• Title/Summary/Keyword: Large-span structure

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Long Term Behavior of Permanent Rock Anchorages in Large Spatial Span Structures (대공간구조물에 시공된 영구앵커의 장기거동)

  • Yoo, Nam-Jae;Kim, Dae-Hak;Park, Byung-Soo;Kim, Jae-Il;Lee, Jong-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.6
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    • pp.123-135
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    • 2006
  • Most of all, large spatial span structures are the symbol of cities but have to get to supply the purpose of structure simultaneously, therefore their foundations are designed to get rolls of structure support, structure shape maintenance or overturn prevention, buoyancy resistance, etc. Accordingly various type foundations have been introduced, and after anchorage power is introduced for double structures shape maintenance and overturn prevention, change of anchorage power checked in the construction process is reviewed, comparing of playground case. Case1 anchors for the control of horizontal power worked outside hemisphere type roof, Case2 anchors for the overturn prevention of cantilever roof examined in this example. The examination has been executed by the analysis of anchorage power introduction process, related test results and anchorage power monitoring results for 2 examples.

A Study on the Stability of the Single-Layer Latticed Dome during Erection Using the Step-Up Method (Step-Up 공법에 의한 단층래티스돔의 시공시 안정성 연구)

  • Koo, Choong-Mo;Jung, Hwan-Mok;Kim, Cheol-Hwan
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.4
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    • pp.109-118
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    • 2012
  • The large-space single-layer lattice dome is relatively simpler in terms of the arrangement of the various framework members and of the design of the junction than the multi-layered lattice dome, can reduce the numbers and quantity of the framework members, and has the merit of exposing the beauty of the framework as it stands. The single-layer lattice dome, however, requires a stability investigation of the whole structure itself, along with an analysis of the stress of the framework members, because an unstable phenomenon called "buckling" occurs when its weight reaches critical levels. Many researchers have systematically conducted researches on the stability evaluation of the single-layer lattice dome. No construction case of a single-layer lattice dome with a 300-m-long span, however, has yet been reported anywhere in the world. The large-space dome structure is difficult to erect due to the gigantic span and higher ceiling compared with other common buildings, and its construction cost is generally huge. The method of erecting a structure causes major differences in the construction cost and period. Therefore, many researchers have been conducting various researches on the method of erecting such structure. The step-up method developed by these authors can reduce the construction cost and period to a great extent compared with the other general methods, but the application of this method inevitably requires the development of system supports in the center section as well as pre-existing supports in the boundary sections. In this research, the safety during the construction of a single-layer lattice dome with 300-m-long span using pre-existing materials was examined in the aspect of structural strength, and the basic data required for manufacturing the supports in the application of the step-up method developed by these authors during the erection of the roof structure were obtained.

Modal Analysis of a Large Truss for Structural Integrity (건전성 평가를 위한 대형 트러스 구조물의 모드분석)

  • Park, Soo-Yong
    • Journal of Navigation and Port Research
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    • v.32 no.3
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    • pp.215-221
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    • 2008
  • Dynamic characteristics of a structure, i.e., natural frequency and mode shape, have been widely using as an input data in the area of structural integrity or health monitoring which combined with the damage evaluation and structural system identification techniques. It is very difficult, however, to get those information by the conventional modal analysis method from large structures, such as the offshore structure or the long-span bridge, since the source of vibration is not available. In this paper, a method to obtain the frequencies and the mode shapes of a large span truss structure using only acceleration responses is studied. The calculation procedures to obtain acceleration responses and frequency response functions are provided utilizing a numerical model of the truss, and the process to extract natural frequencies and mode shapes from the modal analysis is cleary explained. The extracted mode shapes by proposed method are compared with those from eigenvalue analysis for the estimation of accuracy. The validity of the mode shapes is also demonstrated using an existing damage detection technique for the truss structure by simulated damage cases.

A Fundamental Study of Performance Based Seismic Design on the Large Span Structures: The Characteristics of Elasto-Plastic Earthquake Responses of a Steel Frame with Membrane Roof (공간구조물의 성능기초 내진설계에 관한 기초연구: 강구조 골조막 구조의 탄소성 지진응답특성)

  • Nakazawa, Shoji;Cheong, Myung-Chae;Kato, Shi;Yoshino, Tatsuya;Oda, Kenshi
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.2 s.24
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    • pp.35-44
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    • 2007
  • The characteristics of elasto-plastic responses of a gymnasium building which is a steel braced frame with membrane roof is discussed as a basic research on the performance based seismic design of large span structures, in this paper. Under the strong earthquake motions, the formation of plastic hinges on braces attached by the bottom frame make reduce down the stresses and displacements of upper structures, and vertical acceleration of the membrane is tend to increase but maximum response of strain and corresponding stresses are tend to be reduced.

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Aerodynamic mitigation of wind loads on a large-span cantilevered roof: A combined wind tunnel and CFD analysis

  • Chen Fubin;Wang Weijia;Yang Danqing;Zhenru Shu
    • Wind and Structures
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    • v.38 no.3
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    • pp.203-214
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    • 2024
  • Large-span cantilevered roof represents a unique type of structure that is vulnerable to wind loads. Inspired by the need to maximumly reducing the rooftop wind loads, this study examined the feasibility of positioning vented slots on the leading edge, and the effectiveness of such aerodynamic mitigation measures are assessed via both physical and numerical simulations. The reliability of numerical simulation was evaluated via comparisons with the wind tunnel tests. The results indicated that, the variation of venting hole arrangement can cause significant change in the rooftop wind load characteristics. For the cases involved in this study, the maximum reduction of mean and peak wind suction coefficients are found to be 9% and 8% as compared to the original circular slot without venting holes. In addition, the effect of slot shape is also evident. It was shown that the triangular shaped slot tends to increase the wind suction near the leading edge, whereas the hexagonal and octagonal shaped slots are found to decrease the wind suction. In particular, with the installation of octagonal shaped slot, the maximum reduction of wind suction coefficients near the leading edge reaches up to 31% as compared to the circular shaped slot, while the maximum reduction of mean wind suction coefficients is about 30%.

Force monitoring of Galfan cables in a long-span cable-truss string-support system based on the magnetic flux method

  • Yuxin Zhang;Xiang Tian;Juwei Xia;Hexin Zhang
    • Structural Monitoring and Maintenance
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    • v.10 no.3
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    • pp.261-281
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    • 2023
  • Magnetic flux sensors are commonly used in monitoring the cable force, but the application of the sensors in large diameter non-closed Galfan cables, as those adopted in Yueqing Gymnasium which is located in Yueqing City, Zhejiang Province, China and is the largest span hybrid space structure in the world, is seldom done in engineering. Based on the construction of Yueqing Gymnasium, this paper studies the cable tension monitoring using the magnetic flux method across two stages, namely, the pre-calibration stage before the cable leaves the rigging factory and the field tension formation stage of the cable system. In the pre-calibration stage in the cable factory, a series of 1:1 full-scale comparative tests were carried out to study the feasibility and relability of this kind of monitoring method, and the influence on the monitoring results of charging and discharging voltage, sensor location, cable diameter and fitting method were also studied. Some meaningful conclusions were obtained. On this basis, the real-time cable tension monitoring system of the structure based on the magnetic flux method is established. During the construction process, the monitoring results of the cables are in good agreement with the data of the on-site pressure gauge.The work of this paper will provide a useful reference for cable force monitoring in the construction process of long-span spatial structures.

Large eddy simulation of wind loads on a long-span spatial lattice roof

  • Li, Chao;Li, Q.S.;Huang, S.H.;Fu, J.Y.;Xiao, Y.Q.
    • Wind and Structures
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    • v.13 no.1
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    • pp.57-82
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    • 2010
  • The 486m-long roof of Shenzhen Citizens Centre is one of the world's longest spatial lattice roof structures. A comprehensive numerical study of wind effects on the long-span structure is presented in this paper. The discretizing and synthesizing of random flow generation technique (DSRFG) recently proposed by two of the authors (Huang and Li 2008) was adopted to produce a spatially correlated turbulent inflow field for the simulation study. The distributions and characteristics of wind loads on the roof were numerically evaluated by Computational Fluid Dynamics (CFD) methods, in which Large Eddy Simulation (LES) and Reynolds Averaged Navier-Stokes Equations (RANS) Model were employed. The main objective of this study is to explore a useful approach for estimations of wind effects on complex curved roof by CFD techniques. In parallel with the numerical investigation, simultaneous pressure measurements on the entire roof were made in a boundary layer wind tunnel to determine mean, fluctuating and peak pressure coefficient distributions, and spectra, spatial correlation coefficients and probability characteristics of pressure fluctuations. Numerical results were then compared with these experimentally determined data for validating the numerical methods. The comparative study demonstrated that the LES integrated with the DSRFG technique could provide satisfactory prediction of wind effects on the long-span roof with complex shape, especially on separation zones along leading eaves where the worst negative wind-induced pressures commonly occur. The recommended LES and inflow turbulence generation technique as well as associated numerical treatments are useful for structural engineers to assess wind effects on a long-span roof at its design stage.

Tensile Strength on Connection Socket of Cables (케이블 연결 소켓의 인장강도)

  • Park, Kang-Geun;Lee, Jang-Bok;Ha, Chae-Won;Kim, Jae-Bong
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.37-42
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    • 2008
  • Cable member in structure is tension systems in which the load carrying members transmit loads to support system by tensile stress with no compression or flexure allowed. Cable system have been widely used large span structure roof, air-supported structure, prestressed membrane, cable network roof, suspension structures, guyed tower, ocean platforms, suspension bridges. Cable member can transmit loads by the edge connected system such as socket, swaging, mechanical splice sleave, clip, wedge, loop splice etc. This study will shown an experimental results on the strength of connection socket of cables. In the results of experiment, most of cable connection specimen occurred the failure at the connection socket part before the cable arrived at tensile failure load.

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