• Title/Summary/Keyword: shoring

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A Study on Standards for Components for Tied Post System Scaffolding and Shoring (조립형 비계 및 동바리 부재 기준에 관한 연구)

  • Moon, Seong-Oh;Lee, Sang-Yeol;Youn, Ye-Bin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.25-26
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    • 2021
  • System scaffolding and shoring are temporary structures in which vertical members, horizontal members, bracing members and trusses are assembled and installed. In order to ensure quality and safety, the quality test shall be carried out in accordance with the Guidelines for Quality Management of Construction Works (MOLIT Notice No. 2020-750). The quality test method (national standard) for Components for tied post system scaffolding and shoring is based on the Korean standards (KS F 8021) and the Safety certification standards (MOEL Notice No. 2021-22). However, the two standards differ in some aspects such as performance standards and etc, so cause confusion when applying them on-site. In addition, the standard for truss are applied only to trusses for shoring and cannot be applied to trusses for scaffolding. Therefore, this study aims to unify the two national standards and establish realistic standards.

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Determination of Efficient Shoring System in RC Frame Structures Considering Time-Dependent Behavior of Concrete (시간의존적 거동을 고려한 철근콘크리트 골조의 효율적인 지지시스템 결정)

  • 김진국;홍수미;곽효경
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.3
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    • pp.225-239
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    • 2004
  • In this paper, systematic analyses for the shoring systems installed to support applied loads during construction are performed on the basis of the numerical approach introduced in the previous study. Structural behaviors require changes in design variables such as types of shoring systems, shore stiffness and shore spacing. In this paper, the design variable are analyzed and discussed. The time dependent deformations of concrete and construction sequences of frame structures are also taken into account to minimize structural instability and to improve design of shoring system, because those effects may increase axial forces delivered to shores. From many parametric studies, it can be recommended that the most effective shoring system is 2SlR(two shores and one reshore)

Load-carrying capacities and failure modes of scaffold-shoring systems, Part I: Modeling and experiments

  • Huang, Y.L.;Chen, H.J.;Rosowsky, D.V.;Kao, Y.G.
    • Structural Engineering and Mechanics
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    • v.10 no.1
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    • pp.53-66
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    • 2000
  • This paper proposes a simple numerical model for use in a finite analysis (FEA) of scaffold-shoring systems. The structural model consists of a single set of multiple-story scaffolds with constraints in the out-of-plane direction at every connection joint between stories. Although this model has only two dimensions (termed the 2-D model), it is derived from the analysis of a complete scaffold-shoring system and represents the structural behavior of a complete three-dimensional system. Experimental testing of scaffolds up to three stories in height conducted in the laboratory, along with an outdoor test of a five-story scaffold system, were used to validate the 2-D model. Both failure modes and critical loads were compared. In the comparison of failure modes, the computational results agree very well with the test results. However, in the comparison of critical loads, computational results were consistently somewhat greater than test results. The decreasing trends of critical loads with number of stories in both the test and simulation results were similar. After investigations to explain the differences between the computationally and experimentally determined critical loads, it was recommended that the 2-D model be used as the numerical model in subsequent analysis. In addition, the computational critical loads were calibrated and revised in accordance with the experimental critical loads, and the revised critical loads were then used as load-carrying capacities for scaffold-shoring systems for any number of stories. Finally, a simple procedure is suggested for determining load-carrying capacities of scaffold-shoring systems of heights other than those considered in this study.

Load-carrying capacities and failure modes of scaffold-shoring systems, Part II: An analytical model and its closed-form solution

  • Huang, Y.L.;Kao, Y.G.;Rosowsky, D.V.
    • Structural Engineering and Mechanics
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    • v.10 no.1
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    • pp.67-79
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    • 2000
  • Critical loads and load-carrying capacities for steel scaffolds used as shoring systems were compared using computational and experimental methods in Part I of this paper. In that paper, a simple 2-D model was established for use in evaluating the structural behavior of scaffold-shoring systems. This 2-D model was derived using an incremental finite element analysis (FEA) of a typical complete scaffold-shoring system. Although the simplified model is only two-dimensional, it predicts the critical loads and failure modes of the complete system. The objective of this paper is to present a closed-form solution to the 2-D model. To simplify the analysis, a simpler model was first established to replace the 2-D model. Then, a closed-form solution for the critical loads and failure modes based on this simplified model were derived using a bifurcation (eigenvalue) approach to the elastic-buckling problem. In this closed-form equation, the critical loads are shown to be function of the number of stories, material properties, and section properties of the scaffolds. The critical loads and failure modes obtained from the analytical (closed-form) solution were compared with the results from the 2-D model. The comparisons show that the critical loads from the analytical solution (simplified model) closely match the results from the more complex model, and that the predicted failure modes are nearly identical.

Reliability Analysis of Three-Dimensional Temporary Shoring Structures Considering Bracing Member and Member Connection Condition (가새재 및 부재 연결 조건을 고려한 3차원 가설 동바리 구조물의 신뢰성 해석)

  • Ryu, Seon-Ho;Ok, Seung-Yong;Kim, Seung-Min
    • Journal of the Korean Society of Safety
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    • v.34 no.1
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    • pp.53-61
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    • 2019
  • This study performs reliability analysis of three-dimensional temporary shoring structures with three different models. The first model represents a field model which does not have diagonal bracing members. The installation of bracing members is often neglected in the field for convenience. The second model corresponds to a design model which has the bracing members with the hinge connection of horizontal and bracing members at joints. The third model is similar to the second model but the hinge connection is replaced with partial rotational stiffness. The reliability analysis results revealed that the vertical members of the three models are safe enough in terms of axial force, but the vertical and horizontal members exhibit a big difference among the three models in terms of combination stress of axial force and bi-axial bending moments. The field model showed significant increase in failure probability for the horizontal member, and thus the results demonstrate that the bracing member should be installed necessarily for the safety of the temporary shoring structures.

Calculations of Construction Loads for Flat Plates with Considering Effects of Shoring Stiffness and Slab Cracking (동바리 강성 및 슬래브 균열 영향을 고려한 플랫 플레이트의 시공하중 산정)

  • Hwang, Hyeon-Jong;Kim, Jae-Yo;Park, Hong-Gun;Hong, Geon-Ho;Lim, Joo-Hyuk;Kim, Yong-Nam
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.161-162
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    • 2009
  • In this study, the methodology of calculating the construction loads with considering effects of the shoring stiffness and slab cracks is proposed. Comparisons with the proposed method and the existing methods for construction load calculations were performed for measured shoring loads.

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Importance Analysis of Major Factors in Formwork Collapse Accident (거푸집 붕괴사고 주요 요인별 중요도 분석)

  • Park, Ji-Yeong;Kim, Gwang-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.3
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    • pp.249-256
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    • 2021
  • Fatal accidents in the construction industry account for a higher proportion than other industries, and in particular, the collapse accident of formwork is likely to lead to a serious accident like death. This study aim to derive the importance ranking of formwork collapse factors using AHP technique for preventing fatal accident. The AHP survey was conducted on field construction engineers, construction project managers, safety managers, and formwork specialist foreman with 10 years on site experience. The results of AHP analysis is that the most importance factor of formwork collapse accident is 'non-compliance with the formwork shoring assembly drawing'. Next it is important in the order of 'poor installation of formwork shoring and accessories', 'formwork shoring is not installed vertically', 'non-compliance with the concrete curing period of the formwork shoring', 'safety supervisor not designated and negligent'. It is necessary to preferentially and intensively manage the high importance factors presented as a result of this research for reducing formwork collapse accident. In addition, it will contribute to reducing construction safety accidents if the factors of the formwork collapse accident suggested in this research are included in the formwork inspection check list and checked step by step in formwork construction.

BIM-BASED PLANNING OF TEMPORARY FACILITIES FOR CONCRETE CONSTRUCTION

  • Kyungki Kim;Jochen Teizer
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.1-6
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    • 2013
  • Concrete construction requires utilization of many temporary facilities such as formwork, shoring, and scaffolding. Appropriate use of these temporary facilities greatly impacts the quality, cost, schedule, and safety of concrete construction. The current practice in design and planning of temporary facilities is often manual, error-prone, and re-active based on construction site layout, status, and progress in the field. Early design and planning of temporary facilities for concrete construction using Building Information Modeling (BIM) technology offers a potential solution. Although some commercially-available software exists that assists in the generation of temporary facility designs, the construction industry lacks tools that support detailed planning and design of many other temporary facilities. This research presents our early work in automating the design and planning of temporary facilities utilizing BIM. Algorithms were developed to automatically assess geometric conditions of work space to detect required temporary facilities and design them. The proposed methodology was implemented in a test model. By automatically incorporating temporary facilities into BIM, more realistic construction models can be created with less effort and errors. Temporary facilities-loaded models can finally be used for communication, bill of materials, scheduling, etc. and as a benchmark for field installation of temporary formwork, shoring, and scaffolding systems.

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Case Study for the Stability of Temporary Shoring Facilities at Inchon International Airport (가시설 안정성 검토에 관한 인천국제공항 시공 사례 연구)

  • 최인걸;조현모;류승철
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.97-104
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    • 1999
  • This case study has been prepared to provide the practical data about construction of temporary shoring facilities (i.e. braced sheet pile excavation) and to utilize the case study information effectively for design and construction of future facilities. This case study includes information such as 1) installing measurement devices to monitor the deformation of the sheet pile walls and the subsoil in the vicinity after establishing the criteria for the sheet pile deflection; 2) monitoring the actual movement of the temporary facility after setting up the survey control standard (due to the movement of the temporary facility) : 3) inspecting the suitability of the temporary facility construction: and 4) analyzing and studying the result of the tension test after installing ground anchors.

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Shoring STEP Data over Internet using WWW (WWW를 이용한 제품정보의 공유)

  • Choi, Young;Shin, Ha-Yong;Park, Myung-Jin;Lee, Jong-Gap
    • Journal of Korean Institute of Industrial Engineers
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    • v.23 no.3
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    • pp.597-608
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    • 1997
  • Life cycle product data is very important yet difficult to handle for manufacturing companies. Shoring and exchanging product data over world-wide-web is a part of key technology to implement PDM or CALS. STEP is widely accepted as a standard to represent the life-cycle product model data. Described in this paper is a web browser plug-in that can graphically display and explore product data represented by STEP over internet. By the use of the plug-in (named "npSTEP"), a product model data stored in STEP format on a web server can be displayed on a commonly used web client (browser), such as Netscape navigator, without any format conversion process. Furthermore one can explore the components or attributes of the product model data in hierarchical manner.

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