Bridge Abutment Footing
Bridge Abutment Footing
(OP)
I have point load maximum of 21.0 k at each wheel (42 k axle load) Do I have to design the footing assuming all the load acts directly on the footing or I can assume the load spreads along more of the footing area through the medium of the abutment. I was concerned about punching shear at the footing.
In other words, should I design the footing assuming all the 21.0 k acts at a single point on the footing?
In other words, should I design the footing assuming all the 21.0 k acts at a single point on the footing?






RE: Bridge Abutment Footing
But the answer of how to distribute the load to the foundation gets a little murky from there. Some points to consider are:
1. Does the endbent/abutment have a concrete diaphragm encasing the longitudinal girders? If yes, the distribution may follow more along the lines of a 2:1 through the diaphragm, though AASHTO does have distribution formulas.
2. If there is no diaphragm encasing the girders, then the wheel load(s) is positioned on or between the girders where it is transferred to the supporting girders by simple beam distribution. The reactions of the girders now become point loads acting on the footing or abutment beam.
I hope this helps.
Regards,
![[pipe] pipe](https://www.tipmaster.com/images/pipe.gif)
Qshake
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
RE: Bridge Abutment Footing
Am I right in that assumption?
Thanks
RE: Bridge Abutment Footing
If there is a shearing mechanism between the girders, a shear key or post-tensioning bar (assuming you have adjacent box beams or deck beams for your bridge) you could potentially get distribution across the joint. You have to check AASHTO.
Regards,
![[pipe] pipe](https://www.tipmaster.com/images/pipe.gif)
Qshake
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
RE: Bridge Abutment Footing
I do have shearing mechanisms between the adjacent box beams.
However, to be conservative, I will assume the load is 5.25k/ft across the whole footing.
RE: Bridge Abutment Footing