• 제목/요약/키워드: Civil & Environmental Engineering

검색결과 14,653건 처리시간 0.043초

Development and Application of an Energy Input-Output Table for an Energy Demand and Supply Activities Analysis

  • Pruitichaiwiboon, Phirada;Lee, Cheul-Kyu;Baek, Chun-Youl;Lee, Kun-Mo
    • Environmental Engineering Research
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    • 제16권1호
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    • pp.19-27
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    • 2011
  • This paper introduces an approach to identify the total energy consumption with subsequent $CO_2$ emissions, for both industrial and non-industrial sectors. Statistical data for 2005 were compiled in a national account system to construct an energy input-output table for investigating the influence between energy demand and supply activities. The methodological approach was applied to South Korea. Twelve types of energy and fifteen industrial and non-industrial sectors are formed as the compartments of the input-output table. The results provided quantitative details of the energy consumption and identified the significant contributions from each sector. An impact analysis on the $CO_2$ emissions for the demand side was also conducted for comparison with the supply side.

Probabilistic evaluation of chloride ingress process in concrete structures considering environmental characteristics

  • Taisen, Zhao;Yi, Zhang;Kefei, Li;Junjie, Wang
    • Structural Engineering and Mechanics
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    • 제84권6호
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    • pp.831-849
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    • 2022
  • One of the most prevalent causes of reinforced concrete (RC) structural deterioration is chloride-induced corrosion. This paper aims to provide a comprehensive insight into the environmental effect of RC's chloride ingress process. The first step is to investigate how relative humidity, temperature, and wind influence chloride ingress into concrete. The probability of initiation time of chloride-induced corrosion is predicted using a probabilistic model that considers these aspects. Parametric analysis is conducted on several factors impacting the corrosion process, including the depth of concrete cover, surface chloride concentration, relative humidity, and temperature to expose environmental features. According to the findings, environmental factors such as surface chloride concentration, relative humidity and temperature substantially impact on the time to corrosion initiation. The long- and short-distance impacts are also examined. The meteorological data from the National Meteorological Center of China are collected and used to analyze the environmental characteristics of the chloride ingress issue for structures along China's coastline. Finally, various recommendations are made for improving durability design against chloride attacks.

3D Earthwork BIM Design Process for a Road Project

  • Raza, Hassnain;Park, Sang-Il;Lee, Seung Soo;Tanoli, Waqas Arshad;Seo, Jongwon
    • 한국BIM학회 논문집
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    • 제7권2호
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    • pp.8-15
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    • 2017
  • Building Information modeling is playing an important role in transforming the construction industry. It helped the industry with better visualization, minimum design errors, and excellent planning of the construction activities. Time and cost saving can be effectively achieved by using BIM for any construction project. It improves information exchange between all the project stakeholders. However, the development of earthwork 3D BIM is still underway and has not been fully implemented yet. This paper presents the study of a complete process for Earthwork BIM design using Autodesk Civil 3D. A real site road construction project is used as a case study to explain the process of earthwork modeling, starting from laser scanning to 3D model. Quantity take off calculation is very important part of any road construction project so during this study earthwork volume from two 3D earthwork model is calculated. The results obtained through this study will be the basis for future work which has been concluded in this paper.

Estimating the lateral profile of helical piles using modified p-y springs

  • Hyeong-Joo Kim;Hyeong-Soo Kim;Peter Rey Dinoy;James Vincent Reyes;Yeong-Seong Jeong;Jun-Yong Park;Kevin Bagas Arifki Mawuntu
    • Geomechanics and Engineering
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    • 제35권1호
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    • pp.1-11
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    • 2023
  • A growing trend of utilizing helical piles for soft soil strata to support infrastructure projects is currently observed in Saemangeum, South Korea. Recognized mainly due to its ease of installation and reusability proves to be far more superior compared to other foundation types in terms of sustainability. This study applies modified p-y springs to characterize the behavior of a laterally loaded helical pile with a shaft diameter of 89.1 mm affixed with 3 helices evenly spaced along its embedded length of 2.5 m. Geotechnical soil properties are correlated from CPT data near the test bed vicinity and strain gauges mounted on the shaft surface. A modification factor is applied on the p-y springs to adjust the simulated data and match it to the bending moment, soil resistance and deflection values from the strain gauge measurements. The predicted lateral behavior of the helical pile through the numerical analysis method shows fairly good agreement to the recorded field test results.

State-of-the-art of semiactive control systems using MR fluid dampers in civil engineering applications

  • Jung, H.J.;Spencer, B.F. Jr.;Ni, Y.Q.;Lee, I.W.
    • Structural Engineering and Mechanics
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    • 제17권3_4호
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    • pp.493-526
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    • 2004
  • Semiactive control systems have received considerable attention for protecting structures against natural hazards such as strong earthquakes and high winds, because they not only offer the reliability of passive control systems but also maintain the versatility and adaptability of fully active control systems. Among the many semiactive control devices, magnetorheological (MR) fluid dampers comprise one particularly promising class. In the field of civil engineering, much research and development on MR fluid damper-based control systems has been conducted since this unique semiactive device was first introduced to civil engineering applications in mid 1990s. In 2001, MR fluid dampers were applied to the full-scale in-service civil engineering structures for the first time. This state-of-the-art paper includes a detailed literature review of dynamic models of MR fluid dampers for describing their complex dynamic behavior and control algorithms considering the characteristics of MR fluid dampers. This extensive review provides references to semiactive control systems using MR fluid dampers. The MR fluid damper-based semiactive control systems are shown to have the potential for mitigating the responses of full-scale civil engineering structures under natural hazards.

RDF와 탄화슬러지 혼합물의 열중량 및 열동역학 특성 연구 (Study on the Pyrolysis Kinetics of Mixture of RDF and Carbonized Sludge with Thermogravimetric Analysis)

  • 순지엔펑;황현욱;김명균;느지오카 안토니 무투아;이창수;김영주
    • 한국환경과학회지
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    • 제25권2호
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    • pp.281-288
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    • 2016
  • After analyzing of heating value of four kinds of RDF, the RDF-D has the highest heating value, was chosen to be mixed with carbonized sludge by different ratio. The 85%:15% ratio, which has the highest efficiency, was analyzed with thermogravimetric and pyrolysis kinetics. Applying of Kissinger method, activation energy was obtained from slope which is calculated from relation of ln(${\beta}/T^2{_m}$) and $1/T_m$. The kinetic parameters obtained from Kissinger method were 46.06 kJ/mol of RDF, 55.99 kJ/mol of carbonized sludge and 40.68 kJ/mol of mixture of RDF and carbonized sludge. The mixture of RDF and carbonized sludge has the lowest activation energy and frequency factor, during thermal decomposition reaction it has the slowest reaction rate and needs the lowest energy. Although activation energy with pyrolysis of RDF was irregularly scattered, it showed that activation energy was stabilized by co-pyrolysis of RDF and additives(Carbonized Sludge).