• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.81-87
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• 2010

As enormous construction projects of land development are carried out around Korea, useful construction materials are needed to perform the construction projects. However, there are no more enough of fill and reclamation materials in our country. That is why the coal ash is expected to be utilized as an alternative material. Since the coal ash has the characteristics of a pozzolan and a selfhardening material, it is adjudged that coal ash has a great possibility to be used as a fill and reclamation material. In this study, grain size analysis, Atterberg limit test, and specific gravity test were performed to examine the physical characteristics of the coal ash about a self-hardening material before utilizing the coal ash in the construction. Compaction test, unconfined compression test were conducted to investigate the engineering characteristics according to mixture ratios of fly ash and bottom ash. As a result of the tests, it was confirmed that the mixing ratio 1:1 of fly ash and bottom ash is the most effective to use as a fill and reclamation material. If the mixture of coal ash is used as a backfill material with light weight around structure, it is expected to play a significant role in reducing earth pressure on the back of the structure. As described above, the coal ash should be considered as an alternative material of fill and reclamation materials since the result of the tests indicates that the coal ash is suitable to a useful material on the construction design.

• 한국건설관리학회논문집
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• 제5권5호
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• pp.109-116
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• 2004

우리나라 건설기업들은 최근 경제 위기를 겪으면서 대외적으로 커다란 환경변화의 요구에 직면해 왔다. 내$\cdot$외부의 환경변화는 기업의 경영조직에 많은 영향을 끼치고 이러한 경영조직은 기업의 경영성과와 밀접한 관계를 가지고 있다. 이에 대응하여 건설기업들은 환경변화에 적응하고 경영성과를 증진시키기 위한 일환으로 기업 내 구조조정, 경영혁신, 조직개선 등의 명목으로 기업경영조직의 개선 노력을 기울이고 있다. 즉, 기업성장에 도움이 되지 않는 조직 구조는 오히려 기업에 역효과로 작용하게 되므로 기업은 가치를 높일 수 있는 효율적인 조직구조를 갖추어야 한다. 또한 향후 환경변화에 유연하게 대처할 수 있는 경영조직의 개발과 구축은 기업의 경영성과를 증대할 수 있는 중요한 기반이 될 수 있다. 이에 본 연구에서는 설문 및 자료조사를 통하여 기업의 조직구조를 분석하고 이를 유형화 한 후 OLC측면의 조직구조 형태분석으로 기업발전단계에 적정한 조직을 설계할 수 있는 모형을 제시하고자 한다.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.103-110
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• 2022

In the era of the 4th Industrial Revolution, smart technology being considered to improve productivity breakthroughs is in the spotlight as a means to replace traditional construction technology in the construction industry. However, various problems are occurring in construction sites using smart technology and causing negative impacts on construction projects. Therefore, the objective of this study is to identify risk factors that occur when smart technologies are used in construction projects. To achieve this purpose, this study investigated the difficulties at construction projects using smart technology, and risk factors were derived based on site surveys and literature. The risk factors were measured by experts, and then a total of 19 risk factors was derived by exploratory factor analysis. As a result, risks were classified as 5 factors, the institutional factor is the most difficult response, and the government needs anticipative system improvement and a long-term plan. The research findings provide practical implications for construction experts trying to apply smart technology in construction sites and construction policy-makers to revitalize smart technology.

• 지질공학
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• 제33권2호
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• pp.307-322
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• 2023

대형 댐 및 대심도 지하공간 개발에서 많이 시행되는 암반 그라우팅은 기초지반의 누수를 방지하여 안정성을 향상시키고 추가적인 재해를 방지하기 위해 사용되는 중요한 공종 중 하나이다. 대부분의 암반 그라우팅은 수리지질 및 암반공학적 지수들(RQD, Q-value, GSI, Js, Ap, Lu, SPI, and K)에 의해 영향을 받는다. 따라서, 안전하고 적절한 그라우팅 설계 및 시공을 위해서는 지질학자들의 정확한 기초 암반의 분석과 적절한 그라우팅 계획 수립이 필요하다. 해외의 경우 기초 암반의 수리지질 및 암반공학적 특성 분석과 그라우트 주입량(grout take, GT) 예측에 대한 연구가 활발히 이루어지고 있으며, 주로 댐의 기초지반 분야에서 많은 연구가 수행되었다. 하지만, 국내의 경우 그라우트 주입재료 및 시공관리 기법에 대한 연구는 많이 수행되었으나 암반의 수리지질 및 암반공학적 특성을 고려한 암반 그라우팅 공법에 대한 연구는 미흡한 실정이다. 이에 본 리뷰에서는 암반 그라우팅 계획시 중요한 수리지질 및 암반공학적 지수들(RQD, Q-value, GSI, Js, Ap, Lu, SPI, and K)과 그라우트 주입량의 상관성 분석을 진행한 해외 연구 사례를 파악하고 국내의 암반 그라우팅 관련 연구의 발전방향을 제시하였다.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.24.1-24.15
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• 2023

Background: The construction workers are vulnerable to fatigue due to high physical workload. This study aimed to investigate the relationship between overwork and heart rate in construction workers and propose a scheme to prevent overwork in advance. Methods: We measured the heart rates of construction workers at a construction site of a residential and commercial complex in Seoul from August to October 2021 and develop an index that monitors overwork in real-time. A total of 66 Korean workers participated in the study, wearing real-time heart rate monitoring equipment. The relative heart rate (RHR) was calculated using the minimum and maximum heart rates, and the maximum acceptable working time (MAWT) was estimated using RHR to calculate the workload. The overwork index (OI) was defined as the cumulative workload evaluated with the MAWT. An appropriate scenario line (PSL) was set as an index that can be compared to the OI to evaluate the degree of overwork in real-time. The excess overwork index (EOI) was evaluated in real-time during work performance using the difference between the OI and the PSL. The EOI value was used to perform receiver operating characteristic (ROC) curve analysis to find the optimal cut-off value for classification of overwork state. Results: Of the 60 participants analyzed, 28 (46.7%) were classified as the overwork group based on their RHR. ROC curve analysis showed that the EOI was a good predictor of overwork, with an area under the curve of 0.824. The optimal cut-off values ranged from 21.8% to 24.0% depending on the method used to determine the cut-off point. Conclusion: The EOI showed promising results as a predictive tool to assess overwork in real-time using heart rate monitoring and calculation through MAWT. Further research is needed to assess physical workload accurately and determine cut-off values across industries.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.277-283
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• 2022

• 한국지반신소재학회논문집
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• 제7권2호
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• pp.7-13
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• 2008

토목공사를 수행함에 있어 토목섬유가 적용된 이후 토목섬유의 손상에 대하여 많은 관심이 되어왔다. 토목용 섬유제품인 지오텍스타일은 주변 환경조건에 노출되는 고분자 재료로서 분리, 보강, 여과, 배수 등의 기능을 가지며 현재 제방공사, 해안 하천의 호안공사, 간척공사 또는 도로, 철도 노상 안정 등의 분야에 광범위하게 이용되고 있다. 본 연구는 토목섬유매트의 현장 적용시 설계방법을 분석하였고, 설계시 고려되는 인장, 파열, 꿰뚫림, 인열강도의 관계와 더불어 인장강도와 봉합강도의 상관성에 대하여 평가하였다. 또한, 토목섬유매트 적용시 유효봉합율과 시험방법의 적정성, 경제성 등이 고려된 시공방법론 등을 제시하였다.

• 한국건설순환자원학회논문집
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• 제2권2호
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• pp.93-100
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• 2006

Building materials are trending toward environmental materials nowadays and the market share of those is growing. So those researches and developments for environmental property are proceeding now. The main properties of environmental products are far infrared emission, negative ion emission, electro magnetic wave shielding, and anti fungus, these products are used with shape of mortar, and spray on the finish material. But There are not much researches for the concrete, main material in construction field, with those functional properties. So in this research we evaluated slump, compressive strength and air content as basic properties for concrete using functional materials of sericite, wood pattern sand stone, carbon black and nanometric silver solution and functional properties like far infrared emission, negative ion emission, electro magnetic wave shielding, and anti fungus. The results were as follows. The most useful material in the functional materials was carbon black. Sericite and nanometric silver solution had a little effect on functional property, so it was difficult to apply to concrete, and wood pattern sand stone had a high functional property but low compressive strength, can be applied to a factory product. Anti fungus of the concrete using nanometric silver solution was not clear but if those specimens were aged in $CO_2$ gas for a long time it might apparent.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권2호
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• pp.10-16
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• 2017

Recently, the gap between demand and supply of natural aggregate has increased owing to the depletion of aggregate sources. Therefore, policy support is necessary for the stable supply of aggregate resources. Public and construction works experience problems when they do not receive a steady supply of aggregate. Further, instabilities in aggregate supply lead to increases in aggregate prices, and consequently construction costs. As a result, the likelihood of poor construction using low-grade aggregate increases. It is therefore crucial to put measures in place that deal with these issues. This study aims to reduce the load imposed by aggregate use on the environment by recycling soil dredged from sewage ducts to reduce the gap between supply and demand of fine aggregate. The dredged soil is assessed using an applicability test for quality characteristics and solidification with basic properties. This study aims to secure the safety of dredging soil and solidified objects through interior physical and chemical analyses and to utilize it as a base material for concrete solidification in the future.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.896-901
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• 2009

A Soil Nail is a structural element which provides load-transfer to the ground in excavation reinforcement applications. The nail may simply consist of a steel tendon, but most commonly the tendon is encapsulated in a cement grouted body to provide corrosion protection and improved load- transfer to the ground. For temporary excavation support in a congested urban area, the steel bar of Soil Nails should be removed to get permission of the private land to install Soil Nails. Several removable nail systems were developed and evaluated by pull-out load tests. The Soil Nail pull-out tests were performed on five nails installed in soft and hard rock at a 00 housing-redevelopment area in seoul. Two nails are plastic socket type and two are complex socket type mixed steel and plastic. The nail was 0.1mm in diameter, 4m long. In this study verification tests, and steel bar removing tests of plastic socket type nails and complex socket type nails were performed and presented.