Evaluation of live-load distribution factors for high-performance prestressed concrete girder bridges

2019 ◽  
Vol 15 (1-2) ◽  
pp. 15-26
Author(s):  
Hazim Dwairi ◽  
Omar Al-Hattamleh ◽  
Husam Al-Qablan
Keyword(s):  
Prestressed Concrete ◽  
Load Distribution ◽  
High Performance ◽  
Live Load ◽  
Girder Bridges ◽  
Live Load Distribution Factors ◽  
Live Load Distribution ◽  
Load Distribution Factors ◽  
Concrete Girder

scholarly journals Live Load Distribution Factors for Skew Stringer Bridges with High-Performance-Steel Girders under Truck Loads

2018 ◽  
Vol 8 (10) ◽  
pp. 1717 ◽  
Author(s):  
Iman Mohseni ◽  
Yong Cho ◽  
Junsuk Kang
Keyword(s):  
Load Distribution ◽  
Shear Force ◽  
High Performance ◽  
Structural Parameters ◽  
Highway Bridges ◽  
Live Load ◽  
High Performance Steel ◽  
Live Load Distribution Factors ◽  
Live Load Distribution ◽  
Load Distribution Factors

Because the methods used to compute the live load distribution for moment and shear force in modern highway bridges subjected to vehicle loading are generally constrained by their range of applicability, refined analysis methods are necessary when this range is exceeded or new materials are used. This study developed a simplified method to calculate the live load distribution factors for skewed composite slab-on-girder bridges with high-performance-steel (HPS) girders whose parameters exceed the range of applicability defined by the American Association of State Highway and Transportation Officials (AASHTO)’s Load and Resistance Factor Design (LRFD) specifications. Bridge databases containing information on actual bridges and prototype bridges constructed from three different types of steel and structural parameters that exceeded the range of applicability were developed and the bridge modeling verified using results reported for field tests of actual bridges. The resulting simplified equations for the live load distribution factors of shear force and bending moment were based on a rigorous statistical analysis of the data. The proposed equations provided comparable results to those obtained using finite element analysis, giving bridge engineers greater flexibility when designing bridges with structural parameters that are outside the range of applicability defined by AASHTO in terms of span length, skewness, and bridge width.

Simplified Load Distribution for Vehicles with Nonstandard Axle Gauges

2000 ◽  
Vol 1696 (1) ◽  
pp. 158-170 ◽  
Author(s):  
Brian L. Goodrich ◽  
Jay A. Puckett
Keyword(s):  
Load Distribution ◽  
Live Load ◽  
Distribution Factor ◽  
Rigorous Results ◽  
Girder Bridges ◽  
Finite Strip Method ◽  
Simplified Method ◽  
Live Load Distribution Factors ◽  
Live Load Distribution ◽  
Load Distribution Factors

Several simplified methods have been developed to determine the live-load distribution factors for overweight vehicles on slab-on-girder bridges; however, these methods were developed for vehicles with standard axles. Many vehicles exist with nonstandard axle configurations, such as two-wheel axles that are wider than 6 ft (1.83 m) and four-wheel axles with wheels that are evenly or unevenly spaced. For these vehicles, a rigorous analysis is generally desired but is often deemed uneconomical. Therefore, a simplified method should be an asset to the bridge community and the trucking industry. A simplified method for determining live-load distribution factors for vehicles with nonstandard axle configurations is presented. Distribution factor formulas for moment and shear in interior and exterior girders are given. These formulas account for the transverse axle configurations that compose a vehicle. Several two- and four-wheel axle configurations are considered. The distribution factor formulas for slab-on-girder bridges presented in the AASHTO LRFD Bridge Design Specifications are incorporated into the proposed simplified method. The simplified method formulas were developed to approximate the results from a rigorous finite strip method. Comparisons are presented as verification of the accuracy of the simplified method. The simplified method results are usually conservative and correlate reasonably well with the rigorous results. In general, simplified methods worked better for interior girders than for exterior girders, and moment was better predicted than shear.

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