• 제목/요약/키워드: civil works

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Estimation method of Overhead Costs for Historical Costs Estimation System of the Electrical Construction Works in Korea (국내 전기공사 분야 실적공사비 적산제도 도입시 간접공사경비의 산정방안)

  • Sohn, H.K.;Lee, H.K.;Park, M.Y.;Park, I.P.;Kwon, Y.M.;Seo, S.S.;Kim, K.G.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • 2004.05b
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    • pp.148-151
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    • 2004
  • When we have been estimated construction costs, till now, we are used to costs accumulating method of each items based on standard labors rates. But there are some problems of its methods. Our governments are applied to a historical construction costs estimation system fur building construction and civil engineering works from January 2004. The electrical construction works are forecasted that applied to historical construction cost estimation systems. This paper is supposed to reasonable estimation methods of overhead costs and profits.

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Air Diving Operation, Management and Planning for Safe and Effective Underwater Works (안전하고 효율적인 수중작업을 위한 공기잠수의 계획·운용·관리)

  • Lee, Woo Dong;Kim, Sung Gil;Kim, Myeong Hoon;Lee, Jae Hyung
    • Journal of the Korean Society of Safety
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    • v.34 no.4
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    • pp.103-110
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    • 2019
  • Underwater works are indispensable in the coastal and ocean engineering fields, and the reliance on manpower is higher than land works. Divers who work for a long time in a high-pressure underwater environment are always exposed to the risks of diving-related diseases. To prevent them, proper planning, operation, and management of diving by a supervisor with professional diving knowledge are required. This study provides the basic data for supervisors to plan, operate, and manage air diving for safe and efficient work in underwater construction sites. It is well-known that air diving simulations using the varying permeability model (VPM) require a longer decompression time as the water depth and the residence time in water increase. Therefore, it is crucial to have a proper surface interval through repetitive diving rather than single diving to improve the safety of the divers and the efficiency of underwater work. Furthermore, coastal and ocean engineers who manage and supervise underwater construction work must acquire expert knowledge on diving before they can plan, operate, and manage diving.

Effect of fine fillers from industrial waste and various chemical additives on the placeability of self-compacting concrete

  • Utepov, Yelbek;Akhmetov, Daniyar;Akhmatshaeva, Ilnur
    • Computers and Concrete
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    • v.25 no.1
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    • pp.59-65
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    • 2020
  • The premise for the study reflected in this article is the need to dispose of industrial waste, which is increasingly being used in the construction materials industry. Also, dynamically developing building industry demands attention of scientists and a direction of their works on improvement of the technology of carrying out construction works. Thus, the article is devoted to studying the influence of various chemical additives and fine fillers (industrial wastes) available in Kazakhstan on self-compacting concrete (SCC) mixtures and its rheological, physical, and technical properties. According to the studies, revealed the most efficient type of fine-dispersed filler and the most optimal type of chemical additive to enable obtaining a high-quality SCC mixture based on local raw materials. As a result, the use of microsilica in comparison with other industrial wastes resulted in a conglomerate with high compressive strength of SCC at early terms of curing. In terms of economic efficiency and quality improvement, the results of study are of practical value for the manufacturers of ready-mixed concrete operating in Kazakhstan.

Contamination of Stream and Reservoir Waters with Arsenic from Abandoned Gold Mine

  • Lee, Jin-Yong;Kim, Hee-Joung;Yang, Jai-E.
    • Environmental Engineering Research
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    • v.13 no.1
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    • pp.33-40
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    • 2008
  • Levels of arsenic in stream and reservoir waters affected by an abandoned gold mine were examined. The abandoned mine has been left without proper civil and remedial works preventing potential environmental hazards. Field and laboratory chemical analyses revealed that the stream waters downgradient from the mine area were severely contaminated with arsenic and furthermore the reservoir water, 2-3 km away from the mine, also contained substantial levels of As, far exceeding the Korean stream water standard. Relatively higher pH values (6.5-9.4) enhanced mobility of As and mainly sustained substantial As concentration in waters. Chemistries of the stream water, groundwater and reservoir water were dominated by two main factors including effects of mine effluent and anthropogenic agricultural activities. Considering that there has been a substantial As input to the reservoir and the reservoir water has been used for agricultural and domestic uses, immediate remedial works are essentially required.

An Experimental Study on the Behaviors of RC Beams Strengthened in Shear by Thin Steel Plate and Carbon Fiber Sheet (강박판 및 탄소섬유판으로 전단보강된 철근 콘크리트 보의 거동에 관한 실험적 연구)

  • 최종수;이대형;손창호;정영수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.219-223
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    • 1995
  • Since the mid of 1970's, the construction of infrastructure has been booming and accelerating to keep up with rapid economic growth. Fast achievement of most construction activities has caused unfavorable effects of civil petitions associated with damages and nuisances due to last hasty works. it is well known that the falling down of Sungsoo bridge and the collapse of Sampoong department and other structures have occurred because of the construction not conforming with the specification, and thereby incurred enormous loss of life and property. Now a days. a periodic inspection and maintenance have been strongly interested on aged RC structures, of repair and reinforcement technique in the country, most repairing and reinforcing works have been performed on the basis of the guidance of few experienced local company in this field.

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Dynamic Analysis of the Valves installed in the swash plate type of Hydraulic Driving Motor (사판식 구동 모터에 장착된 밸브의 동적거동 해석)

  • Noh, D.K.;Jang, J.S.
    • Journal of Drive and Control
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    • v.9 no.4
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    • pp.62-69
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    • 2012
  • Recently, hydraulic motor is getting the spotlight. It is resulted from rapid civil engineering public works by a lot of developing countries around the world. In this study, we divided the valves which are affixed in the hydraulic motor into some parts, implemented them through computer simulation, verified validation of each component, and analyzed behavior adding driving condition. Through the analyzed results with general driving condition, we found the reason why behavior became unstable as the motor had started spinning. Through the analyzed results with tough driving condition, we verified that the valve works well with it's production purpose.

Geological feasibility and slope stability analysis under GIS environment for rail route alignment

  • Jain, Kamal;Kumar, Anand
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.186-188
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    • 2003
  • Rail Route Alignment in hilly terrain is a difficult task to implement as several natural constraints poses threat to the safety and stability of the alignment. The conventional methods followed to find out the final location survey or the feasibility analysis for alignment is time taking consuming. Some times, due to inaccessibility of the terrain it becomes impossible to carry out such works. The construction works in hilly terrain, which are associated with the proposed alignment, are not same as carried out in plane areas due to a vast contrast between the two areas. Different geological structures such as faults, thrusts, synclines and anticlines are a big problem to carry out normal construction practices. Thus for a safe and stable railway route in the unstable hilly areas, it is required to carry out the feasibility analysis of the proposed alignment to assist the policy makers for a successful implementation of the alignment. In the present work Remote Sensing and GIS has been successfully used to carry out geological feasibility and slope stability analysis for rail route alignment work.

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A Study on the Civil Costumes Appeared on Dutch Paintings in the 17th Century (17세기(世紀) 네덜란드 회화(繪畵)에 나타난 시민복식(市民服飾)에 관(關)한 연구(硏究))

  • Yoo, Joo-Lee;Cho, Oh-Soon
    • Journal of Fashion Business
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    • v.3 no.2
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    • pp.37-47
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    • 1999
  • In the 17th century, Europe had changed from medieval feudalistic ages into an absolute monarchy taking Catholicism and absolute monarchism together. On the other hand, Holland achieved prosperity in economy, culture, and arts through gradual enlightment of the people by winning independence from Spain, and religious reformation. The culture dress and its ornaments at the time was led by the governing class such as royal families and its aristocracy in Europe, while Holland, united republic country at the time, brought civil costume nationwide wholly by civil class and its effect to other neighboring countries in Europe. In addition, the origin of modern dress and its ornaments dates back to that time. Moreover, civil-looking dutch paintings found its sources in routine daily life and became realistic. With this respect, in this research, we put our purpose of the research in making a better and more understanding of the modern costume and its ornaments and exploring the spirit of human beings by analyzing dutch civil costumes shown in these artistic works. It is very important that this research is rather renovational comparing with prior ones focused on those of ruling classes. As a result of the research, the distinguished parts of the civil costumes appeares as following beauties. First, functional beauty was respected such as natural waist line, peplum, gather of the skirt and sleeve, apron, head towel were some of the examples to those in their costumes and its ornaments. Second, with respect to humanity under rough natural surroundings and long struggle with outside tribes, humanity of costume was brought by optimistic and even free mind to them. The three quater sleeve showed wrist and deep-cut decollete in their dress and ornaments. Third, with respect to simplicity, religious effect on the leading civil class demanding self-abstinence, frugality, and thrift in their way of life resulted in black-tone simple costumes with white collar in their costumes and its ornaments.

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Computer vision and deep learning-based post-earthquake intelligent assessment of engineering structures: Technological status and challenges

  • T. Jin;X.W. Ye;W.M. Que;S.Y. Ma
    • Smart Structures and Systems
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    • v.31 no.4
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    • pp.311-323
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    • 2023
  • Ever since ancient times, earthquakes have been a major threat to the civil infrastructures and the safety of human beings. The majority of casualties in earthquake disasters are caused by the damaged civil infrastructures but not by the earthquake itself. Therefore, the efficient and accurate post-earthquake assessment of the conditions of structural damage has been an urgent need for human society. Traditional ways for post-earthquake structural assessment rely heavily on field investigation by experienced experts, yet, it is inevitably subjective and inefficient. Structural response data are also applied to assess the damage; however, it requires mounted sensor networks in advance and it is not intuitional. As many types of damaged states of structures are visible, computer vision-based post-earthquake structural assessment has attracted great attention among the engineers and scholars. With the development of image acquisition sensors, computing resources and deep learning algorithms, deep learning-based post-earthquake structural assessment has gradually shown potential in dealing with image acquisition and processing tasks. This paper comprehensively reviews the state-of-the-art studies of deep learning-based post-earthquake structural assessment in recent years. The conventional way of image processing and machine learning-based structural assessment are presented briefly. The workflow of the methodology for computer vision and deep learning-based post-earthquake structural assessment was introduced. Then, applications of assessment for multiple civil infrastructures are presented in detail. Finally, the challenges of current studies are summarized for reference in future works to improve the efficiency, robustness and accuracy in this field.

Theoretical buckling analysis of inhomogeneous plates under various thermal gradients and boundary conditions

  • Laid Lekouara;Belgacem Mamen;Abdelhakim Bouhadra;Abderahmane Menasria;Kouider Halim Benrahou;Abdelouahed Tounsi;Mohammed A. Al-Osta
    • Structural Engineering and Mechanics
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    • v.86 no.4
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    • pp.443-459
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    • 2023
  • This study investigates the theoretical thermal buckling analyses of thick porous rectangular functionally graded (FG) plates with different geometrical boundary conditions resting on a Winkler-Pasternak elastic foundation using a new higher-order shear deformation theory (HSDT). This new theory has only four unknowns and involves indeterminate integral variables in which no shear correction factor is required. The variation of material properties across the plate's thickness is considered continuous and varied following a simple power law as a function of volume fractions of the constituents. The effect of porosity with two different types of distribution is also included. The current formulation considers the Von Karman nonlinearity, and the stability equations are developed using the virtual works principle. The thermal gradients are involved and assumed to change across the FG plate's thickness according to nonlinear, linear, and uniform distributions. The accuracy of the newly proposed theory has been validated by comparing the present results with the results obtained from the previously published theories. The effects of porosity, boundary conditions, foundation parameters, power index, plate aspect ratio, and side-to-thickness ratio on the critical buckling temperature are studied and discussed in detail.