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Book Structural Behaviour of Cable Stayed Bridges Taking Into Account Time Dependent Behaviour

Download or read book Structural Behaviour of Cable Stayed Bridges Taking Into Account Time Dependent Behaviour written by Xuetong Si and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Structural Behaviour of Cable-stayed Bridges Taking Into Account Time-dependent Behaviour" by Xuetong, Si, 司学通, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The creep and shrinkage of concrete and the relaxation of cables cause long-term redistribution of internal forces and time-dependent deformations in concrete structures, steel-concrete composite structures and concrete cable-stayed bridges. They should be properly modelled for accurate prediction of their long-term behaviour and its effect on instantaneous structural responses at service. An equivalent stress relaxation model is proposed for prestressing tendons based on the intrinsic stress relaxation, from which the equivalent creep coefficients can be obtained through a recursive algorithm. Based on the equivalent stress relaxation model, an accurate finite element analysis of time-dependent behaviour by time integration has been devised considering concrete creep, concrete shrinkage and cable relaxation. Concrete members are modelled by beam-column elements while tendons are modelled by truss elements with nodes connected to the beam axis by perpendicular rigid arms. It is found that the proposed relaxation model with time integration can provide a reliable method as well as benchmark solutions for time-dependent analysis. The numerical results obtained indicate that the interactions among these factors should be properly considered in analysing the long-term performance of concrete bridges. Although time integration provides a reliable method for time-dependent analysis, both the computing time and memory requirement increase drastically with the number of time steps as the time-dependent strains of concrete and tendons within a time interval depend on the loading history up to that time. It is therefore necessary to develop a more efficient method to conduct time-dependent analysis. The relaxation-adjusted elasticity modulus is introduced on the basis of equivalent creep coefficients of tendons. Then, an efficient tendon sub-element is put forward to cope with cables with arbitrary profiles. Finally, a more general single-step method is devised using the classical age-adjusted elasticity modulus to account for external loading and creep effect, the shrinkage-adjusted elasticity modulus to consider shrinkage effect and its interaction with concrete creep, and the relaxation-adjusted elasticity modulus to consider the effect of cable relaxation based on the finite element method. The numerical results obtained indicate not only the accuracy of the single-step method but also the significance of interaction among various time-varying factors. Based on the time integration or single-step method, a systematic method is developed to monitor the long-term variations of dynamic properties of cable-stayed bridges taking into account various time-varying factors and geometric nonlinearities. Numerical studies show that, although geometric nonlinearities tend to reduce the natural frequencies, the time-dependent behaviour of concrete more than offsets it and tends to increase the natural frequencies in the long run. A generic method is further presented to investigate the long-term dynamic response of vehicle-bridge interaction systems taking account of time-dependent behaviour. The vehicles are represented by a combination of mass-spring-damper systems while the bridge is modelled by finite elements. The surface roughness of bridge deck is simulated by spectral representation method and introduced to the coupled system properly. Based on t

Book Structural effects of time dependent behaviour of concrete

Download or read book Structural effects of time dependent behaviour of concrete written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1993-03-01 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Cable Stayed Bridges

Download or read book Cable Stayed Bridges written by Rene Walther and published by Thomas Telford. This book was released on 1999-10-27 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: An examination of all aspects of the design of cable stayed bridges. Starting with a brief history, it addresses general design criteria and technology, as well as static and dynamic analysis. The illustrations provide examples of structures already built and document their critical parameters.

Book Cable Supported Bridges

Download or read book Cable Supported Bridges written by Niels J. Gimsing and published by John Wiley & Sons. This book was released on 2011-12-30 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fourteen years on from its last edition, Cable Supported Bridges: Concept and Design, Third Edition, has been significantly updated with new material and brand new imagery throughout. Since the appearance of the second edition, the focus on the dynamic response of cable supported bridges has increased, and this development is recognised with two new chapters, covering bridge aerodynamics and other dynamic topics such as pedestrian-induced vibrations and bridge monitoring. This book concentrates on the synthesis of cable supported bridges, suspension as well as cable stayed, covering both design and construction aspects. The emphasis is on the conceptual design phase where the main features of the bridge will be determined. Based on comparative analyses with relatively simple mathematical expressions, the different structural forms are quantified and preliminary optimization demonstrated. This provides a first estimate on dimensions of the main load carrying elements to give in an initial input for mathematical computer models used in the detailed design phase. Key features: Describes evolution and trends within the design and construction of cable supported bridges Describes the response of structures to dynamic actions that have attracted growing attention in recent years Highlights features of the different structural components and their interaction in the entire structural system Presents simple mathematical expressions to give a first estimate on dimensions of the load carrying elements to be used in an initial computer input This comprehensive coverage of the design and construction of cable supported bridges provides an invaluable, tried and tested resource for academics and engineers.

Book Construction Control of Cable stayed Bridges

Download or read book Construction Control of Cable stayed Bridges written by José Antonio Lozano Galant and published by . This book was released on 2014 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a study of the simulation of cable-stayed bridges built on temporary supports focused on their response during construction and in service. To simulate the behavior during construction, a set of four different algorithms has been developed to deal with initial design (Backward Algorithm), updating the tensioning process when deviations on site are measured (Forward Algorithm), optimization processes (Direct Algorithm) and time-dependent phenomena effects (Forward-Direct Algorithm). These algorithms were validated by comparing their results with those obtained by two commercial codes. On the other hand, new criteria have been proposed to include the effects of the staggered erection of the superstructure and the time-dependent phenomena effects into the definition of the Objective Service State. To illustrate the application of these methods, a set of academic and actual structures is analyzed. For a more accurate simulation of the actual response of structures on site, a new Structural System Identification (SSI) method (Observability method) is developed. This method is based on the information provided by the monitoring of a static non-destructive test. After validating the results of this method with three alternative methods proposed in the literature, it is applied to complex structures (such as singular buildings and cable-stayed bridges). A parametric analysis is presented to illustrate the role that the uncertainty of each parameter of a real cable-stayed bridge plays in its behavior during construction and in service. Furthermore, modifications of this method to deal with damages, actual boundary conditions, temperature effects, and dynamic excitation tests are presented. The developed SSI method has also lead to the development of a very powerful mathematical tool to deal with polyrational systems of equations. This tool presents a number of applications in many fields of science and engineering (such as transportation, hydraulics or energy power distribution, among many others). To define the minimum measurement set of measurements required for an adequate system identification, a new and innovative graphical tool (observability tree) is developed. To ease the representation of these trees, a set of guidelines is proposed for beam and cable-stayed bridges. To minimize the degrees of freedom to be monitored on site for system identification with actual loads, a new application of the Maxwell's theorem has been proposed. To this end, the utilization of information from alternative load cases, boundary conditions and construction stages is also presented. The results of the proposed methods have led to significant conclusions regarding the response of the cable-stayed bridges built on temporary supports both during construction and in service as well as the importance of their construction control by SSI techniques. From these conclusions, a set of guidelines has been proposed to address the erection of the superstructure, to estimate the appropriate time to define the stay cable forces in service in concrete cable-stay bridges considering time-dependent phenomena effects, to define a measurement set for an adequate SSI and to minimize the points to be monitored.

Book High Performance and Optimum Design of Structures and Materials V

Download or read book High Performance and Optimum Design of Structures and Materials V written by S. Hernandez and published by WIT Press. This book was released on 2022-09-13 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of novel materials and new structural concepts nowadays is not restricted to highly technical areas like aerospace, aeronautical applications or the automotive industry, but affects all engineering fields including those such as civil engineering and architecture. The included contributions highlight the latest developments in design and manufacturing. Most high-performance structures require the development of a generation of new materials, which can more easily resist a range of external stimuli or react in a non-conventional manner. Particular emphasis is placed on intelligent structures and materials as well as the application of computational methods for their modelling, control and management. The book also addresses the topic of design optimisation. Contributions cover numerical methods, different optimisation techniques and new software. Optimisation problems include those related to the size, shape and topology of structures and materials. Optimisation techniques have much to offer to those involved in the design of new industrial products, as the appearance of powerful commercial computer codes has created a fertile field for the incorporation of optimisation in the design process of all engineering disciplines. The performance of structures under shock and impact loads is another area covered. The increasing need to protect civilian infrastructure and industrial facilities against unintentional loads arising from accidental impact and explosion events as well as terrorist attacks is reflected in the sustained interest worldwide. While advances have been made in recent decades, many challenges remain, such as developing more effective and efficient blast and impact mitigation approaches or assessing the uncertainties associated with large and small scale testing and validation of numerical and analytical models. The overall aim is to move towards a better understanding of the critical issues relating to the testing behaviour, modelling and analyses of protective structures against blast and impact loading. The studies contained in this volume were presented at the International Conference on High Performance and Optimum Structures and Materials Encompassing Shock and Impact Loading and address issues involving advanced types of structures, particularly those based on new concepts, and shock and impact resistance.

Book Structural Behaviour of Cable stayed Bridges

Download or read book Structural Behaviour of Cable stayed Bridges written by Davalos R. Davalos and published by . This book was released on 2000 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Time Dependent Behaviour of Concrete Structures

Download or read book Time Dependent Behaviour of Concrete Structures written by Raymond Ian Gilbert and published by CRC Press. This book was released on 2010-09-15 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Serviceability failures of concrete structures involving excessive cracking or deflection are relatively common, even in structures that comply with code requirements. This is often as a result of a failure to adequately account for the time-dependent deformations of concrete in the design of the structure. The serviceability provisions embodied in

Book Cable Vibrations in Cable stayed Bridges

Download or read book Cable Vibrations in Cable stayed Bridges written by Elsa de Sá Caetano (autor.) and published by IABSE. This book was released on 2007 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book provides a comprehensive survey on the governing phenomena of cable vibration, both associated with direct action of wind and rain: buffeting, vortex-shedding, wake effects, rain-wind vibration; and resulting from the indirect excitation through anchorage oscillation: external and parametric excitation. Methodologies for assessment of the effects of those phenomena are presented and illustrated by practical examples. Control of cable vibrations is then discussed and state-of-art results on the design of passive control devices are presented.

Book Advances in Structural and Multidisciplinary Optimization

Download or read book Advances in Structural and Multidisciplinary Optimization written by Axel Schumacher and published by Springer. This book was released on 2017-12-04 with total page 2101 pages. Available in PDF, EPUB and Kindle. Book excerpt: The volume includes papers from the WSCMO conference in Braunschweig 2017 presenting research of all aspects of the optimal design of structures as well as multidisciplinary design optimization where the involved disciplines deal with the analysis of solids, fluids or other field problems. Also presented are practical applications of optimization methods and the corresponding software development in all branches of technology.

Book Bridge Maintenance Safety Management Resilience and Sustainability

Download or read book Bridge Maintenance Safety Management Resilience and Sustainability written by Fabio Biondini and published by CRC Press. This book was released on 2012-06-21 with total page 4119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge Maintenance, Safety, Management, Resilience and Sustainability contains the lectures and papers presented at The Sixth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2012), held in Stresa, Lake Maggiore, Italy, 8-12 July, 2012. This volume consists of a book of extended abstracts (800 pp) Extensive collection of revised expert papers on recent advances in bridge maintenance, safety, management and life-cycle performance, representing a major contribution to the knowledge base of all areas of the field.

Book fib Model Code for Concrete Structures 2010

Download or read book fib Model Code for Concrete Structures 2010 written by fib - federation internationale du beton and published by John Wiley & Sons. This book was released on 2013-12-04 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Federation for Structural Concrete (fib) is a pre-normative organization. 'Pre-normative' implies pioneering work in codification. This work has now been realized with the fib Model Code 2010. The objectives of the fib Model Code 2010 are to serve as a basis for future codes for concrete structures, and present new developments with regard to concrete structures, structural materials and new ideas in order to achieve optimum behaviour. The fib Model Code 2010 is now the most comprehensive code on concrete structures, including their complete life cycle: conceptual design, dimensioning, construction, conservation and dismantlement. It is expected to become an important document for both national and international code committees, practitioners and researchers. The fib Model Code 2010 was produced during the last ten years through an exceptional effort by Joost Walraven (Convener; Delft University of Technology, The Netherlands), Agnieszka Bigaj-van Vliet (Technical Secretary; TNO Built Environment and Geosciences, The Netherlands) as well as experts out of 44 countries from five continents.

Book Structural Dynamics

Download or read book Structural Dynamics written by Harry Grundmann and published by CRC Press. This book was released on 2002 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings contain contributions presented by authors from more than 30 countries at EURODYN 2002. The proceedings show recent scientific developments as well as practical applications, they cover the fields of theory of vibrations, nonlinear vibrations, stochastic dynamics, vibrations of structured elements, wave propagation and structure-borne sound, including questions of fatigue and damping. Emphasis is laid on vibrations of bridges, buildings, railway structures as well as on the fields of wind and earthquake engineering, repectively. Enriched by a number of keynote lectures and organized sessions the two volumes of the proceedings present an overview of the state of the art of the whole field of structural dynamics and the tendencies ot its further development.