Cable-stayed System Research Articles

The mystery of the partially collapsed Izbor viaduct

On Saturday, 6 May 2006, the launching of the deck superstructure of the Izbor viaduct resulted in the partial collapse of the front section of the launched deck. The construction process of launching the deck was aided by a tower and supporting cable-stayed system. This paper describes the investigation, including on-site material inspections and in-depth analysis, which was carried out to determine the likely cause of the partial collapse. The design and construction deficiencies, which were identified during the assessment of the viaduct, allowed an understanding of the anatomy of the partial failure. Following the investigation, the mystery of the Izbor viaduct was revealed.

Analysis and design procedure of hybrid long-span cable-stayed bridge using advanced composite material

An innovative solution is proposed in this paper by introducing a hybrid-type cable stayed bridge as a competent system to safely bridge very long spans. The new system leads into huge reduction in deck weight and its critical stresses in the pylon zones by using hybrid advanced composite deck. It also reduces the stiffness losses of the stay-cables due to the catenary’s action by using carbon fiber reinforced polymer cables. The paper proposes a proper consistent and systematic analysis and design procedure that optimize and precisely simulate the proposed bridge system. It recognizes the changes in structural behavior of the cable-stayed system, accordingly it clearly defines the ultimate and serviceability limit states for such new structural system in consistence with the limit state design philosophy. The design steps of the ADP represent a multi-scale design technique while the analysis steps characterize a multi-scale modeling technique. They represent the material design in the micro/macro-level, and accurate homogenization of the advanced composite components properties and evaluation of the resulting anisotropic characteristics and then, three-dimensionally simulate the hybrid bridge system involving all its nonlinearities. This paper investigates the performance of a new hybrid long-span cable-stayed bridge, which engages the use of advanced composite materials for the deck and the stay-cables, applying the analysis and design procedure. This design is scaled to match the general geometrical shapes, structural and aerodynamic characteristics of three of the world-longest cable-stayed bridges. What’s more, four advanced composite deck section models are proposed in this research. In order to study the performance of the referenced bridges, such as the natural frequencies, the deck top surface maximum vertical displacement, maximum Tsai-Hill failure function and the critical flutter velocity, three sets of parameters are investigated. The parameters include: (i) the micro level parameters-fiber fraction, (ii) the macro level parameters-Laminas Dominant Fiber Alignment and Laminate Thickness and (iii) the structure level parameters- cable radius.

508 斜張橋-ケーブル連成系の振動挙動におけるケーブル諸元の影響に関する基礎検討(GS-10 振動解析(2))

508 斜張橋-ケーブル連成系の振動挙動におけるケーブル諸元の影響に関する基礎検討(GS-10 振動解析(2))

Spatial Mechanical Behavior Research of Cable Anchorage Zone of Special-Shaped Steel Box Concrete Tower

In order to grasp the force performance and stress distribution of shaped pylon steel anchor box under the action of the cable tension, with a main span of 555m length of three towers cable-stayed and self-anchored suspension combined system bridge as the engineering background, through the APDL command stream parametric programming, the different finite element models of pylon steel anchor box is established by the spatial solid element and shell element, the mechanical properties of cable-pylon anchorage zone were studied under the most unfavorable load combination, considering the stress state and distribution characteristics of steel anchor box under different orthodontic force. The results showed that: under the most unfavorable combination of loads, the stress was concentrated at the position of the anchor plate and pressure plate using the initial strain mode; the calculation results of solid element and shell element were consistent by uniform loading mode, which could reflect the real stress state of steel anchor box, but the shell element corner contact area prone to stress calculation distortion.

Spatial Mechanical Behavior Research of Cable-Pylon Anchorage Zone of Steel Box Concrete Tower

In order to grasp the force performance and stress distribution of shaped pylon steel anchor box under the action of the cable tension, with a main span of 555m length of three towers cable-stayed and self-anchored suspension combined system bridge as the engineering background, through the ANSYS APDL command stream parametric programming, the different finite element models of pylon steel anchor box is established by the spatial solid element and shell element, the mechanical properties of cable-pylon anchorage zone were studied under the most unfavorable load combination, considering the stress state and distribution characteristics of steel anchor box under different orthodontic force. The results showed that, under the most unfavorable combination of loads, the stress was concentrated at the position of the anchor plate and pressure plate using the initial strain mode; the calculation results of solid element and shell element were consistent by uniform loading mode, which could reflect the real stress state of steel anchor box, but the shell element corner contact area prone to stress calculation distortion. The results provide the basis for the design and have some design reference value for the design of the same type bridge.

Dynamic Properties Analysis for Self-Anchored Suspension and Cable-Stayed Combination System Bridge

In view that dynamics research for self-anchored suspension and cable-stayed combination system bridge lags behind the practical application, this thesis analyzed its dynamic properties and seismic responses. By means of constructing a dynamic finite element model of the bridge for the dynamic properties and seismic response analysis, the thesis discovered the dynamic properties and the seismic responses laws of self-anchored suspension and cable-stayed combination system bridge. The dynamic finite element model was constructed based on the dynamic analysis theory and method, under the background of the first self-anchored suspension and cable-stayed combination system bridge in the world, and it was verifyed by on-site vibration test. The dynamic properties and the seismic responses laws provides a valuable reference for the design and maintenance of this type of bridge.

Analysis of Mechanical Behaviors of a Single Pylon Cable-Stayed and Continuous Rigid-Frame Composite Bridge

Xijiang River Bridge is the first hybrid railway bridge composed of single pylon cable-stayed and continuous rigid-frame system in China. To study the mechanical behaviors of the novel bridge, 3-D finite element model (FEM) based on Midas/Civil software is created; spatial effect of stayed cable is discussed; the self-vibration behavior of this unique bridge is analyzed by adopting the subspace iteration method; then by means of simulating analysis of the whole construction process, stress paths of critical parts in different construction stages are calculated and presented to study its mechanical behaviors. Results reveal that the composite bridge embodies features of both traditional cable-stayed bridge and rigid-frame bridge. Further study, however, shows that the unique hybrid system is mostly characterized by the rigid-frame type, meanwhile, as safety storage, the stay cable will play an important role in the “stiffness kept” of the whole structure, improving the actual stress and working condition of the whole structure in the long run.

Limit span of self-anchored cable-stayed suspension cooperation system bridge based on strength

The limit span of self-anchored cable-stayed suspension bridge is deduced. The relations among the geometrical parameters, loads and material characteristics are also analyzed. Based on the material strength and commonly used materials, the limit spans of self-anchored cable-stayed suspension bridges with concrete girder or steel girder under vertical static load are discussed in detail. The corresponding upper limit spans and the effect of the factors on the span are given. The results indicate that increasing rise-span ratio, height-span ratio and cable-stayed segment length or reducing the second dead load could increase the cooperation system span.

Nonlinear F.E. analysis of Montreal Olympic Stadium roof under natural loading conditions

The roof over the Montreal Stadium is composed of a pre-tensioned membrane combined with an eccentric cable-stayed system, i.e. the structure is non-symmetric, which leads to a non-uniform structural response under variable static loads. The Montreal Stadium roof is modelled by finite element method as a three-dimensional structure, accounting for geometrically non linear behaviour. The paper begins by analyzing the free vibrations of the structure, then goes on to consider the static as well as the dynamic effects of wind and snow. The loads induced by wind are simulated as deformation-dependent forces, i.e. follower loads. These analyses enable the structural mechanisms that caused the failure of the roof membrane to be described and better understood. In particular, the paper deals with the first failure, which occurred in an apparently unexceptional condition of wind velocity.

Nagisa Bridge, Aomori Prefecture, Japan

The Nagisa bridge in Japan is the first hybrid prestressed concrete (PC) cable-stayed and steel cable-suspended bridge in the world. The single-span footbridge was constructed over the Nakamura river. It comprises a combination of prestressed concrete deck and steel deck and a combination of cable-stayed system and suspension system supported by two towers and two anchors. The hybrid system allowed engineers to construct PC bridges with longer spans. Details are given of the design and hybrid bridge features and of the towers and anchorages, decks, cable layouts, joint between the PC and steel decks, and construction process. The bridge is subjected to cold, strong winds and salt attack. A water-cement ratio of under 40% was chosen for the concrete to increase durability. The coatings used to protect the structures from salt attack are described. Details are given of the owner, designer, contractor, costs and service date.

OVM type parallel steel strand cable-stayed system

OVM type parallel steel strand cable-stayed system

Nonlinear analysis of cable-stayed bridges at ultimate load level

Cable-stayed bridges have unique characteristics which require unique treatment in their analysis, design, and construction. This paper discusses some of these characteristics and presents proposed means of solving the associated problems. The paper discusses the nonlinear behaviour of the cable-stayed system, the load factors required for the analysis of that type of bridge, the manner of application of the loads, and the analysis under factored loads. The paper presents the results of the analysis of the ALRT cable-stayed bridge in Vancouver, Canada. Key words: cable-stayed, bridges, nonlinear, load factor, safety index.

Cable-Stayed Versus Classical Suspension Bridge

The development of cable-stayed bridges is traced back to the 1600's. The cable-stayed bridge is a new type of bridge concept that has just started to attract the attention of bridge engineers in the United States. A comparative study of existing bridges has shown that cable-stayed bridges have a definite place in the economical design of bridges for intermediate spans and challenge the supremacy of the conventional suspension bridge in the long-span range. A comparison between classical suspension and cable-stayed is presented on the basis of stiffness, optimization of cable-weight, and aerodynamics. A general conclusion is stated that a cable-stayed system is stiffer and more economical than a suspension system of camparable span. Wind effects have been investigated very thoroughly for suspension bridges and such analysis is also required for cable-stayed bridges. It is indicated that because of inherent system stiffness and damping, the cable-stayed system is not as sensitive to wind oscillation as a conventional suspension system.