Fire Truck Surcharge on Cantilevered Retaining Walls
Fire Truck Surcharge on Cantilevered Retaining Walls
(OP)
We are designing several tall cantilevered retaining walls that range from 8’-0” to 16’-0” of retained soil. The walls are subject to a traffic surcharge load as there is a parking lot within several feet of the walls. In the past we used a surcharge of 250 psf and believed this adequately accounted for any traffic loads. However, we are concerned if a large fire truck should park next to the wall and if the 250 psf surcharge is adequate to account for this load (especially if the truck has outriggers).
Is there a uniform surcharge load that can be used to properly account for the operating weight and reactions from a fire truck? This may be pretty straight forward to those of you who do DOT work on a regular basis, but our firm designs buildings and we usually do not design walls subject to these kind of loads. Thank you in advance for your expertise.
Is there a uniform surcharge load that can be used to properly account for the operating weight and reactions from a fire truck? This may be pretty straight forward to those of you who do DOT work on a regular basis, but our firm designs buildings and we usually do not design walls subject to these kind of loads. Thank you in advance for your expertise.





RE: Fire Truck Surcharge on Cantilevered Retaining Walls
RE: Fire Truck Surcharge on Cantilevered Retaining Walls
RE: Fire Truck Surcharge on Cantilevered Retaining Walls
You could also try NAVFAC DM 7.2 (google that). It stands for Naval Facilities Design Manual 7.2. I think that one has a pretty straight forward chart with equations. It is a free download, an oldie but a goodie.
RE: Fire Truck Surcharge on Cantilevered Retaining Walls
CalTrans Bridge Design Specifications - Chapter 5 - Retaining Walls
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Fire Truck Surcharge on Cantilevered Retaining Walls
There is a case to be made that the firetruck situation is an extreme event as well and the load would not be factored (or lower FS used). Of course, the fire truck could be there putting out a fire due to an earthquake and additional tremors are occurring as the truck arrives. Many walls have loaded concrete trucks right behind them as the pavement goes down and they are designed for 250 psf. It is easy to get carried away with these What If scenarios in my opinion but sometimes major problems occur when an excessive loading condition like a large crane picks from behind a wall.
RE: Fire Truck Surcharge on Cantilevered Retaining Walls
http://www.yakpol.net/surcharge_down.html
Yakpol