The Experts below are selected from a list of 20373 Experts worldwide ranked by ideXlab platform
Wei Haoyang - One of the best experts on this subject based on the ideXlab platform.
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study of different construction processes affecting the installation of appropriate cambers for long span railway Cable Stayed Bridges
Mathematical Models and Methods in Applied Sciences, 2013Co-Authors: Chen Zengshun, Zhang Cheng, Huang Guanrong, Wei HaoyangAbstract:There are few studies on the installation of appropriate cambers for long-span railway Cable-Stayed Bridges at home and abroad. This article describes the influential factors of thte installation of cambers, and analyses its theories and approaches, as well as takes use of design formula for appropriate camber installation. Combining project cases of long-span railway Cable-Stayed Bridges, and exploiting FEM software-Midas civil2010, the article has an analytic study on effects of different construction processes on camber installation, which is the basis of installing cambers of such Bridges in the future.
Alfredo Camara - One of the best experts on this subject based on the ideXlab platform.
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Seismic Behaviour of Cable-Stayed Bridges: A Review
MOJ Civil Engineering, 2018Co-Authors: Alfredo CamaraAbstract:Cable-Stayed Bridges represent backbones in the infrastructure networks and their adequate seismic response must be ensured. These structures present complex interactions between the deck, the Cables, the towers and their foundation. This, in combination with the reduced damping and the outstanding slenderness of Cable-Stayed Bridges, renders a unique dynamic response. A complete review on the state of knowledge about the seismic behaviour of Cable-Stayed Bridges is presented here, with special attention to the analysis techniques. The current design trends in the seismic design and control of Cable-Stayed Bridges are also presented.
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design of hysteretic dampers with optimal ductility for the transverse seismic control of Cable Stayed Bridges
Earthquake Engineering & Structural Dynamics, 2017Co-Authors: Alfredo Camara, Miguel A Astiz, Roberto Cristantielli, C MalagachuquitaypeAbstract:Cable-Stayed Bridges require a careful consideration of the lateral force exerted by the deck on the towers under strong earthquakes. This work explores the seismic response of Cable-Stayed Bridges with yielding metallic dampers composed of triangular plates that connect the deck with the supports in the transverse direction. A design method based on an equivalent single-degree of freedom approximation is proposed. This is proved valid for conventional Cable-Stayed Bridges with 200- and 400-m main spans, but not 600 m. The height of the plates is chosen to (1) achieve a yielding capacity that limits the maximum force transmitted from the deck to the towers, and to (2) control the hysteretic energy that the dampers dissipate by defining their design ductility. In order to select the optimal ductility and the damper configuration, a multi-objective response factor that accounts for the energy dissipation, peak damper displacement and low-cycle fatigue is introduced. The design method is applied to Cable-Stayed Bridges with different spans and deck–support connections. The results show that the dissipation by plastic deformation in the dampers prevents significant damage in the towers of the short-to-medium-span Bridges under the extreme seismic actions. However, the transverse response of the towers in the bridge with a 600-m main span is less sensitive to the dampers.
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fundamental mode estimation for modern Cable Stayed Bridges considering the tower flexibility
Journal of Bridge Engineering, 2014Co-Authors: Alfredo Camara, Miguel A AstizAbstract:The design of Cable-Stayed Bridges is typically governed by the dynamic response. This work provides designers with essential information about the fundamental vibration modes, proposing analytical expressions based on the mechanical and geometrical properties of the structure. Different bridge geometries are usually considered in the early design stages until the optimum solution is defined. In these design stages, the analytical formulation is advantageous, because finite-element models are not required and modifying the bridge characteristics is straightforward. The influence of the tower flexibility is included in this study, unlike in previous attempts on mode estimation. The dimensions and proportions of the canonical models proposed in the analytical study stem from the previous compilation of the dimensions of a large number of constructed Cable-Stayed Bridges. Five tower shapes, central or lateral Cable-system layouts and box- or U-shaped deck sections, have been considered. The vibration properties of more than 1,000 Cable-Stayed Bridges with main spans ranging from 200 to 800 m long were extracted within an extensive parametric analysis. The Vaschy-Buckingham theorem of dimensional analysis was applied to the numerical results to propose the formulation for period estimation. Finally, the formulas were validated with the vibration properties of 17 real Cable-Stayed Bridges constructed in different countries. The importance of the tower flexibility is verified, and the errors observed are typically below 15%, significantly improving the estimations obtained by previous research works.
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pushover analysis for the seismic response prediction of Cable Stayed Bridges under multi directional excitation
Engineering Structures, 2012Co-Authors: Alfredo Camara, Miguel A AstizAbstract:Cable-Stayed Bridges represent nowadays key points in transport networks and their seismic behavior needs to be fully understood, even beyond the elastic range of materials. Both nonlinear dynamic (NL-RHA) and static (pushover) procedures are currently available to face this challenge, each with intrinsic advantages and disadvantages, and their applicability in the study of the nonlinear seismic behavior of Cable-Stayed Bridges is discussed here. The seismic response of a large number of finite element models with different span lengths, tower shapes and class of foundation soil is obtained with different procedures and compared. Several features of the original Modal Pushover Analysis (MPA) are modified in light of Cable-Stayed bridge characteristics, furthermore, an extension of MPA and a new coupled pushover analysis (CNSP) are suggested to estimate the complex inelastic response of such outstanding structures subjected to multi-axial strong ground motions.
Jose Turmo - One of the best experts on this subject based on the ideXlab platform.
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effects in service of the staggered construction of Cable Stayed Bridges built on temporary supports
Baltic Journal of Road and Bridge Engineering, 2015Co-Authors: Jose Antonio Lozanogalant, Ignacio Payazaforteza, Jose TurmoAbstract:Cable-Stayed Bridges can be rarely built on a single construction stage and staggered construction is commonly used. The effects of this staggered construction are not only economical as they might also play an important role in the structural behaviour in service. Despite of this importance, these effects are rarely included into the definition of the structural response in service. In order to fill this gap, this paper deals with the effects in service of the staggered erection of steel Cable-Stayed Bridges built on temporary supports. To do so, a criterion based on the minimization of the bending energy in terms of stay forces is applied to several Cable-Stayed Bridges. This study shows the importance of the existence of the pylon-deck connection as well as the number and location of both construction joints and temporary supports during staggered erection.
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Creep and shrinkage effects in service stresses of concrete Cable-Stayed Bridges
Computers and Concrete, 2014Co-Authors: Jose Antonio Lozano-galant, Jose TurmoAbstract:Most of the methods presented in the literature to define the target service stresses (Objective Service Stage, OSS) of Cable-Stayed Bridges rarely include the time-dependent phenomena effects. Nevertheless, especially in concrete structures, this assumption might be on the unsafe side because time-dependent phenomena usually modify service stresses. To fill this gap, this paper studies the time-dependent phenomena effects into service stresses of concrete Cable-Stayed Bridges. After illustrating the important role of these phenomena in an asymmetrical Cable-Stayed bridge without backstay, a new method to include their effects into the OSS is presented. An important issue to be considered in this method is the target time in which the OSS is defined to be achieved. The application of this method to two different structures showed the convenience of defining the OSS to be achieved at early times because that way the envelope of service stresses is reduced.
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direct simulation of the tensioning process of Cable Stayed Bridges
Computers & Structures, 2013Co-Authors: Jose Antonio Lozanogalant, Ignacio Payazaforteza, Xu Dong, Jose TurmoAbstract:This paper proposes a new and innovative algorithm, the Direct Algorithm (DA), which introduces, for the very first time, the unstressed length of the stays concept into the modeling of the construction process of Cable-Stayed Bridges. This assumption enables a fast and direct simulation of construction stages by analyzing independent Finite Element Models when time-dependent phenomena are neglected. The computational speed and the limited computer storing requirements of the DA make it especially indicated for optimization problems. Furthermore, it can be implemented in any structural analysis software.
Chen Zengshun - One of the best experts on this subject based on the ideXlab platform.
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study of different construction processes affecting the installation of appropriate cambers for long span railway Cable Stayed Bridges
Mathematical Models and Methods in Applied Sciences, 2013Co-Authors: Chen Zengshun, Zhang Cheng, Huang Guanrong, Wei HaoyangAbstract:There are few studies on the installation of appropriate cambers for long-span railway Cable-Stayed Bridges at home and abroad. This article describes the influential factors of thte installation of cambers, and analyses its theories and approaches, as well as takes use of design formula for appropriate camber installation. Combining project cases of long-span railway Cable-Stayed Bridges, and exploiting FEM software-Midas civil2010, the article has an analytic study on effects of different construction processes on camber installation, which is the basis of installing cambers of such Bridges in the future.
C Malagachuquitaype - One of the best experts on this subject based on the ideXlab platform.
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design of hysteretic dampers with optimal ductility for the transverse seismic control of Cable Stayed Bridges
Earthquake Engineering & Structural Dynamics, 2017Co-Authors: Alfredo Camara, Miguel A Astiz, Roberto Cristantielli, C MalagachuquitaypeAbstract:Cable-Stayed Bridges require a careful consideration of the lateral force exerted by the deck on the towers under strong earthquakes. This work explores the seismic response of Cable-Stayed Bridges with yielding metallic dampers composed of triangular plates that connect the deck with the supports in the transverse direction. A design method based on an equivalent single-degree of freedom approximation is proposed. This is proved valid for conventional Cable-Stayed Bridges with 200- and 400-m main spans, but not 600 m. The height of the plates is chosen to (1) achieve a yielding capacity that limits the maximum force transmitted from the deck to the towers, and to (2) control the hysteretic energy that the dampers dissipate by defining their design ductility. In order to select the optimal ductility and the damper configuration, a multi-objective response factor that accounts for the energy dissipation, peak damper displacement and low-cycle fatigue is introduced. The design method is applied to Cable-Stayed Bridges with different spans and deck–support connections. The results show that the dissipation by plastic deformation in the dampers prevents significant damage in the towers of the short-to-medium-span Bridges under the extreme seismic actions. However, the transverse response of the towers in the bridge with a 600-m main span is less sensitive to the dampers.