scholarly journals Seismic Fragility Assessment of an Isolated Multipylon Cable-Stayed Bridge Using Shaking Table Tests

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Yutao Pang
Keyword(s):  
Fragility Curves ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Shaking Table ◽  
Seismic Fragility ◽  
Shaking Table Tests ◽  
Three Dimensional Model ◽  
Cable Stayed Bridge ◽  
High Flexibility ◽  
Cable Stayed Bridges

In recent decades, cable-stayed bridges have been widely built around the world due to the appealing aesthetics and efficient and fast mode of construction. Numerous studies have concluded that the cable-stayed bridges are sensitive to earthquakes because they possess low damping characteristics and high flexibility. Moreover, cable-stayed bridges need to warrant operability especially in the moderate-to-severe earthquakes. The provisions implemented in the seismic codes allow obtaining adequate seismic performance for the cable-stayed bridge components; nevertheless, they do not provide definite yet reliable rules to protect the bridge. To date, very few experimental tests have been carried out on the seismic fragility analysis of cable-stayed bridges which is the basis of performance-based analyses. The present paper is aimed at proposing a method to derive the seismic fragility curves of multipylon cable-stayed bridge through shake table tests. Toward this aim, a 1/20 scale three-dimensional model of a 22.5 m cable-stayed bridge in China is constructed and tested dynamically by using the shaking table facility of Tongji University. The cable-stayed bridge contains three pylons and one side pier. The outcomes of the comprehensive shaking table tests carried out on cable-stayed bridge have been utilized to derive fragility curves based on a systemic approach.

scholarly journals Impact of Wall Configurations on Seismic Fragility of Steel-Sheathed Cold-Formed Steel-Framed Buildings

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Liqiang Jiang ◽  
Jihong Ye
Keyword(s):  
Fragility Curves ◽  
Shaking Table ◽  
Seismic Fragility ◽  
Shaking Table Tests ◽  
Cold Formed Steel ◽  
Analytic Models

Seismic fragility of steel-sheathed cold-formed steel-framed (CFSF) structures is scarcely investigated; thus, the information for estimation of seismic losses of the steel-sheathed CFSF buildings is insufficient. This study aims to investigate the seismic fragility of steel-sheathed CFSF buildings with different wall configurations. Analytic models for four 2-story steel-sheathed CFSF buildings are established based on shaking table tests on steel-sheathed CFS walls. Then, a group of fragility curves for these buildings are generated. The results show that the thickness of steel sheathing and the fastener spacing of the wall have significant impact on seismic fragility of steel-sheathed CFSF buildings. The seismic fragility of the CFSF building can be reduced by increasing the thickness of steel sheathing or decreasing the fastener spacing. By increasing the thickness of steel sheathing, the reduction on probability is more obvious for the CP limit. It is also found that the exceeding probability is approximately linear with fastener spacing, with a slope in the range from 0.25%/mm to 0.50%/mm.

Comparative dynamic investigation of cross-laminated wooden panel systems: Shaking-table tests and analysis

2017 ◽  
Vol 21 (10) ◽  
pp. 1421-1436 ◽  
Author(s):  
Viktor Hristovski ◽  
Violeta Mircevska ◽  
Bruno Dujic ◽  
Mihail Garevski
Keyword(s):  
Energy Dissipation ◽  
Earthquake Engineering ◽  
Dynamic Properties ◽  
Seismic Energy ◽  
Experimental Tests ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Equivalent Viscous Damping ◽  
Cross Laminated Timber ◽  
Engineering Seismology

Cross-laminated timber has recently gained great popularity in earthquake-prone areas for construction of residential, administrative, and other types of buildings. At the Laboratory of the Institute of Earthquake Engineering and Engineering Seismology in Skopje, comparative full-scale shaking-table tests of cross-laminated timber panel systems have been carried out as a part of the full research program on the seismic behavior of these types of wooden systems, realized by Institute of Earthquake Engineering and Engineering Seismology, Skopje, and the Faculty of Civil and Geodetic Engineering (UL FCG), University of Ljubljana. Two different specimens built of cross-laminated timber panels have been tested: specimen containing a pair of single-unit principal wall elements (Specimen 1) and specimen containing a pair of two-unit principal wall elements (Specimen 2). In this article, the results from the shaking-table tests obtained for Specimen 2 and numerically verified by using appropriate finite element method–based computational model are discussed. Reference is also made to the comparative analysis of the test results obtained for both specimens. One of the most important aspects of the research has been the estimation of the seismic energy-dissipation ability of Specimen 1 and 2, via calculation of the equivalent viscous damping using the performed experimental tests. It is generally concluded that Specimen 2 exhibits a similar rocking behavior as Specimen 1, with similar energy-dissipation ability. Both specimens have manifested slightly different dynamic properties, mostly because Specimen 2 has been designed with one anchor more compared to Specimen 1. Forced vibration tests have been used for identification of the effective stiffness on the contacts for Specimen 2. This research is expected to be a contribution toward clarification of the behavior and practical design of cross-laminated timber panel systems subjected to earthquake loading.

scholarly journals Investigation of the Effect of the Deck Material on the Cost in Cable-Stayed Bridges with Different Spans

2021 ◽  
Vol 10 (1) ◽  
pp. 11-33
Author(s):  
Ali Köken ◽  
Ahmed Ali Abdulqader Farhad
Keyword(s):  
Reinforced Concrete ◽  
Three Dimensional Model ◽  
Main Bearing ◽  
Analysis And Design ◽  
Bridge Program ◽  
Cable Stayed Bridge ◽  
The World ◽  
The Cost ◽  
Cable Stayed Bridges ◽  
Bridge System

Abstract Recent developments in the social sphere also cause an increase in transportation activities. Increased transport activities lead to the construction of new roads and bridges. Different bridge construction systems are available to overcome large span obstacles. Cable-stayed bridges are more advantageous construction systems than other bridge type building carrier systems in overcoming large spans through suspension cables. Therefore, it is also widely preferred by designers. The biggest factor in the development of cable-stayed bridges is undoubtedly steel cables. Cable-stayed bridges are bridge structures that become lighter with the increase of the span, which has a more expanded flexibility, and that includes a cable system with the effect of nonlinear factors. Costs of cable-stayed bridges vary according to different spans. The span as well as the deck material used in the bridge system have a great effect on the cost. In cable-stayed bridge systems, decks are constructed of reinforced concrete and steel. The costs of cable-stayed bridges are widely discussed around the world; therefore, the effect of the span and deck material on the cost of cable-stayed bridges is being investigated. The main bearing elements of such bridges are cables, decks, and towers, and among these elements, the tower bridge carries all the weight of the bridge, even other external loads such as vehicle, wind, etc. In this study, the three-dimensional model of the cable, deck and tower elements that make up the cable-stayed bridge system was created and analysed using the CSI Bridge Program. The AASHTO LRFD Standards, which are widely used in the analysis of bridge systems with the CSI Bridge program and the design of bridge systems in the world, were used. In the study, the analysis and designs of cable-stayed bridges with reinforced concrete and steel deck at 250, 500, 750, 1000, 1500, 2000 meters span were carried out. The amount of materials and costs used in the analysis and design of the cable-stayed bridge systems were obtained and the results were interpreted.

Experimental Study on Three-Dimensional Base-Isolated Model with 3DIB

2011 ◽  
Vol 255-260 ◽  
pp. 2325-2329
Author(s):  
Ya Min Zhao ◽  
Jing Yu Su ◽  
Ming Lu
Keyword(s):  
Three Dimensional ◽  
Shaking Table ◽  
Vertical Acceleration ◽  
Shaking Table Tests ◽  
3 Dimensional ◽  
Horizontal Acceleration ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Disk Spring ◽  
Fixed Base

A new 3-dimensional isolation bearing (3DIB), which is combined with lead rubber bearing (LRB) and disk spring bearing (DSB), is introduced in this paper. A series of shaking table tests of the 1/2 scale fixed-base and 3DIB base-isolated model were compared to confirm the validity of the 3DIB. Results show that the 3DIB can isolate 3-dimensional earthquake energy remarkably. Large displacement of the 3DIB base-isolated system occurred on the isolation layer, and the inter-story deformation of the superstructure changed slightly. The horizontal acceleration responses of 3DIB model decreased more than 60% and the vertical acceleration responses decreased more than 50% under the severe earthquake of 0.4g in PGA input, which confirmed that 3DIB could isolate both the horizontal and vertical earthquakes obviously.

scholarly journals Seismic Vulnerability Assessment of Hybrid Mold Transformer Based on Dynamic Analyses

2019 ◽  
Vol 9 (15) ◽  
pp. 3180
Author(s):  
Ngoc Hieu Dinh ◽  
Joo-Young Kim ◽  
Seung-Jae Lee ◽  
Kyoung-Kyu Choi
Keyword(s):  
Analytical Model ◽  
Degrees Of Freedom ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Shaking Table ◽  
Exceedance Probability ◽  
Shaking Table Tests ◽  
Performance Levels ◽  
Analytical Results ◽  
Dynamic Analyses

In the present study, the seismic vulnerability of a hybrid mold transformer was investigated using a dynamic analytical approach incorporating the experimental results of shaking table tests. The analytical model consisted of linear springs and plastic beam elements, and it has six degrees of freedom simulating the hybrid mold transformer. The dynamic characteristics of the analytical model were determined based on the shaking table tests. The reliability of the analytical model was verified by comparing the test results and analytical results. In order to assess the seismic vulnerability, three critical damage states observed during the shaking table tests were investigated by incorporating the three performance levels specified in ASCE 41-17. Comprehensive dynamic analyses were performed with a set of twenty earthquakes in consideration of the variation of the uncertain parameters (such as the effective stiffness and coil mass) of the mold transformer. Based on the analytical results, fragility curves were established to predict the specified exceedance probability of the mold transformer according to the performance levels.

Improved finite strip method for nonlinear analysis of long-span cable-stayed bridges

1990 ◽  
Vol 17 (1) ◽  
pp. 87-93 ◽  
Author(s):  
M. S. Cheung ◽  
Wenchang Li ◽  
L. G. Jaeger
Keyword(s):  
Three Dimensional ◽  
Structural Response ◽  
Finite Strip ◽  
Strip Method ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Finite Strip Method ◽  
Nonlinear Solutions ◽  
Raphson Iteration ◽  
Cable Stayed Bridges

As the spans of cable-stayed bridges increase, the degree of nonlinearity of structural response increases markedly. For future spans greater than (say) 800 m, existing three-dimensional software then becomes very time consuming and costly, and a finite strip approach becomes more attractive and preferable. An improved finite strip method using two types of longitudinal shape functions is developed in this paper for the analysis of girders of such bridges. The nonlinearities due to sag and angle change of the cables are taken into account by means of catenary theory. The substructuring technique and the modified Newton–Raphson iteration method are used for nonlinear solutions. A number of numerical examples are given to show the accuracy and efficiency of this method. Key words: finite strip, continuous structure, cable-stayed bridge, substructuring, catenary, nonlinearity, iteration.

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