scholarly journals Validation of the AASHTO LRFD Live Load Distribution Provisions for Integral Abutment Bridges

2020 ◽  
Author(s):  
Sami W Tabsh ◽  
Shehab El Din Mourad
Keyword(s):  
Load Distribution ◽  
Live Load ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Abutment Bridges ◽  
Live Load Distribution ◽  
Aashto Lrfd

scholarly journals Live-Load Testing Application Using a Wireless Sensor System and Finite-Element Model Analysis of an Integral Abutment Concrete Girder Bridge

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Robert W. Fausett ◽  
Paul J. Barr ◽  
Marvin W. Halling
Keyword(s):  
Load Distribution ◽  
Element Model ◽  
Live Load ◽  
Load Testing ◽  
Integral Abutment ◽  
Simply Supported ◽  
Live Load Testing ◽  
Girder Bridge ◽  
Live Load Distribution ◽  
Aashto Lrfd

As part of an investigation on the performance of integral abutment bridges, a single-span, integral abutment, prestressed concrete girder bridge near Perry, Utah was instrumented for live-load testing. The live-load test included driving trucks at 2.24 m/s (5 mph) along predetermined load paths and measuring the corresponding strain and deflection. The measured data was used to validate a finite-element model (FEM) of the bridge. The model showed that the integral abutments were behaving as 94% of a fixed-fixed support. Live-load distribution factors were obtained using this validated model and compared to those calculated in accordance to recommended procedures provided in the AASHTO LRFD Bridge Design Specifications (2010). The results indicated that if the bridge was considered simply supported, the AASHTO LRFD Specification distribution factors were conservative (in comparison to the FEM results). These conservative distribution factors, along with the initial simply supported design assumption resulted in a very conservative bridge design. In addition, a parametric study was conducted by modifying various bridge properties of the validated bridge model, one at a time, in order to investigate the influence that individual changes in span length, deck thickness, edge distance, skew, and fixity had on live-load distribution. The results showed that the bridge properties with the largest influence on bridge live-load distribution were fixity, skew, and changes in edge distance.

scholarly journals Safety Identifying of Integral Abutment Bridges under Seismic and Thermal Loads

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Narges Easazadeh Far ◽  
Majid Barghian
Keyword(s):  
Maintenance Cost ◽  
Seismic Load ◽  
Seismic Loads ◽  
Integral Abutment ◽  
Bridge Design ◽  
Safety Level ◽  
Integral Abutment Bridges ◽  
Load Combination ◽  
Abutment Bridges ◽  
Aashto Lrfd

Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an “always on” load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs—designed by AASHTO LRFD bridge design code—under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code’s load combination should be changed.

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