scholarly journals Fatigue Categorization of Obliquely Oriented Welded Attachments

2020 ◽  
Author(s):  
Robert J. Connor ◽  
Cem Korkmaz
Keyword(s):  
Longitudinal Direction ◽  
Effective Length ◽  
Fillet Welds ◽  
Bridge Design ◽  
Skewed Bridges ◽  
Primary Stress ◽  
Design Specifications ◽  
State Highway ◽  
Aashto Lrfd ◽  
The Web

In current bridge design specifications and evaluation manuals from the American Association of State Highway and Transportation Officials (AASHTO LRFD) (AASHTO, 2018), the detail category for base metal at the toe of transverse stiffener-to-flange fillet welds and transverse stiffener-to-web fillet welds to the direction of the web and hence, the primary stress) is Category C′. In skewed bridges or various other applications, there is sometimes a need to place the stiffener or a connection plate at an angle that is not at 90 degrees to the web. As the plate is rotated away from being 90 degrees to the web, the effective “length” of the stiffener in the longitudinal direction increases. However, AASHTO is currently silent on how to address the possible effects on fatigue performance for other angles in between these two extremes. This report summarizes an FEA study that was conducted in order to investigate and determine the fatigue category for welded attachments that are placed at angles other than 0 or 90 degrees for various stiffener geometries and thicknesses. Recommendations on how to incorporate the results into the AASHTO LRFD Bridge Design Specifications are included in this report.

Live-Load Response of Alabama’s High-Performance Concrete Bridge

2003 ◽  
Vol 1845 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Robert W. Barnes ◽  
J. Michael Stallings ◽  
Paul W. Porter
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Highway Bridges ◽  
Live Load ◽  
Bottom Flange ◽  
Actual Behavior ◽  
Bridge Design ◽  
Design Specifications ◽  
Special Procedure ◽  
Aashto Lrfd

Results are reported from live-load tests performed on Alabama’s high-performance concrete (HPC) showcase bridge. Load distribution factors, deflections, and stresses measured during the tests are compared with values calculated using the provisions of the AASHTO LRFD Bridge Design Specifications and AASHTO Standard Specifications for Highway Bridges. Measured dynamic amplification of load effects was approximately equal to or less than predicted by both specifications. Distribution factors from both specifications were found to be conservative. Deflections computed according to AASHTO LRFD Bridge Design Specifications suggestions matched best with the measured deflections — overestimating the maximum deflections by 20% or less. Bottom flange stresses computed with AASHTO distribution factors were significantly larger than measured values. AASHTO LRFD Bridge Design Specifications provisions suggest a special procedure for computing exterior girder distribution factors in bridges with diaphragms. When two or more lanes were loaded, this special procedure did not reflect the actual behavior of the bridge and resulted in very conservative distribution factors for exterior girders. Further research is recommended to correct this deficiency.

scholarly journals Comparative Analysis of Plate Girder Designs In The Composite Bridge Between AASHTO LRFD Bridge Design Specifications 2017 Regulation with SNI 1729: 2015

2019 ◽  
Vol 1 (1) ◽  
pp. 24-39
Author(s):  
Donald Essen ◽  
Ryza Nur Rohman
Keyword(s):  
Construction Materials ◽  
Internal Force ◽  
Construction Work ◽  
Bridge Design ◽  
Design Specifications ◽  
Construction Methods ◽  
Composite Girder ◽  
Materials Used ◽  
Plate Composite Girder ◽  
Aashto Lrfd

In the world of construction there are various methods and types of materials used to support the passage of a construction work. One of them is composite girder plate. Composite girder plate is one of the many construction methods that combine two construction materials that are physically different in nature, namely concrete with steel. This type of composite girder plate construction is commonly used for bridge construction work with a fairly large span and width. In its use, of course, it must be preceded by stages of careful planning on a standard and valid basis as well. In the following research will discuss and look for similarities and differences regarding the two types of rules in the planning of composite girder plates, namely the rules of planning composite girder plates using AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS 2017 with SNI 1729: 2015. After doing the initial stages of modeling using CSI Bridge software using the profile cross section constraints of the AASHTO provisions, the internal force obtained is Moment Force (Mu) of 3469.13 kNm and Shear Force (Vu) of 225.98 kNm. Then proceed with the analysis of calculations with the help of Microsoft Excel software namely calculating using the AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS 2017 regulations for stability requirements of strong boundary conditions on the bending requirements. Then a Nominal Moment (ØMn) value of 6420.19 kNm is obtained. Then proceed to calculate the same planning constraints, but this time using SNI 1729: 2015 regulations. Obtained Nominal Moment Value (ØMn) of 6579.88 kNm. Then it can be concluded that the two regulations produce a safe and strong planning, of course in accordance with applicable regulations namely: Moment (Mu <ØMn).

Updating the AASHTO LRFD Movable Highway Bridge Design Specifications

2021 ◽  
Author(s):  
Jeffrey Newman ◽  
Kevin Johns ◽  
Thomas Murphy ◽  
Maria Lopez ◽  
Zolan Prucz ◽  
...  
Keyword(s):  
Highway Bridge ◽  
Bridge Design ◽  
Design Specifications ◽  
Aashto Lrfd

Investigation of measured prestress losses compared with design prestress losses in AASHTO Types II, III, IV, and VI bridge girders

PCI Journal ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 32-48
Author(s):  
Ahmed Almohammedi ◽  
Cameron D. Murray ◽  
Canh N. Dang ◽  
W. Micah Hale
Keyword(s):  
Compressive Strength ◽  
American Association ◽  
Concrete Compressive Strength ◽  
Prestress Losses ◽  
Design Specifications ◽  
State Highway ◽  
Concrete Properties ◽  
Shrinkage And Creep ◽  
Bridge Girder ◽  
Aashto Lrfd

Inaccurate prediction of prestress losses leads to inaccurate predictions for camber, deflection, and concrete stresses in a bridge girder. This study aims to improve the prediction of prestress losses and provides bridge designers with insights into the differences between design and actual concrete properties. Prestress losses, compressive strength, modulus of elasticity, shrinkage, and creep were measured for several American Association of State Highway and Transportation Officials (AASHTO) Types II, III, IV, and VI girders. The investigation revealed that the measured total prestress losses at the time of deck placement were lower than the design losses calculated using the refined estimates method of the 2017 AASHTO LRFD Bridge Design Specifications. This was mainly attributed to the actual concrete compressive strength at transfer being greater than the design compressive strength. This discrepancy was as high as 73% for some girders. It was also determined that the 2017 AASHTO LRFD specifications’ refined estimates method for estimating prestress losses overestimates the total prestress losses at the time of deck placement for AASHTO Types II and III girders.

Proposed Refinements to Design Procedures for Geosynthetic Reinforced Soil (GRS) Structures in AASHTO LRFD Bridge Design Specifications

2019 ◽  
Author(s):  
Jorge G. Zornberg ◽  
Amr M. Morsy ◽  
Behdad Mofarraj Kouchaki ◽  
Barry Christopher ◽  
Dov Leshchinsky ◽  
...  
Keyword(s):  
Reinforced Soil ◽  
Bridge Design ◽  
Design Procedures ◽  
Design Specifications ◽  
Geosynthetic Reinforced Soil ◽  
Aashto Lrfd
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