Dynamic Amplification Factors in Cable-stayed Structures

The aim of this paper is to demonstrate that in cable-stayed structures dynamic amplification factors caused by the sudden breakage of cables can be larger than 2. This fact is extremely important since design guidelines for cable-stayed bridges indicate that the highest value for such factors is 2, whereas under certain circumstances that value could be considered unsafe. We set out the conditions that lead to that value being surpassed. We also show that the dynamic amplification factors related to deflections are lower than those related to bending moments and that the latter are in turn lower than those related to shear forces. Two examples are given: one involving the abrupt application of loads to a simply supported beam and the other the accidental breakage of a stay cable in a bridge with under-deck cable-staying.

[1]  David P. Thambiratnam,et al.  Free vibration analysis of bridges , 1995 .

[2]  J. L. Humar,et al.  Dynamic response of bridges under travelling loads , 1993 .

[3]  David P. Thambiratnam,et al.  Dynamic response of a curved bridge under moving truck load , 2002 .

[4]  Masatsugu Nagai,et al.  Structural Characteristics of a Cable-Trussed Bridge , 2001 .

[5]  Mark F. Green.  Discussion: Bridge dynamics and dynamic amplification factors — a review of analytical and experimental findings , 1993 .

[6]  Omar Chaallal,et al.  Bridge dynamics and dynamic amplification factors — a review of analytical and experimental findings , 1992 .

[7]  Mario Fafard,et al.  Analyse dynamique de l'interaction pont-véhicules pour les ponts routiers. II. Application au pont de Senneterre au Québec , 1998 .

[8]  Gouri Dhatt,et al.  DYNAMIC BEHAVIOUR OF MULTI-SPAN BEAMS UNDER MOVING LOADS , 1997 .

[9]  J. L. Urrutia-Galicia.  AMPLIFICATION FACTORS OF BEAMS UNDER THE ACTION OF MOVING POINT FORCES , 1994 .

[10]  É. Savin.  DYNAMIC AMPLIFICATION FACTOR AND RESPONSE SPECTRUM FOR THE EVALUATION OF VIBRATIONS OF BEAMS UNDER SUCCESSIVE MOVING LOADS , 2001 .

[11]  J. M. Stallings,et al.  Live-Load Response of Alabama’s High-Performance Concrete Bridge , 2003 .

[12]  Patrick Paultre,et al.  Dynamic Testing Procedures for Highway Bridges Using Traffic Loads , 1995 .

[13]  Ian P.T. Firth,et al.  Cable-stayed bridges—Recent developments and their future: Proceedings of the Seminar, Yokohama, Japan, 10–11 December, 1991, eds. Manabu Ito, Yozo Fujino, Toshio Miyata and Nobuyuki Narita, Elsevier, Amsterdam, 1991 , 1992 .

[14]  M. Link,et al.  Phenomena and evaluation of dynamic structural responses , 1996 .

[15]  René Walther,et al.  Cable stayed bridges , 1988 .

[16]  Mo Shing Cheung,et al.  Dynamic performance of the Confederation Bridge due to traffic and wind , 2004 .

[17]  Esko Järvenpää,et al.  Cable-stayed bridges, effect of breaking of a cable , 1994 .

[18]  K. E. Akoussah,et al.  Étude paramétrique du facteur d'amplification dynamique des charges pour des ponts à travée simple en béton armé , 1997 .

[19]  Mike Schlaich,et al.  The Glacis Bridge in Ingolstadt, Germany – Design and Construction , 2001 .

[20]  Jaap Wardenier,et al.  Dynamic amplification factors and EUDL of bridges under random traffic flows , 2001 .

[21]  Eugen Brühwiler,et al.  Closure of "Dynamic Behavior of Deck Slabs of Concrete Road Bridges" , 2004 .