• Title/Summary/Keyword: 시방서

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Simplified Load Distribution Factor Equation for the Design of Composite Steel Girder Bridges (강합성교 설계를 위한 하중분배계수 간략식)

  • Chung, Wonseok
    • Journal of Korean Society of Steel Construction
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    • v.17 no.2 s.75
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    • pp.131-138
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    • 2005
  • The AASHTO wheel load distribution factor (LDF) equation has been with us since 1931 and has undergone minor modifications. In 1994, an entirely new procedure was introduced in the AASHTO LRFD code based on parametric studies and finite element analyses. However, this LDF equation involves a longitudinal stiffness parameter, the design of which is not initially known. Thus, an iterative procedure is required to correctly determine the LDF value. The increased level of complexity puts undue burden on the designer resulting in a higher likelihood for misinterpretation and error. In this study, based on current AASHTO LRFD framework, a new simplified equation is developed that does not require an iterative procedure. A total of 43 representative composite steel girder bridges are selected and analyzed using a finite element model.The new simplified equation produces LDF values that are always conservative when compared to those obtained from the finite element analyses and are generally greater than the LDF obtained using AASHTO LRFD specification. Therefore, the proposed simplified equation is expected to streamline the determination of LDF for bridge design without sacrificing safety.

Establishment of Building Work Section of LH Guide Specifications (건축부문 LH 전문시방서 작성 방안)

  • Oh, Eun-Ho;Kim, Tae-Song;Lee, Kab-Won;Koo, Jai-Dong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.177-179
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    • 2011
  • The difference the guide specifications of between housing and land development has been caused many problems, since Korea Land Corporation and Korea Housing Corporation were merged into LH (Land and Housing Corporation) in 2009. Those are that specification criteria to establishing lower level specifications are disordered; duplicated investment on sites; management systems are conflicted site to site, which are based on different operation system from old land and housing corporations, etc. Thus, this paper aims to suggest a direction of integrated guide specification system of LH including improved and advanced classification hierarchy and specification.

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Liquefaction Susceptibility of Quay Walls to Earthquake Loadings (지진으로 인한 안벽의 액상화 위험도 평가)

  • 권오순;박우선;윤길림
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.12 no.1
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    • pp.27-38
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    • 2000
  • The collapses and settlement of harbor facilities from earthquakes were known due mostly to liquefaction of reclaimed land. The most harbor quay wa1ls being designed as gravity types in Korea are known susceptible structures to liquefaction because reclaimed land was not treated resistant to earthquake. In this study, liquefaction susceptibility of reclaimed land behind a large quay walls under construction to earthquake was predicted and its stability was analyzed. In addition, liquefaction prediction methods in harbor facilities specification adopted by both Korea and Japan were compared by applying the methods to prediction of liquefaction susceptibility of reclaimed land, respectively.

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Response Modification Coefficient Using Natural Period (고유진동주기를 이용한 응답수정계수)

  • 김희중
    • Computational Structural Engineering
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    • v.9 no.4
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    • pp.229-237
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    • 1996
  • In some current procedures, ground motions from different sources have been scaled by their peak ground accelerations and combined to obtain smoothed response spectra for specific regions. As consideration of the inelastic deformation capacity of structure, inelastic deformations are permitted under seismic ground excitation in all codes. In the ATC(Applied Technology Council) and UBC(Uniform Building Code), the inelastic design spectrum is obtained by reducing the elastic design spectrum by a factor that is independent of structural period. In this study, the average of nonlinear response spectra calculated from a sample of 20 records for each event are constructed to obtain the smoothed response spectra. These response spectra are used to examine the effects of structural strength factors such as the yield strength ratio and damping value. Through the regression analysis of nonlinear response of system for a given damping value and yield strength ratio, the required yield strength for seismic design can be estimated for a certain earthquake event. And a response modification coefficient depending on the natural period for current seismic design specifications are proposed.

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Development of an Automatic Classification Model for Construction Site Photos with Semantic Analysis based on Korean Construction Specification (표준시방서 기반의 의미론적 분석을 반영한 건설 현장 사진 자동 분류 모델 개발)

  • Park, Min-Geon;Kim, Kyung-Hwan
    • Korean Journal of Construction Engineering and Management
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    • v.25 no.3
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    • pp.58-67
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    • 2024
  • In the era of the fourth industrial revolution, data plays a vital role in enhancing the productivity of industries. To advance digitalization in the construction industry, which suffers from a lack of available data, this study proposes a model that classifies construction site photos by work types. Unlike traditional image classification models that solely rely on visual data, the model in this study includes semantic analysis of construction work types. This is achieved by extracting the significance of relationships between objects and work types from the standard construction specification. These relationships are then used to enhance the classification process by correlating them with objects detected in photos. This model improves the interpretability and reliability of classification results, offering convenience to field operators in photo categorization tasks. Additionally, the model's practical utility has been validated through integration into a classification program. As a result, this study is expected to contribute to the digitalization of the construction industry.

Assessment of Partial Safety Factors for Limit States Design of Foundations (한계상태설계법의 기초설계 적용을 위한 부분안전계수의 평가)

  • Kim Bum-Joo
    • Journal of the Korean Geotechnical Society
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    • v.20 no.9
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    • pp.77-89
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    • 2004
  • While limit states design (LSD) is currently the standard structural design practice, it is relatively new in the geotechnical design. Adoption of LSD far geotechnical design is an international trend. In the present study, various LSD codes from the United States, Canada, and Europe were reviewed. A simple first-order-second-moment (FOSM) reliability analysis was performed to determine theoretically the ranges of load and resistance factor values for representative loads and foundation bearing capacity, respectively. In order for foundation design to be consistent with current structural design practice, it would be desirable to use the same loads, load factors and load combinations. The values of load factor, obtained from the FOSM analysis, were found to be generally consistent with those given in the codes, whereas the values of resistance factor indicated overall lower ranges due to high values of coefficient of variation used in the analysis. Since the degree of uncertainties included in bearing capacity of foundations varies with the methods used to estimate the bearing capacity, different values of resistance factor should be used fur different methods. For the purpose, continuous efforts are needed to be made first to accurately identify and quantify the uncertainties in the methods.

A Study on Landscaping Repair Work Classifications in Cultural Heritage Industry (문화재 수리의 조경분야 공종 분류에 관한 연구)

  • Kim, Min-Seon;Lee, Jae-Yong;Kim, Choong-Sik
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.40 no.2
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    • pp.59-66
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    • 2022
  • The purpose of this study was to suggest the landscaping repair work classification, the standard for securing the independence of and establishing the scope of landscaping repair works. Standard construction specifications currently specify the landscaping repair work classification around the planting construction, while standard work estimate does not include the field of landscaping. The landscaping construction specifications and the standard work estimate in the construction industry should be, however, applied, so it is difficult to specifically understand what is the landscaping repair work classification in the cultural heritage industry. From 1961 to 1980, not only the tree planting but also a variety of landscaping facilities had been specified as the landscaping repair works, and it was found that all of these work classifications are established as the landscaping repair work classifications in the construction industry. A total of 20 work classifications were verified by comprehensively arranging those specified in notices of tender for working drawing services for cultural heritages during three years, from 2018 to 2020, except for those for the maintenance and Dancheong of architectures, plant protection and conservation. All 20 work classifications corresponded to the landscaping work classifications in the construction industry. On the basis of the landscaping work classifications in the construction industry, this study divided the landscaping repair work classifications into site-building and shaping, planting work, facility construction, paving work, ecological landscape architectural construction and vegetation maintenance, by considering the specialty of cultural heritage space.

Development of Drawing & Specification Management System Using 3D Object-based Product Model (3차원 객체기반 모델을 이용한 설계도면 및 시방서관리 시스템 구축)

  • Kim Hyun-nam;Wang Il-kook;Chin Sang-yoon
    • Korean Journal of Construction Engineering and Management
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    • v.1 no.3 s.3
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    • pp.124-134
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    • 2000
  • In construction projects, the design information, which should contain accurate product information in a systematic way, needs to be applicable through the life-cycle of projects. However, paper-based 2D drawings and relevant documents has difficulties in communicating and sharing the owner's and architect's intention and requirement effectively and building a corporate knowledge base through on-going projects due to Tack of interoperability between specific task or function-oriented software and handling massive information. Meanwhile, computer and information technologies are being developed so rapidly that the practitioners are even hard to adapt them into the industry efficiently. 3D modeling capabilities in CAD systems are enormously developed and enables users to associate 3D models with other relevant information. However, this still requires a great deal of efforts and costs to have all the design information represented in CAD system, and the sophisticated system is difficult to manage. This research focuses on the transition period from 2D-based design Information management to 3D-based, which means co-existence of 2D and 3D-based management. This research proposes a model of a compound system of 2D and 3D-based CAD system which presents the general design information using 3D model integrating with 2D CAD drawings for detailed design information. This research developed an integrated information management system for design and specification by associating 2D drawings and 3D models, where 2D drawings represents detailed design and parts that are hard to express in 3D objects. To do this, related management processes was analyzed to build an information model which in turn became the basis of the integrated information management system.

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