expert group recognized it more widely than the general public. In general, the space recognized as a garden was the rooftop green space, and urban forests were recognized as a park. In addition, the general public recognized urban forests as gardens the same as they recognized parks, and the distinction was unclear. In the expert group, the perception that gardens were small and the parks were large was more prevalent. It was generally recognized that gardens were private spaces and the parks were public spaces. In the expert group, the gardens were more personal and the parks were more apparent to the public. In the general population, functional and scientific aspects rather than artistic creativity in both gardens and parks. In addition, both the general public and experts found that parks are more complex than gardens. The garden was centered on plant material, and the park was recognized as a center where the sculptural facilities were centered, or the plant material and the sculptural facilities were properly balanced. To the experts the view of the gardens was positive. Expert groups emphasized the aesthetics of the garden, and the parks were more practical, and the general population showed similar perceptions of utility and aesthetics when comparing gardens and parks. In addition, the utility of gardens in the general publics is more emphasized than the aesthetics of the park. Regarding the executive system the park was recognized as the public sector, and the difference was larger in the expert group. As for the management system, both experts and the general public perceive the management of the park or the garden to be carried out by the supporting organization, and it is necessary to discuss the diversification of the management subject. It is found that there is a certain difference in recognition with the mixture of concepts, and there is still a big difference in legal system and perception.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.150-160
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• 2011

IT convergence and integration technology aims to create new synergies by combining IT related technology and performance. This study conducted a basic research for combining construction and IT technology to create new synergies. Specifically, the purpose of this study is to combine USN and GIS technology and then apply it to urban facilities management. For this, we have developed the USN hardware, tested propagation communications, and made the GIS Algorithm and a system. Existing sensor node allocation method is mostly to install in a random way or with in-situ survey, but the problem with this method is contradictory to cost effectiveness and efficiency. To solve this problem, we developed a new method for sensor allocation. Using this method, the USN technology could be applied in the range of city unit. This technology can be applied to the ubiquitous urban development such as U-City and Smart City.

• Korean Journal of Construction Engineering and Management
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• v.21 no.2
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• pp.22-29
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• 2020

Among many fire-related laws and standards such as fire protection, fire doors are important facilities that play a role in preventing the spread of fire and smoke in the event of fire, thereby minimizing human casualties. Accordingly, the standards for performance required by applicable laws and regulations and related enforcement rules and notices have been continuously raised and the corresponding performance must be secured. However, due to the shortcomings of the relevant laws and systems, the test results of the fire doors confirmed that there was a risk of passing products. In this study, the criteria for fire-related performance were analyzed, and the performance required by other laws, in addition to simple fire protection, was identified, the criteria were organized, and the complex performance required was clearly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.1-8
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• 2017

The purpose of this study is to propose a cache structure for processing large-volume building information modeling (BIM) geometry data,whereit is difficult to allocate physical memory. As the number of BIM orders has increased in the public sector, it is becoming more common to visualize and calculate large-volume BIM geometry data. Design and review collaboration can require a lot of time to download large-volume BIM data through the network. If the BIM data exceeds the physical free-memory limit, visualization and geometry computation cannot be possible. In order to utilize large amounts of BIM data on insufficient physical memory or a low-bandwidth network, it is advantageous to cache only the data necessary for BIM geometry rendering and calculation time. Thisstudy proposes acache structure for efficiently rendering and calculating large-volume BIM geometry data where it is difficult to allocate enough physical memory.