• Title/Summary/Keyword: large-scale construction

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Prefabricated Apartments Project Using Precast Concrete Large Panel System (프리캐스트 콘크리트 대형 패널을 이용한 조립식 아파트 공사)

  • 박의식
    • Proceedings of the Korea Concrete Institute Conference
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    • 1989.10a
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    • pp.49-52
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    • 1989
  • This report introduces the large scale prefabricated apartment project in Saudi Arabia designed and built by Hyundai Engineering and construction Co. as turn-key basis from ministry of Public works and ltousing of Saudi Arabia. This project using precast large panel system is 7,600 dwelling unit, total building area 1.8 mil sguare meters. Large panel system is a kind of industrialized building method which classified as monolithic system, total system and structural system. Hyundai Engineering and Construction Co. develop his own prefabricated large panel system for this project and named "HYUNDAI SYSTEM". The key point of this system is vertical and horizontal joints between panels. Also stability of whole building structure is especially important for this kind of prefabricated building. building.

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A proposal of switching control system based on speculative control and its application to antiskid braking system

  • Masaaki Inaba;Ikuo Yoshinhara;Hai-jiao Guo;Kazuo Nakao;Kenichi Abe
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.585-588
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    • 1997
  • This paper presents a construction method of logic-based switching control system which operates in widely changing environments. The logic-based switching controller is composed of a family of candidate controllers together with a supervisor. The system does not require any identification schemes of environments. Switching from one candidate controller to another is carried out based on monitoring the output of the system. The basic ideas of adaptation are as follows: (1)each candidate controller is prepared for each environment in advance; (2)the supervisor applies a sequence of speculative controls to a plant with candidate controllers just after the control has started and just after the change of the environment has been detected. It is important that each candidate controller can keep the system stable during a sequence of speculative controls, and the most appropriate candidate controller for the environment to which the system is exposed can be selected before the last speculative control is ended. An application to an antiskid braking system clarifies the effectiveness of the proposed method.

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On Subgrid-Scale Models for Large-Fddy Simulation of Turbulent Flows (난류유동의 큰 에디 모사를 위한 아격자 모델)

  • Gang, Sang-Mo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.11
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    • pp.1523-1534
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    • 2000
  • The performance of a number of existing dynamic subgrid-scale(SGS) models is evaluated in large-eddy simulations(LES) of two prototype transitional and turbulent shear flows, a planar jet and a channel flow. The dynamic SGS models applied include the dynamic Smagorinsky model(DSM);Germano et al. 1991, Lully 1992), the dynamic tow-component model(DTM; Akhavan et al. 2000), the dynamic mixed model(DMM;Zang et al, 1993). and the dynamic two-parameter model(DTPM; Salvetti & Banerjee 1995). The results are compared with those for DNS for their evaluation. The LES results demonstrate the superior performance of DTM with use of a sharp cutoff filter and DMM with use of a box filter, as compared to their respect counterpart DSM, in predicting the mean statistics, spectra and large-scale structure of the flow, Such features of DTM and DMM derive from the construction of the models in which tow separate terms are included to represent the SGS interactions; a Smagorinsky edd-viscosity term to account for the non-local interactions, and a local-interaction term to account for the nonlinear dynamics between the resolved and subgrid scales in the vicinity of the LES cutoff. As well, overall the SGS models using a sharp cutoff filter are more successful than those using a box filter in capturing the statistics and structure of the flow. Finally, DTPM is found to be compatible or inferior to DMM.

Case Study on Large Cutting Slope Failure (대규모 사면의 붕괴사례)

  • 박영목
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.27-43
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    • 2002
  • This paper described two case studies on large scale failure of cutting slope. The kind of rock in both sites predominated limestone and shale respectively. These cutting slopes located in northern area of Gyongbug Province are composed of very complicated and various rock mass. Geological characteristics, causes of failure, proceeding of security diagnose, maintenance method etc. of two sites were carried out to check the cutting slope stability and to provide reasonable maintenance method. This paper may provide the useful data for engineers related with design and construction of large cutting slope.

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Efficacy of Starch and PVA (polyvinyl alcohol) for the Suppression of Soil Dust Emissions from Large-scale Construction Sites in Urban Areas (도심 대형사업장의 토양 입자 비산 억제를 위한 Starch와 PVA(polyvinyl alcohol)의 효율성 평가)

  • Choi, Jong-Soo;Kim, Dong-Su;Choi, Yu-Lim;Kim, Jung-Eun;Yang, Jae-Kyu;Chang, Yoon-Young
    • Journal of Soil and Groundwater Environment
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    • v.24 no.6
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    • pp.9-15
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    • 2019
  • Soil dust emitted from large scale construction sites in urban areas has posed a significant health threats to local residents by exacerbating air quality. Water-spraying (moistening) is commonly practiced to lower the dust emission in construction sites, but its long term effectiveness is highly questionable. In this study, the utility of starch and PVA(polyvinyl alcohol) was investigated in suppression of the soil dust emissions in construction sites in Seoul areas. The efficiency of the two suppressants was tested with test soil sample in a lab-scale wind tunnel box under different concentrations of suppressants and soil textures. Starch and PVA showed the superior ability to suppress soil dust emission as compared to moistening, resulting in PM10 and PM2.5 lower than the daily limit values of 30 and 15 ㎍/㎥ respectively. PVA showed higher suppression capability than starch for all conditions. The test soils mixed with suppressants also showed dramatically enhanced aggregate stability compared to the non-treated soil.

Interface Management Practices for Minimizing Design Change - Focusing on the Case Study - (설계간섭 최소화를 위한 인터페이스 관리방안 - 사례현장 적용 내용을 중심으로 -)

  • Ahn, Sanghyun
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.6
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    • pp.22-29
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    • 2013
  • As construction projects are getting larger, more complex and specialized, the size and scale of the structures are increasing and large-scale projects with multiple participants involved have continuously been ordered. Due to the nature of a large-scale construction project, when there are interferences and conflicts in process, schedule and area among project participants, the project requires more time and efforts to resolve the issues as it progresses further. This study suggests the interface management model that is time-saving and physically beneficial in solving interface issues based on case study. This study provides a practical management model including the organization of interface consultative group, checklist preparation, LIST management and PMIS application, which will be useful for the construction sites seeking effective know-how to manage design interferences and changes.

Noise Management Process for Big Scale Concrete Pouring in Urban Area (도심지 대규모 콘크리트 타설시 소음관리 사례)

  • An, Jang-Ho;Lee, Joo-Ho;Lee, Jun-Seo;Kim, Il-Min
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.04a
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    • pp.787-790
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    • 2012
  • In downtown, construction noise related claims are the most important issues. Sometimes noise related claims halt the construction process. Therefore, Introduction of noise reduction measures is common to construction process with a loud noise. This case is about concrete pouring for mat foundation of super tall building. Concrete pouring process using High Pressure Pumping machine causes high noise level in the vicinity of area. And large number of transit-mixer truck cause traffic congestion. This paper introduces effort and process to prevention of construction noise claims on massive scale concrete pouring.

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Repair and Construction Methods of Hanyangdoseong in 18th Century (18세기 한양도성의 개축과 축성기법)

  • Song, In Ho;Kim, Young Soo;Moon, In Sik
    • Journal of architectural history
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    • v.30 no.4
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    • pp.79-90
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    • 2021
  • Since its construction in the late 14th century, Hanyangdoseong had been carried out three major repairs and reconstructions during the 500 years of the Joseon Dynasty. In addition to the large-scale construction, small-scale construction continued until King Gojong era. In particular, in the 18th century, systematic construction management was implemented by the craftsmen and the military participated in the renovation of Hanyangdoseong in earnest, and the construction methods also developed rapidly. In the early 18th century, new construction techniques were attempted in various sections of the reconstruction work, and gradually became a common technology for repairing Hanyangdoseong in the late 18th century. The purpose of this study is to examine the characteristics and period of changes in the 18th century's construction technique, when the rapid development of Hanyangdoseong took place. To this end, the excavation results related to Hanyangdoseong, the remaining city wall, and the inscribed stones were used to identify and demonstrate the characteristics and change of the construction method.