scholarly journals Concepts and new perspectives for long span bridges

2016 ◽  
Vol 5 (1) ◽  
pp. 75-97
Author(s):  
Fabio Brancaleoni
Keyword(s):  
Conceptual Design ◽  
Present State ◽  
Critical Parameter ◽  
State Of The Art ◽  
Span Length ◽  
Factors Affecting ◽  
Long Span Bridges ◽  
Future Developments ◽  
Long Span ◽  
The Subject

AbstractA discussion of the dominant factors affecting the behaviour of long span cable supported bridges is the subject of this paper. The main issue is the evolution of properties and response of the bridge with the size of the structure, represented by the critical parameter of span length, showing how this affects the conceptual design. After a review of the present state of the art, perspectives for future developments are discussed.

Introduction and State of the Art

1978 ◽  
Vol 36 (3) ◽  
pp. 163-172
Author(s):  
V.E. Cosslett
Keyword(s):  
Electron Microscopy ◽  
Present State ◽  
State Of The Art ◽  
Cavendish Laboratory ◽  
Future Developments ◽  
Retrospective View ◽  
Present Generation ◽  
The Subject

The invitation to give this opening survey included the suggestion to say something about past as well as future developments, about yesterday as well as tomorrow. A retrospective view is in any event obligatory if the present state of the subject is to be properly displayed, and I am happy to adopt this approach. It happens that recently we added an original RCA type EMB instrument to our historical collection in the Cavendish Laboratory, that goes back through Bragg and Eutherford to Thomson, Eayleigh and Maxwell. My first experience of electron microscopy was in fact gained on the EMB, and soon afterwards on the 1940 Siemens UM100. So I thought it would be interesting to compare the present generation of microscopes with those old originals.

History of Mathematics in the Islamic World: The Present State of the Art

1985 ◽  
Vol 19 (1) ◽  
pp. 9-33 ◽  
Author(s):  
J. L. Berggren
Keyword(s):  
Present State ◽  
State Of The Art ◽  
History Of Mathematics ◽  
Islamic Culture ◽  
Islamic World ◽  
History Of ◽  
The Subject ◽  
Mathematical Sciences ◽  
Islamic Mathematics

In Recent Years, many discoveries in the history of Islamic mathematics have not been reported outside the specialist literature, even though they raise issues of interest to a larger audience. Thus, our aim in writing this survey is to provide to scholars of Islamic culture an account of the major themes and discoveries of the last decade of research on the history of mathematics in the Islamic world. However, the subject of mathematics comprised much more than what a modern mathematician might think of as belonging to mathematics, so our survey is an overview of what may best be called the “mathematical sciences” in Islam; that is, in addition to such topics as arithmetic, algebra, and geometry we will also be interested in mechanics, optics, and mathematical instruments.

What is Happening in Classical Indology?—A Review Article

1982 ◽  
Vol 41 (2) ◽  
pp. 269-291 ◽  
Author(s):  
Frits Staal
Keyword(s):  
Central Asia ◽  
Present State ◽  
Indian Philosophy ◽  
State Of The Art ◽  
Review Article ◽  
Article Deal ◽  
The Subject

Most of the books reviewed in this article deal with Indian philosophy, mythology, or the Vedas, but other recent publications are discussed. The author provides a general assessment of the present state of the art in classical Indology. In spite of the venerable antiquity of the subject, not all pertinent studies are esoteric or dull. There have been new and unexpected discoveries along with solid and original contributions that have wide-ranging implications. Many views that are commonly held are now seen to derive from misconceptions and to stand in need of revision. Topics treated are Hinduism, Buddhism, Jainism, Tantrism, and Shamanism; contacts between India and Central Asia, and the Indianization of Asia; Soma andkarma; ritual, epic, psychology, sex, and grammar.

scholarly journals State-of-the-Art Review on Determining Prestress Losses in Prestressed Concrete Girders

2020 ◽  
Vol 10 (20) ◽  
pp. 7257
Author(s):  
Marco Bonopera ◽  
Kuo-Chun Chang ◽  
Zheng-Kuan Lee
Keyword(s):  
Prestressed Concrete ◽  
State Of The Art ◽  
Nondestructive Method ◽  
Prestress Loss ◽  
Prestress Losses ◽  
Long Span Bridges ◽  
Concrete Girders ◽  
Long Span ◽  
Vibration Responses ◽  
Prestressed Concrete Girders

Prestressing methods were used to realize long-span bridges in the last few decades. For their predictive maintenance, devices and dynamic nondestructive procedures for identifying prestress losses were mainly developed since serviceability and safety of Prestressed Concrete (PC) girders depend on the effective state of prestressing. In fact, substantial long term prestress losses can induce excessive deflections and cracking in large span PC bridge girders. However, old unsolved problematics as well as new challenges exist since a variation in prestress force does not significantly affect the vibration responses of such PC girders. As a result, this makes uncertain the use of natural frequencies as appropriate parameters for prestress loss determinations. Thus, amongst emerging techniques, static identification based on vertical deflections has preliminary proved to be a reliable method with the goal to become a dominant approach in the near future. In fact, measured vertical deflections take accurately and instantaneously into account the changes of structural geometry of PC girders due to prestressing losses on the equilibrium conditions, in turn caused by the combined effects of tendon relaxation, concrete creep and shrinkage, and parameters of real environment as, e.g., temperature and relative humidity. Given the current state of quantitative and principled methodologies, this paper represents a state-of-the-art review of some important research works on determining prestress losses conducted worldwide. The attention is principally focused on a static nondestructive method, and a comparison with dynamic ones is elaborated. Comments and recommendations are made at proper places, while concluding remarks including future studies and field developments are mentioned at the end of the paper.

Structural Type Selection for Long-Span Bridges in Mountain Area

2012 ◽  
Vol 256-259 ◽  
pp. 1596-1600
Author(s):  
Dong Liang ◽  
Chang Rong Yao ◽  
Sai Zhi Liu
Keyword(s):  
Conceptual Design ◽  
Structural Type ◽  
Mountainous Area ◽  
Construction Technology ◽  
Mountain Area ◽  
Long Span Bridges ◽  
Long Span ◽  
Type Selection ◽  
Geological Conditions ◽  
Bridge Structures

As the western region is a mountainous area with geology complicated geological conditions, the proportion of bridges and tunnels is bigger. Based on the characteristic of mountainous route and long-span bridges, this paper discussed the conceptual design of mountainous bridges. Firstly, this paper analyzes the characteristic of mountainous long-span bridges and proposed some fundamental principles to design long-span bridges. After the comparison of the main bridge structures, the paper points out that the designer should select the best programs considering hydrological, geological, geomorphology, construction technology, transportation , geographical environment and social environment. The purpose of this paper is to give reference for the conceptual design of mountainous long-span bridges.

scholarly journals Dynamic response of long-span bridges subjected to nonuniform excitation: a state-of-the-art review

2019 ◽  
Vol 258 ◽  
pp. 05017
Author(s):  
Seplika Yadi ◽  
Bambang Suhendro ◽  
Henricus Priyosulistyo ◽  
Akhmad Aminullah
Keyword(s):  
Dynamic Response ◽  
State Of The Art ◽  
Ground Motions ◽  
Experimental Studies ◽  
Suspension Bridges ◽  
Long Span Bridges ◽  
Long Span ◽  
Numerical Studies ◽  
Multiple Support ◽  
Support Excitation

In recent years, considerable attention has been paid to the research of dynamic response of long-span bridges with particular emphasis on seismic behavior. Cable-stayed and suspension bridges are the most popular types. Since long-span bridges have multi-supports and extreme lengths, due to the spatial variation effects, the ground motions at different supports might be non-uniform. A state-of-the-art update review of the response of long-span bridges subjected to non-uniform excitation is presented. The review mainly focuses on the theoretical aspects of non-uniform excitation, numerical studies, and experimental studies to verify some of the theoretical findings. In this paper, a review of the use of shake-table in experimental studies of long-span bridges is also presented. The non-uniform cases considered include a time delay with the same support excitations, multiple support excitations, and the combination of the first and the later. The results are discussed and summarized in comparison to the cases of uniform support excitation.

Fields, and methods of their simulation and exploration

SIMULATION ◽  
1967 ◽  
Vol 8 (3) ◽  
pp. 151-164
Author(s):  
Avrum Soudack ◽  
C.A. Edward Uhlig
Keyword(s):  
Elastic Stress ◽  
State Of The Art ◽  
Rotational Symmetry ◽  
Dielectric Constants ◽  
New Techniques ◽  
Electric Power Engineering ◽  
Future Developments ◽  
General Field ◽  
Specialized Section ◽  
The Subject

Since the treatment of the general field concept seems to be missing in the literature, and since methods of field ex ploration and of simulation are scattered in a great number of domestic as well as foreign papers, this paper presents, first, a brief survey on fields and on methods of their analy sis and simulation, and then reports on the state of the art in the area of simulation of electrostatic fields by means of a conductive-sheet analog or electrolytic tank. Although the paper has been written primarily with the needs of electric power engineering in mind, the treatment of the subject has been held as interdiscipli nary as possible. The paper will thus be useful also to those working in aerodynamics, elastic stress analysis, heat transfer, astronomy, acoustics, atomic physics, and ma terial sciences. Furthermore, for the electrical engineer, it may be helpful to know that electrical problems sometimes may be solved more easily or more conveniently by the use of nonelectrical methods. In the specialized section on the application of the electrolytic tank and the conductive-sheet analog to the solution of electrostatic field problems, little-known as well as new techniques are discussed, such as (1) plotting of infinite fields on a double analog, (2) determining of force lines or surfaces by means of the dual analog, (3) simulation of areas of different dielectric constants and of continuously variable dielectric constants by means of jellified dielectrics, (4) plotting of areas of low current density by the use of consecutive field mapping, (5) the possibility of plotting fields with rotational symmetry on isotropically conducting sheets and graphically transpos ing the map so obtained, and (6) solution of distributed source problems. A comparison of advantages, disadvantages, and limita tions of the electrolytic tank method and the conductive sheet analog is also presented. Finally, an appeal is made for teaching and use of field analog methods for future developments.

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