• Wind and Structures
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• 제10권6호
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• pp.533-542
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• 2007

The cable-stayed-suspension hybrid bridge is a cooperative system of the cable-stayed bridge and suspension bridge, and takes some advantages and also makes up some deficiencies of both the two bridge systems, and therefore becomes strong in spanning. By taking the cable-stayed-suspension hybrid bridge, suspension bridge and cable-stayed bridge with main span of 1400 m as examples, the mechanics performance including the static and dynamic characteristics, the aerostatic and aerodynamic stability etc is investigated by 3D nonlinear analysis. The results show that as compared to the suspension bridge and cable-stayed bridge, the cable-stayed-suspension hybrid bridge has greater structural stiffness, less internal forces and better wind stability, and is favorable to be used in super long-span bridges.

• Steel and Composite Structures
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• 제44권6호
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• pp.753-768
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• 2022

In this study, a graphical automatic system is developed in order to investigate the stress redistribution of structural members in a steel cable-stayed bridge. The generalized Maxwell model is selected for stress relaxation estimation, and it is carefully verified and applied to all the cable members of a steel cable-stayed bridge to investigate its stress relaxation. A set of stress relaxation parameters in all cables is determined using the fmincon optimization function. The stress redistribution of the steel cable-stayed bridge is then analyzed using ABAQUS. To shorten the investigation time, all the aforementioned phases are built up to be an automatic system. The automatic system is then employed to investigate the effect of cable cross-section areas and girder spans on stress redistribution. The findings from these studies show that the initial tension in the cables of a steel cable-stayed bridge should be kept to less than 55% of the cable's ultimate strength to reduce the effect of cable stress relaxation. The cable space in a steel cable-stayed bridge should be limited to 15,000 mm to minimize the effect of cable stress relaxation. In comparison to other structural members of a steel cable-stayed bridge, the girders experience a significant stress redistribution.

• 한국안전학회지
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• 제18권1호
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• pp.94-100
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• 2003

Generally, cable-stayed bridges are both statically indeterminate structure with a high degree of redundancy and flexible structure. So it is very important to ensure precision control during both fabrication and construction. In precision control of cable-stayed bridges, precision control under multi-objective programming method is needed, because precision control problem of cable-stayed bridges is a multi-objective programming problem in which many objective functions are regard as variables. In previous studies, it was regarded as a single-objective problem, so it had many problems in respect of usefulness and rationalness. In this study, precision control under multi-objective programming method is proposed considering economy, efficiency, and safety at best in precision control of cable-stayed bridges. Precision control problem of cable-stayed bridges is formulated with satisfying trade-off method which is a kind of multi-objective programming method, then it is optimized with min-max method. A computer program is presented including above process.

• Structural Engineering and Mechanics
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• 제8권1호
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• pp.27-38
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• 1999

Cables are used in many applications such as cable-stayed bridges, suspension bridges, transmission lines, telephone lines, etc. Generally, the linear relationship is inadequate to present the behavior of cable structure. In finite element analysis, cables have always been modeled as truss elements. For these types of model, the nonlinear behavior of cables has been always ignored. In order to investigate the importance of the nonlinear effect on the structural system, the effect of cable stiffness has been studied. The nonlinear behavior of cable is due to its sag. Therefore, the cable pretension provides a large portion of the inherent stiffness. Since a cable-stayed bridge has numerous degrees of freedom, analytical methods at present are not convenient to solve this type of structures but numerical methods may be feasible. It is necessary to provide a different and more representative analytical model in order to present the effect of cable stiffness on cable-stayed bridges in numerical analysis. The characteristics of cable deformation have also been well addressed. A formulation of modified modulus of elasticity has been proposed using a numerical parametric study. In order to investigate realistic bridges, a cable-stayed bridge having the geometry similar to that of Quincy Bayview Bridge is considered. The numerical results indicate that the characteristics of the cable stiffness are strongly nonlinear. It also significantly affects the structural behaviors of cable-stayed bridge systems.

• 한국철도학회논문집
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• 제2권3호
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• pp.36-45
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• 1999

The basic idea of cable-stayed girder bridges is the utilization of high strength cables to provide intermediate supports for the bridge girder so that the girder can span a much longer distance. In the cable-stayed bridge, the cables exhibit nonlinear behavior because of the change in sag, due to the dead weight of the cable, which occurs with changing tension in the cable resulting from the movement of the end points of the cable as the bridge is loaded. Techniques required for the static analysis of cable-stayed bridges has been developed by many researchers. However, little work has been done on the dynamic analysis of such structures. To investigate the characteristics of the dynamic response of long-span cable-stayed bridges due to various dynamic loadings likes moving traffic loads. two different 3-D cable-stayed bridge models are considered in this study. Two models are exactly the same in structural configurations but different in finite element discretization. Modal analysis is conducted using the deformed dead-load tangent stiffness matrix. A new concept was presented by using divided a cable into several elements in order to study the effect of the cable vibration (both in-plane and swinging) on the overall bridge dynamics. The result of this study demonstrates the importance of cable vibration on the overall bridge dynamics.

• Structural Engineering and Mechanics
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• 제20권6호
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• pp.609-630
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• 2005

A reliability analysis method is proposed in this paper through a combination of the advantages of the response surface method (RSM), finite element method (FEM), first order reliability method (FORM) and the importance sampling updating method. The accuracy and efficiency of the method is demonstrated through several numerical examples. Then the method is used to estimate the serviceability reliability of cable-stayed bridges. Effects of geometric nonlinearity, randomness in loading, material, and geometry are considered. The example cable-stayed bridge is the Second Nanjing Bridge with a main span length of 628 m built in China. The results show that the cable sag that is part of the geometric nonlinearities of cable-stayed bridges has a major effect on the reliability of cable-stayed bridge. Finally, the most influential random variables on the reliability of cable-stayed bridges are identified by using a sensitivity analysis.

• Structural Engineering and Mechanics
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• 제71권3호
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• pp.271-282
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• 2019

The span record of cable-stayed bridges has exceeded 1,000 m, which makes research on the maximum possible span length of cable-stayed bridges an important topic in the engineering community. In this paper, span limit is discussed from two perspectives: the theoretical span limit determined by the strength-to-density ratio of the cable and girder, and the engineering span limit, which depends not only on the strength-to-density ratio of materials but also on the actual loading conditions. Closed form equations of both theoretical and engineering span limits of cable-stayed bridges determined by the cable and girder are derived and a detailed parametric analysis is conducted to assess the engineering span limit under current technical conditions. The results show that the engineering span limit of cable-stayed bridges is about 2,200 m based on materials used available today. The girder is the critical member restricting further increase in the span length; its compressive stress is the limiting factor. Approaches to increasing the engineering span limit are also presented based on the analysis results.

• Structural Engineering and Mechanics
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• 제29권5호
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• pp.567-579
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• 2008

To gain understanding of the applicability of CFRP cables in super long-span cable-stayed bridges, by taking a 1400 m cable-stayed bridge as example, mechanics performance including the static behavior under service load, dynamic behavior, wind stability and seismic behavior of the bridge using either steel or CFRP cables are investigated numerically and compared. The results show that viewed from the aspect of mechanics performance, the use of CFRP cables in super long-span cable-stayed bridges is feasible, and the cross-sectional areas of CFRP cables should be determined by the principle of equivalent axial stiffness.

• 한국농공학회지
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• 제36권1호
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• pp.103-115
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• 1994

The dynamic earthquake analysis of plane cable-stayed bridge structures was formulated and implemented into a computer program which analyzes plane cable-stayed bridge structu- res subjected to initial cable tensions, member dead and live loads and seismic loads. Cable-stayed bridges were modelled as multi-degrees of freedom systems with lumped- mass. Various earthquake responses such as dynamic deflection, bending moment, shear force and cable tension were investigated by the dynamic analyses in the form of the time history analysis. The time history analysis was based on the mode superposition method. The study revealed that Fan-l type cable-syayed bridges is generally superior to other types for the earthquake proof even though aspects of deflection and section force of each type presents respective advantages and disadvantages. The study provided a method to design the sections of cable-stayed bridges under seismic loads with various design parameters related to structural types. The study is expected to be useful for effective design of cable-stayed bridges with conside- ration of earthquake.

• Steel and Composite Structures
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• 제13권2호
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• pp.109-122
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• 2012

An efficient and accurate algorithm is proposed to evaluate the reliability of cable-stayed bridges accounting for soil-pile interaction. The proposed algorithm integrates the finite-element method and the response surface method. The finite-element method is used to model the cable-stayed bridge including soil-pile interaction. The reliability index is evaluated based on the response surface method. Uncertainties in the superstructure, the substructure and load parameters are incorporated in the proposed algorithm. A long span steel cable-stayed bridge with a main span length of 1088 m built in China is considered as an illustrative example. The reliability of the bridge is evaluated for the strength and serviceability performance functions. Results of the study show that when strength limit states for both girder and tower are considered, soil-pile interaction has significant effects on the reliability of steel cable-stayed bridges. Further, a detailed sensitivity study shows that the modulus of subgrade reaction is the most important soil-pile interaction-related parameter influencing the reliability of steel cable-stayed bridges.