• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.567-575
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• 2018

This study examined a pile foundation using a spiral pile. To maintain the structural safely, a foundation for connecting the ground and the ground structure is needed. On the other hand, noise and vibration, etc. cause problems when constructing a foundation on adjacent structures or urban areas. A study of the spiral foundation of a new shape with low vibration and noise was carried out to solve these problems. A study of pile foundations was carried out on a scaled model test and compared with the results of Meyerhof's bearing capacity theory. The scaled model test results showed that the bearing capacity increases with increasing pitch angle and length of the spiral pile. To verify the measured bearing capacity in a test with theoretical results, the bearing capacity of the actual spiral pile and scaled model pile were examined and compared. The ultimate bearing capacity of the spiral pile can be increased by increasing the foundation length and pitch angle. This study complements existing foundation construction problems and contributes to a better effect and safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.317-325
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• 2020

The development of a technique that can monitor the cracks, which is one of the typical types of damage, is necessary to secure the structural safety of elastically restrained cantilever-type beams with a tip mass that is used widely in infrastructure. Impedance techniques have been actively researched to detect cracks, and the cracks were estimated mainly by experimentally investigating the relationship between the crack and impedance signal. This study examined the correlation between the change in the impedance signals due to the crack, and the natural frequency obtained analytically. After updating the analysis model for the intact beam, the impedance signal was measured while gradually inflicting cracks in the cantilever-type beam, and the damage index was obtained. The results were compared with the natural frequencies calculated from the updated analysis model to investigate the correlation. A close correlation was observed between the experimentally obtained impedance damage index, and the analytically calculated natural frequency. Using this correlation, the structural characteristics could be evaluated more accurately from the damage estimation results, and the behavior of the structure could be predicted effectively using the analysis model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.501-509
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• 2020

Earthwork in the construction field is a core process of construction, and it is used in almost all processes and is connected to the safety of the structure directly. Therefore, it is essential to analyze and confirm the road tamping through a plate bearing test and a field density test. The current analog measurement methods for road tamping measurement is difficult to check in real-time, accurate location information, time information, and the history management of workers in the field. Therefore, IoT (Internet of Things)-based DCPT (Dynamic Cone Penetration Test) was developed for a smart construction environment with a solution to the problem. The Smart DCPT system operated in a smartphone environment is IoT-based. The Smart DCPT system can apply various applications and has advantages of flexibility, low cost, and high efficiency. The IoT-based DCPT records the digital road tamping information, location information, time information, and worker information per measurement count. In addition, the various information is transmitted in real-time to the management center through a smartphone. This system is expected to contribute to the management of the construction process.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.11-17
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• 2011

This study focused on the regulations and support system of green rooftop landscaping between Korea and China. Our research found out regulations and support system to review the supplement point to understand the present state of green rooftop landscaping in the two countries. We aimed to provide basic legal information for the development of green rooftop landscaping regulations. Also, a management plan guide and after-evaluation guide were suggested. First, roof load safety is the foremost factor for the structure of green rooftop landscaping. It includes not only considering the weight of construction materials, but also accurately calculating weight of rain, snow and the rooftop's capacity for people when the rooftop is designed. Second, the appropriate waterproof and root material should be selected basing on climatic conditions. Third, a maintenance and management plan needs to be established to regularly check the plant, facilities, soil and to maintain them. Fourth, the criteria of quality inspection are waterproof and root resistant material, and the growth and development of plants. Waterproof and root resistant materials are a very important part of rooftop greening, so they must be strictly inspected after construction. Fifth, the support system of rooftop greening should be continuously improved. The choice of the object and the amount of support should be strictly stipulated so that the construction of rooftop is promoted when volunteers do rooftop greening.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.6 no.4
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• pp.153-171
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• 2011

The welfare system and the direction of the welfare policy have been unable to escape greatly from the frame of the past against the facts that the external environments of the national economy of the world including Korea have been changing in quick and rapid speed. Such results have caused the issues related with the welfare, economy and society ended in the ideological collision in connection with the goals of the policy, the right agreement between the policies lacked, and the intervention and conflict between the interest group concerning the policy continued. Social policy of Korea in the past had the level of complementing the parts which could not be solved through the growth. Employment creation had been achieved continuously backed up by the high rate of growth. And the low aging level, the young population structure, and the high rate of childbirth had been the structures that made such achievement possible. New economic, social and welfare environment at home and abroad has been requesting new change in welfare policy. Goal of the economic and social policy is to construct the safe economic and social system. And what has been requested has been the formation of the economic and social policy orienting the welfare nation in form of social investment and welfare expansion. Also the direction in strengthening the welfare system of Korea shall have the balance between the protection and activation strength with the necessity of converting to the prevention welfare from the post welfare. Also the public part, market, the 3rd sector and the share of the role of an individual shall be achieved. And what is needed is the achievement of the transfer from the paradigm of residual welfare to the universal welfare. And such improvements of the welfare system will be able to elevate the possible continuity of the system in long term basis through the improvement of the welfare system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.705-713
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• 2016

For the soft ground construction, the factors not considered in the design stage occurs in the construction stage so that they cause the increase of the construction cost due to the structural stability and the design change. The subject of the study is the construction section of the industrial complex access road made in the Ochang region of Chungcheongbuk-do. The study is concerned with selecting the soft ground handling method such as the replacement method using rock debris and the surcharge reflecting the service load as the soft ground handling measure and analyzing the effect of reducing the construction cost with the stability of structures and the reduction of the construction period. The soft ground in the study section consists of sandy and cohesive soil and is 2.4m to 5.5m deep. It is distributed unevenly between the 1.5m to 5.9m stratums under the ground surface. Settlement is not serious, but the future uneven settlement and difference are expected so that the future settlement behavior is estimated by analyzing the site measurement results after the soft ground treatment. Moreover, in consideration of the regional characteristics and economic efficiency, soil with good quality is replaced with rock debris as the replacement material so that 29% of the construction cost is reduced due to the increase of stability and the reduction of duration. If the estimation of the dispersion of the pore water pressure within the dam body and the change of the underground water level and the relation of the actually measured soft ground with consolidation is studied further on the basis of the study, it is expected that the behavior of the soft ground will be correctly estimated in various site conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4A
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• pp.269-278
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• 2011

Recently, methods on minimizing environmental effect caused from human-made goods have been studied in various research fields. Such issue has been also spotlighted into the civil engineering field; however, application of environmental performance assessment on civil structures is very complicated, since they handles vast ranges of materials and has comparatively long life span with various construction stages. Thus, this study intended to apply environmental performance assessment into an ordinary type of steel box girder bridge, using most popular Life cycle assessment (LCA) procedures, which are called Survey-based method and Indirect method. For better comparison of two methods, greenhouse effect of the example bridge is considered. As result of analysis, total $CO_2$ emission is evaluated as 241.27 ton with Survey-based method while it is evaluated as 221.03 ton with Indirect method. It is also revealed that most $CO_2$ is generated from the process of manufacturing and producing construction materials. Such result indicates that the efficient design which secures certain level of structural safety with minimized input materials. It is considered that the specific LCA on civil structure performed in this study could be utilized to other civil structures for reasonable environmental performance assessment.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.117-131
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• 2009

When most drivers take to the freeway, they don't necessarily pay attention to the geometric design. They expect proper design by depending on their own senses and recognition. When they evaluate the features of traveling on the freeway, they can think differently than engineers. The design needs to predict the exact speed of the driver to satisfy the driver's expectation, safety, pleasure and so on. This study categorized the factors influencing the speed of six freeways considering geometric and operational features to make a prediction model of speed. The model used multiple regression with these factors and produced statically appropriate results. This study utilized the principle component analysis and the quantification II analysis based on the image data of the satisfaction of the traveling environment collected through individual interviews. As a result, this study found the factors of satisfaction in a traveling environment. It made a satisfaction model of the traveling environment on freeways considering the change of driver's actual recognition and societal recognition using structural equations and the quantification II theory. Through the model made in this study, This model can present not only qualitative factors like satisfaction of traveling environment on freeways, but also the quantitative elements like speed. What is important is the evaluation of features of traveling on freeways reflected in the recognition and traffic environment felt by drivers.

• Archives of design research
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• v.18 no.1 s.59
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• pp.175-184
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• 2005

With the rapid progress of the aging society in Korea, the silver generation is emerging as another class of users in the new population structure. This is a social issue to be dealt with, and the effect of such a change is being observed dearly in the design area. In addition, there are increasing demands for consideration of minor groups of users including the elderly, the disabled, the left-handed, children and pregnant women and nursing mothers, who have been treated as the weak. Such a human-centered idea may be the manifestation of the recovery of humanity and the self-realization of human beings through experiences and reflections of the industrial society of the past. The present study examined the tendency of design standardization centering on universal design, which has emerged in response to user-centered social needs, and suggested general considerations for the necessity of introducing such standards. These days the meanings of standardization are not limited to quality, performance, safety and economic aspect. Standardization is required to consider the diversity and the welfare of human beings. In addition, one of the important functions of standardization is to provide designers with important clues and guidelines for designing. In reality, however, standardization has been rejected by the circle of design for the reason that it deters free creation, so research on the introduction of standardization has been at standstill. As ISO/IEC Guide71 was published in November 2001, based on which, the Korea Standards Association established KS A ISO/IEC Guide71 without changing its contents. In companies' manufacturing activities, the progress of standardization in connection to universal design is growing more important. However, usefulness and interchangeability for the absolute majority resulting from standardization are incomparable. Lastly, the realization of universal design requires human-centered design mind, based on users' experiences and needs, the characteristics of the human bodies and inconvenient elements rather than standards for the sake of standardization.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.55-68
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• 2008

At present underground structures such as road tunnels, railway tunnels, underground petroleum storages and radioactive waste storages are being constructed in numerous places in Korea. For the construction of underground structrues, it should be accounted for natural factors (geology, hydrogeology, soil, vegetation, topography and drainage patterns) and human-social factors (land use, urbanization, population, culture and transportation). Especially, hydrogeology should be regarded as an important factor for evaluating the safety of underground structures and their impact to groundwater system around the structures. This study aimed to recognize hydrogeological characteristics of shallow formations in the area from Dongrae crossway to Seo-Dong where 45 boreholes were drilled for the construction of Line-3 subway in Busan Megacity. Slug tests for unsaturated and saturated zones were conducted on 30 boreholes in the study area. From the result of the slug tests, it was identified that average zonal hydraulic conductivity in the unsaturated zone was higher than that in the saturated zone. Besides, the slug test result in the saturated zones may reflect hydraulic properties of the upper most part of the saturated zones.