• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.71-79
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• 2008

The underground conduit laid under different environments exhibits various behaviour according to the ground and external load as well as the loading time and conditions, so on. As the environmental conditions are usually different even within the same area, it is very difficult to correctly predict the stress conditions and behaviour of the underground conduit using currently available theoretical analysis. Especially, it is not yet satisfied in Korea for the evaluation of the underground conduit under the influence of the load of vehicles or unexpected loading conditions. Thus, in this study the assessment for the excavation depth and ground disturbance was carried out with a large box model test and numerical analysis. Numerical analysis was also performed for the assessment of dynamic loading conditions like railway load.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.77-85
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• 2010

Unconfined compressive strength tests were performed to evaluate curing characteristics of controlled low strength material(CLSM) made with coal ashes. It is found that unconfined compressive strength normalized by curing times, increases as decreasing the water contents of CLSM particularly during first three days. Dynamic cone penetrometer tests were also carried out to evaluate cost-effective CLSM lump strength characteristics with time. It takes around 10 days to reach target strength, 500kPa (penetration rate, 20mm/blow). Curing rate significantly decreases after 10 days elapsed regardless of CLSM formulation.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.33-46
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• 2013

Recently, the projects which are to increase the capacity of the flood control are being actively performed because of the abnormal climate changes throughout the country. In this study, the regression analysis was performed using both Kelvin model and the real settlement measured at the crest of the existing concrete face rockfill dam(CFRD) to estimate the long-term deformation behavior characteristics such as creep which occurs without additional load. In addition, the effects on changes in physical properties (E, G, K) of the dam construction materials by deformation characteristics of the dam were evaluated, and the reasonable stability analysis method of the dam was proposed to obtain the long-term stability considering the changes in physical properties induced by the long-term deformation behavior in case of heightening the existing dams.

• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.65-72
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• 2004

Within a country, owing to the restriction of aggregate which have been supplied to construction sites, applicability of byproducts such as the copper slag is expected to be more reasonable. In this study, on the basis of characteristics, grain distribution and environmental stability of copper slag, its engineering application was estimated as the vertical and horizontal drainage material. As a results of laboratory tests, it was shown that the permeability of the copper slag was similar to that of sands under vertical drainage condition. In addition, the copper slag showed higher critical hydraulic gradient than that of sand under upward vertical flow state. The copper slag has potential safety against piping and it that the copper slag is suitable for drainage and filter material.

• Journal of the Korean GEO-environmental Society
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• v.12 no.8
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• pp.25-31
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• 2011

In recent rainy seasons, severe rain storms have caused frequent reinforced retaining wall collapses and slope sliding which have lead to casualties. In this paper, investigating cases of reinforced retaining wall failure, the causes of cracks in reinforced retaining wall and slope sliding have been examined, and a finite element analysis considering the construction phase has been done to analyze the cause and characteristics of slope sliding. As a result, reinforced retaining wall displacement has increased due to heavy rain storms and the increase size has been shown to be large. From these results, it has been analyzed that pile driving can have an effect on the collapse of reinforced retaining walls.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.33-41
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• 2009

In the case of underground power utilities pipe such as circular pipe, the most difficult problem is low compaction efficiency of the bottom of pipe inducing the failure of utilities. To overcome this problem, various studies have been performed and one of these is CLSM (controlled low strength materials) accelerated flow ability. CLSM has already been stage of commercial use in the foreign countries led by power company. In this study, we estimated the behavior of flexible pipe with flowable backfill materials and sand to compare on the DB24 load. The results showed that the deformation of flexible pipe is affected by types of backfill materials. CLSM shows better behavior characteristics than compacting sand. But numerical and analytical results that peformed to compare to the field test results showed big gap with the field results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.55-64
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• 2008

Shotcrete have become a deterioration which was exposed to harmful environments. In this study, in order to evaluate the deterioration properties of shotcrete, visual examination, compressive strength, adhesive strength, microstructural analysis were investigated up to the 60th weeks of exposure. The attack solutions for test are sodium sulfate and hydrochloric acid solution with different concentrations, respectively. From the results, although the compressive strength of shotcrete specimens and the adhesive strength between specimens and rocks were high at the early immersion age, they rapidly dropped in the subsequent phases, especially in 5% sodium sulfate and pH1 hydrochloric acid solution. With continued exposure, various harmful ions penetrated into the shotcrete specimen, reacted with the cement hydrate, and generated expansion substances. It was verified that the shotcrete specimens suffered a serious deterioration by chemical attack.

• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.23-28
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• 2011

This study was conducted to investigate the adsorption characteristics of various surfactants including biosurfactant, SWA 1503, Triton X-100 and sodium dodecyl sulfate(SDS) on soil. The Freundlich adsorption isotherm equation was found to be the best to describe experimental results. The amount of adsorbed surfactant on soil increased as the content of clay increased. The results showed that surfactant was adsorbed mainly on the surface and the pores of soil since the surface area of clay was larger than that of sand. The amount of adsorbed surfactants on soil was as follows: Biosurfactant > SWA 1503 > Triton X-100 > SDS.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.134-136
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• 2015

본 논문은 일반 가정집, 아파트 및 사무실과 같은 좁은 생활공간에서 재배되는 다양한 식물 특성정보와 주변 환경 정보를 이용하여 재배 식물의 생장환경을 최적으로 지원할 수 있는 아두이노 플랫폼 기반의 식물 재배 지원 시스템을 제안한다. 제안하는 시스템은 스마트폰을 통해 사용자에게 식물 주변 환경 정보의 모니터링 및 간단한 습도 및 온도 원격제어 기능을 실시간 제공한다. 제안하는 시스템을 통해 사용자는 저렴한 비용으로 소중한 재배 식물의 안전한 생장을 유지할 수 있으며, 향후 다양한 환경 센서 및 상황 정보를 활용한 지능형 식물 관리 시스템 연구에 도움이 될 것으로 기대된다.

• Journal of the Society of Disaster Information
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• v.16 no.3
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• pp.513-525
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• 2020

Purpose: The purpose of this study is to analyze the characteristics of local factors affecting number of tuberculosis death by urban and rural areas. Method: The Partial Least Square(PLS) Regression analysis was used to solve the problem of multicollinearity and number of samples. Result: As a result of analysis, The number of tuberculosis deaths in urban and rural areas is about three times as large. As a result of analysis about Regional Characteristics Factor, In general, children, elderly people, and economically vulnerable populations are more likely to be exposed to tuberculosis. In differential results, it shows that environmental factors such as ultrafine dust and sulfur dioxide have a significant impact on the number of tuberculosis deaths in urban areas and social factors such as depression experience rate in rural areas. Conclusion: The Tuberculosis prevention and management policies that reflect the characteristics of urban and rural areas are needed in the future.