• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.971-976
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• 2007

In the U.S., utility damages or utility delay caused by conflicts during the underground utility relocation is one of the weighty problem in the construction industry. Also, in domestic case, delay and additional cost caused by underground utility(i.e, electricity, communication, gas, water supply and sewerage) relocation has been happened so that there is an increase of claims for responsibility between owners and contractors. However, there is insufficient survey for the recent circumstance of additional cost for delay and design changes caused by utility relocation and shortage of enough research for solving and analyzing of causes and their ripple effect. This research presents a result of the study about the best practices of FHWA(Federal Highway Administration), SHAs(State Highway Agencies) and the utility companies managing utility relocation. Also, it presents the basic concept of SUE(Subsurface Utility Engineering), the most reliable tool of FHWA presented, and investigates the developing status about SUE in Korea. At the end of this paper, this research proposes a practical and more applicable study about the efficient utility relocation focusing on local industry.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.158-159
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• 2005

The paper presents a method for location of subsurface UXOs. The approach utilities gradient interpretation techniques (analytic signal, horizontal gradient and Euler methods) to locate the objects. Then, linear least-squares technique, we obtain the magnetization location of the sources. We demonstrate the practical utility of the method using marine magnetic field data.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.638-642
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• 2005

This paper presents incentive application strategies and delay prevention strategies as schematic approaches to improve time performance of highway construction contracts. This research recognizes the importance of improving time performance during highway construction. Strategic solutions of the most core issues on time performance incentive contracting are identified. The suggested incentive application strategies develop criteria for applying time classification to projects, for assigning project time classifications to contractors and designers, and for determining appropriate incentive values in A (cost) + B (time cost) and other performance incentive contracts. The suggested delay prevention strategies develop criteria for determining the appropriate subsurface utility engineering (SUE) level and to develop best practices for avoiding utility relocation delays. A schematic approach for each strategy is developed. This paper also introduces current incentive contracting practices in Florida. The researchers obtained the information from experienced persons in the highway construction industry, including key highway contractors, designers, and Department of Transportation (DOT) and Federal Highway Administration (FHWA) personnel. The major focus of this research is to develop strategies and suggest approaches to improve time performance of highway construction contracts. For future study, practical tools to facilitate implementation of the suggested strategies should be developed, so that the criteria, implementation processes, and best practices developed may contribute to the current industry-wide effort to improve time performance.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.527-534
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• 2019

Although ground investigation had carried out prior to the construction, many problems have arisen during the civil-engineering works because of the presence of the unexpected underground utility lines or anomalies. In this study, a new geophysical exploration method was developed to solve those problems by improving and supplementing the existing methods. This new method was based on the difference of electrical resistance values between anomalies and surrounding ground medium. A theoretical expression was suggested to define the characteristics of the anomalies such as location, size and direction, by applying the electric field analysis. An inverse analysis algorithm was also developed to solve the theoretical expression using the measured electrical resistance values which were generated by the voltage flowing the subsurface medium. To verify the developed method, field applications were conducted at the sites under construction or planned. From the results of the field tests, it was found that not only the new method was more predictive than the existing methods, but its results were good agreed with the measured ones. Therefore, it is expected that application of the new exploration method reduces the unexpected accidents caused by the underground uncertainties during the underground construction works.

• Journal of Soil and Groundwater Environment
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• v.24 no.3
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• pp.13-23
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• 2019

The purpose of this study is to suggest conceptual models based on finite numerical method that can be used to assess contaminant transport through subsurface and estimate exposed concentration at contaminated site. This study tested various assumptions of the numerical models for contaminant transport in unsaturated and saturated zones to simulate the pathways to the human exposal point. For this purpose, models for seven possible scenarios of contaminant transport were simulated using the numerical code MODFLOW and MT3D. The simulation results that showed different peak concentrations and travel times were compared. In conclusion, the potential utility of the numerical models in the site specific risk analysis suggested as well as future research ramifications.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.161-166
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• 2006

Vertical gravity gradient measurement offers greater structural resolution and detectability than gravity alone. Practical difficulties of field measurement of vertical gravity gradient have raised questions of its accuracy and utility. But, modern automated gravimeter of $1\;{\mu}Gal$ sensitivity makes it easier to measure vertical gradient with required accuracy. It is particularly effective to engineering and environmental problems which target shallow subsurface structure. This paper attempts to apply the vertical gravity gradient technique to high resolution density mapping. The method was generally reviewed and numerical inverse modeling was executed for comparing with conventional gravity. And actual vertical gravity gradient data surveyed overt karstic cavity area at Muan was analysed and interpreted.

• Tunnel and Underground Space
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• v.27 no.6
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• pp.387-392
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• 2017

Recently, road cave-ins, also referred to as ground sinking, have become a problem in urban environments. Public utility facilities such as sewage pipelines, communications pipes, gas pipes, power cables, and other types of underground structures are installed below the roads. It was reported that cave-ins are caused by the aging and lack of proper maintenance of underground facilities, as well as by construction problems. A road cave-in is first initiated by the formation of cavities typically induced by the breakage of underground pipelines. The cavities then grow and reach the base of the pavement. The traffic load applied at the surface of the roads causes an abrupt plastic deformation. This type of accident can be considered as a type of disaster. A road cave-in can threaten both human safety and the economy. It may even result in the loss of human life. In the city of Seoul, efforts to prevent damage before cave-ins occur have been prioritized, through a method of discovering and repairing joints through the 3D GPR survey.