Effect of Diaphragms on Load Distribution of Prestressed Concrete Bridges

2002 ◽  
Vol 1814 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Chun S. Cai ◽  
Mohsen Shahawy ◽  
Robert J. Peterman
Keyword(s):  
Prestressed Concrete ◽  
Load Distribution ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges

Diagnostic Load Tests of a Prestressed Concrete Bridge Damaged by Overheight Vehicle Impact

2000 ◽  
Vol 1696 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Francesco M. Russo ◽  
Terry J. Wipf ◽  
F. Wayne Klaiber
Keyword(s):  
Prestressed Concrete ◽  
Load Distribution ◽  
Significant Loss ◽  
Concrete Bridges ◽  
Load Testing ◽  
Prestressed Concrete Bridges ◽  
Load Tests ◽  
Damaged Beams ◽  
Remaining Capacity ◽  
Live Load Distribution

A series of diagnostic load tests performed on two prestressed concrete bridges located in western Iowa are discussed. The bridges are dual prestressed concrete I-beam structures. In June 1996, an overheight vehicle struck the westbound structure and caused significant loss of section and cracking. As a result of the severity of the damage and because of concerns about the remaining capacity and long-term durability of the damaged beams, the Iowa Department of Transportation decided to remove the two most severely damaged beams. The diagnostic load-testing portion of the research program consisted of positioning test vehicles of known weight at predetermined locations along the deck of the damaged westbound and undamaged eastbound bridge. Single-and dual-truck tests were conducted on each bridge. Following replacement of the damaged beams in the westbound structure, additional tests were conducted. The results of these three load tests are compared to determine the effect of the localized beam damage on the overall live load distribution pattern in the bridge. The objective of this research is to determine the effects of damage on the load distribution and the remaining strength of damaged prestressed concrete bridges. Noticeable differences in response were detected in the westbound and eastbound bridges before beam replacement, with the difference essentially disappearing after the repair of the westbound bridge. The research project also involved model bridge testing, along with the repair of the beams that were removed from service and those that were intentionally damaged in the laboratory. The project is now complete.

Reliability Analysis of Prestressed Concrete Bridges in Mexico: Assessment and Live Load Factors Proposal

2021 ◽  
Author(s):  
Rolando Salgado-Estrada ◽  
Sergio A. Zamora-Castro ◽  
Agustín L. Herrera-May ◽  
Yessica A. Sánchez-Moreno ◽  
Yair S. Sánchez-Moreno
Keyword(s):  
Reliability Analysis ◽  
Prestressed Concrete ◽  
Concrete Bridges ◽  
Live Load ◽  
Prestressed Concrete Bridges ◽  
Load Factors

Flexural Vibration of Prestressed Concrete Bridges with Corrugated Steel Webs

2017 ◽  
Vol 17 (02) ◽  
pp. 1750023 ◽  
Author(s):  
Xia-Chun Chen ◽  
Zhen-Hu Li ◽  
Francis T. K. Au ◽  
Rui-Juan Jiang
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Prestressed Concrete ◽  
Natural Frequencies ◽  
Sandwich Beam ◽  
Flexural Vibration ◽  
Concrete Bridges ◽  
Mode Shapes ◽  
Beam Model ◽  
Prestressed Concrete Bridges

Prestressed concrete bridges with corrugated steel webs have emerged as a new form of steel-concrete composite bridges with remarkable advantages compared with the traditional ones. However, the assumption that plane sections remain plane may no longer be valid for such bridges due to the different behavior of the constituents. The sandwich beam theory is extended to predict the flexural vibration behavior of this type of bridges considering the presence of diaphragms, external prestressing tendons and interaction between the web shear deformation and flange local bending. To this end, a [Formula: see text] beam finite element is formulated. The proposed theory and finite element model are verified both numerically and experimentally. A comparison between the analyses based on the sandwich beam model and on the classical Euler–Bernoulli and Timoshenko models reveals the following findings. First of all, the extended sandwich beam model is applicable to the flexural vibration analysis of the bridges considered. By letting [Formula: see text] denote the square root of the ratio of equivalent shear rigidity to the flange local flexural rigidity, and L the span length, the combined parameter [Formula: see text] appears to be more suitable for considering the diaphragm effect and the interaction between the shear deformation and flange local bending. The diaphragms have significant effect on the flexural natural frequencies and mode shapes only when the [Formula: see text] value of the bridge falls below a certain limit. For a bridge with an [Formula: see text] value over a certain limit, the flexural natural frequencies and mode shapes obtained from the sandwich beam model and the classical Euler–Bernoulli and Timoshenko models tend to be the same. In such cases, either of the classical beam theories may be used.

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