• Journal of the Korean Geophysical Society
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• v.6 no.1
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• pp.13-23
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• 2003

Dipole-dipole resistivity and ground penetrating radar(GPR) surveys were performed on an abandoned landfill site filled with asbestos containing material. The main purpose of the study was to estimate spatial extension and volume of the landfill for evaluting the cost for developing appropriate remedial alternatives. Assuming that the bedrock is within 10 m depth, dipole spacings of 2, 2.5 and 5m were set for six survey lines for resistivity measurements. For More detailed information, GPR suvey using 225 Mhz antenna was carried out for twelve survey lines for the shallower information. DC resistivity structures showed few tens ~ hundreds ohm-m for the landfill or alluvial laver, and 1,000~ 5,000 ohm-m for the bedrock. The depth to bedrock is found out to be approximately 5m. GPR survey results represented very clear reflection and/or diffraction events from the boundaries as well as from the blocky construction wastes. With high-resolution GPR survey, depth of the bedrock was resolved up to 2m, which in turn, could be a good indicator for estimating the volume of the landfill. Those depths of bedrock were confirmed by backhoe excavation data for 13 sites. The total area and volume of the landfill were to be approximately 3,953 .$m^2$ and 4,033 $m^3$, respectively.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.393-400
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• 2011

The needs for high strength structural materials have recently increased, because construction and cost efficiencies are demanded by the costumers. But, the use of high strength reinforcing bars requires longer development and splice lengths compared to normal strength bars. This restriction may cause reduction in construction efficiency and require more complicated details. The purpose of this paper is to evaluate the bond strength on the rib shape of reinforcing bars to decrease development and splice lengths of high strength reinforcements. Total of 5 simple beam specimens were tested, and the main test variable was a rib shape of reinforcing bars. Test data was analyzed in the viewpoint of bond strength, load-deflection relationship, and crack pattern. Test results indicated that the bond strength of high relative rib area reinforcing bars increased up to 11% compared to normal strength reinforcements. And the improved rib shape reinforcements, which were formed with high and low height rib, increased the bond strength up to 23% even though the relative rib area was same as the high relative rib area reinforcements. Serviceability performances such as deflection number of cracking, and maximum crack width were similar in all specimens, so it is safe to conclude that the improved rib shape reinforcements can be applied to the structural members.

• Korean Journal of Heritage: History & Science
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• v.47 no.3
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• pp.4-23
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• 2014

Seokjojeon Hall is the Neoclassic style building situated in Deoksugung Palace, which was proposed by John McLeavy Brown who was a chief commissioner of the Daehan Empire and designed by John Reginald Hardings in 1897. Construction of the Seokjojeon Hall began in 1900 and completed in 1910 at the total cost of one million won. Decorating and furnishing of the interior was designed by Lovell and all the furniture of Seokjojeon Hall had been purchased from Maple&Co. The Maple&Co was the supplier of luxury furnitures and decorating items for luxurious residentials, hotels, embassies and the palaces and its headquarter was located in London. Ready-made furnitures were purchased as shown in the Maple's catalog. The designs and styles of the west were applied to Seokjojeon Hall. That is one of the aspects showing Daehan Imperial underwent a period of Westernization.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.31-54
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• 2022

This study is to suggest the direction of the spatial change of the university library based on the trend of the spatial change in the university libraries and a survey on the perception of the librarians. For this purpose, the characteristics of the spatial change of the university libraries from 2000 to 2020 were analyzed, and the problems of the spatial change of the university libraries were identified through a survey. As a result of the survey, there was a total of 99 spatial changes in the university libraries nationwide over the past 20 years, including new construction, extension and remodeling. In recent years, it was found that due to the university's budget tightening policy, the university libraries focus on remodeling rather than new construction or extension. The characteristics of the spatial change were analyzed as follows. First, the resting areas have been expanded in the libraries. Second, The libraries are in pursuit of pleasant and comfortable atmosphere. Third, the libraries aim to establish an innovative and creative space. All these changes have been made in order to accommodate the requests of users and increase the number of users. It was also found that spatial change has advantages in these two points: providing various spaces and increasing the number of library visitors. On the other hand, spatial change has the problems such as the increased cost of maintaining the facility and the lack of management manpower. Additionally, a few more problems of spatial change are pointed out: first, spatial change only reflects the trend of the times without making a big change in the services and the actual value of the university library. Second, it has made university libraries standardized losing each library's own characteristics. This study suggests that the spatial change of the university library should secure the distinctiveness of the university library, accommodate various changes, and aim for the symbolism that can prove the value and existence of the university library.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.839-848
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• 2006

Korea has become the 5th country to own and operate the high speed railroad in 2004. However, there were many difficulties until Koreans enjoy the first bullet train service with the average hourly speed of 300km. The high speed railroad requires elevated quality standards differently from the traditional railways. In addition to the technical difficulties, the construction project itself was an unpleasant case with huge delays and cost overruns mainly due to the lack of experiences, deficiency of owner$^{\circ}{\O}$s role, and increase of public resistances triggered by environmental concerns. This paper analyzes the reasons for delays on this mega-project. With respect to the characteristics of the whole project level, it is very complicated/linear project, whose total length is around 412 km with the composition of various sections in the route of the railway which have basically different conditions. For that reason, the analysis is performed in both macro and micro level. First, macroscopic analysis is performed to find critical subdivisions in the railway route that induces the significant delay in the opening due date. Then, microscopic analysis is followed to quantify the causes and effects of delays focused on these critical subdivisions in more detailed way. Finally, this paper provides lessons learned from this project to avoid the decisive delays in performing the similar large-scaled projects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6C
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• pp.251-258
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• 2009

In this study, the optimum design conditions for embankment construction on soft clay layer improved by soil compaction pile (SCP) are discussed by comparing the practical design method to the reliability design which is based on the loss function and advanced first order second moment (AFOSM) method. The results are summarized as follows; 1) the relationship between safety factor and failure probability becomes heavy exponentially, failure probability decreases rapidly till 1% approximately until safety factor is smaller than 1.2 and after then, failure probability decrease gradually along the increase of the safety factor. The design safety factor of 1.2 may be the critical value that has been established on considering both relationships appropriately, 2) the safety factor of 1.15 at the minimum expected total cost is a little smaller than the design safety factor of 1.2 and the failure probability is about 1%, 3) the sensitivities of the ratio of stress share and the internal friction angle of sand is larger than the variables related the undrained shear strength of soft layer. This result means that the distribution characteristic of n and ${\phi}$ influences on the stability analysis considerably and they should be considered necessarily on stability analysis of embankment on soft layer improved by SCP, 4) new failure points of the input variables at the design safety factor of 1.2(below failure probability of 0.1~0.3%) is far 1~2 times of standard deviation from the initial design values of themselves.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.149-153
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• 2008

The pollutant capacity occurred before and after the development of a watershed should be quantitatively estimated and controlled for the minimization of water contamination. The Ministry of Environment suggested a guideline for the legal management of nonpoint source from 2006. However, the rational method for the determination of treatment capacity from nonpoint source proposed in the guideline has the problem in the field application because it does not reflect the project based cases and overestimates the pollutant load to be reduced. So, we perform the standard rainfall analysis by analytical probabilistic method for the estimation of an additional pollutant load occurred by a project and suggest a methodology for the estimation of contaminant capacity instead of a simple rational method. The suggested methodology in this study could determine the reasonable capacity and efficiency of a treatment facility through the estimation of pollutant load from nonpoint source and from this we can manage the watershed appropriately. We applied a suggested methodology to the projects of housing land development and a dam construction in the watersheds. When we determine the treatment capacity by a rational method without consideration of the types of projects we should treat the 90% of pollutant capacity occurred by the development and to do so, about 30% of the total cost for the development should be invested for the treatment facility. This requires too big cost and is not realistic. If we use the suggested method the target pollutant capacity to be reduced will be 10 to 30% of the capacity occurred by the development and about 5 to 10% of the total cost can be used. The control of nonpoint source must be performed for the water resources management. However it is not possible to treat the 90% of pollutant load occurred by the development. The proper pollutant capacity from nonpoint source should be estimated and controlled based on various project types and in reality, this is very important for the watershed management. Therefore the results of this study might be more reasonable than the rational method proposed in the Ministry of Environment.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.35-46
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• 2009

This paper presents an evaluation index for the supply levels of pedestrian facilities in residential area planning. The pedestrian facility supply levels reveal the quality of a residential area, and can be associated with the resident living standards and satisfaction, pedestrian safety levels, and the effectiveness of the construction cost. This research conducted multifaceted procedures for the index development, and these procedures start first by identifying dominant influencing factors on pedestrian travel demand by reviewing the final reports of site planning in more than eight already-completed residential development sites. Second, based on the Space Syntax model, which was initially developed in the UK by establishing statistical relationships among an integration index, population size (persons/day), and the total development area, this research formulated a set of pedestrian demand estimation models. Then these models were utilized in forming a pedestrian facility supply index by integrating the new models and their results with the available accepted practice in the residential planning sector. This was necessary because planners want to understand the total supply level of pedestrian facilities in a residential area during the initial design stage. Finally, to test the model validity in satisfying pedestrian satisfaction, the research included a resident satisfaction interview, and it was revealed that the evaluation index developed in this research could provide planners and engineers with more promising results. It is therefore anticipated that this research can be of service when designing pedestrian facilities in future residential area planning and design activities.

• Journal of Environmental Impact Assessment
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• v.27 no.3
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• pp.322-333
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• 2018

This study was carried out to measure atmospheric environmental improvement effect and estimate its social benefit of thermal power plants through Environmental Impact Assessment (EIA) for quantitative analysis about operational performances of EIA. In this study, 'EIA outcome' is defined as whether or not the system is implemented, therefore, environmental standard to be followed by each project and consultation contents were compared. In total 60 cases of thermal power plant construction projects that have been consulted over the past 10 years since 2010, major air pollutants have been significantly reduced after the implementation of EIA. The $PM_{10}$ reduced annual 3,745 tons, $NO_2$ by 74,569 tons, and $SO_2$ by 37,647 tons, which were estimated at approximately 240 billion won~5 trillion 967 billion won per year for social benefit. This means the total cost of power plant operations will be cut to 7 trillion 192 billion won~178 trillion 994 billion won over a 30-year period. The reduced amount of air pollutants emitted by energy generation facilities across the country is worth 50%, and its economic value is larger than the annual Current Health Expenditure in Korea. This is meant by the fact that all projects are subject to uniform criteria under the existing relevant regulation, but that each project plans are optimized according to the characteristics of target areas and projects through the process of EIA.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.47-55
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• 2005

Roads deeply affect the life of people and keep doing an important role to support economic growth of a country. According to the budget plan of the ministry of construction and transportation of Korea, 8.1 trillion won have been allotted for road investment in the year of 2002 which occupy 61% of the transportation infrastructure special account (13.3 trillion won) and 4.7% of the total national budget (1,740 trillion won). It is true that services generated from road investment such as mobility enhancement and increased accessibility have shown positive effects through shortened travel time and decreased vehicle operating cost. However, it is also notable that many negative effects are gradually being discussed and those are nowadays getting severer due to enhanced people interests about road construction, increased concerns on environment and active public involvement that were evoked by traffic accidents, air pollution & noise and destruction of environment. Road construction processes in Korea are normally governed by administrative sectors (suppliers) not by users. These processes ate very weak to accomodate user s needs and community concerns thus easy to fail finalizing a road project without hassles. A public hearing process is supposed to be held in the processes of detailed design step and the environmental impact analysis. However, it is not enough to grab user's needs and community concerns. Increased public involvement frequencies, optimized public involvement timing and enhanced depth of public involvement magnitude are suggested to improve the current poor public involvement schemes in road planning and design processes. The application of these recommended methods to the road planning and design processes may guarantee the change from the current supplier-oriented schemes to the new user-oriented one. Also, this study suggests to reset objectivity and clarity of road construction process, to make conciliation guidelines based on many practical cases that produced good results, to introduce public involvement techniques in a stepwise basis, and to foster the professionals via education and training programs.