pavement - Single Wheel Loading to Double Wheel Loading

[qaztor]

A runway has a pavement strenght of 23,600 lbs(single wheel loading). This might be very simple (or not?) but I haven't been able to find information on how to convert or co-relate single wheel loading with Dual wheel loading. In other words which is the Dual wheel loading of such pavement? how did you get it?
Thanks.

 

[ishvaaag]

One may build correlations based on the maximum stresses caused but either kind of loads.

The only thing in my hands -other than how to calculate things- dealing with single and paired wheel effects is a downloadable pdf article

TRUCK TIRES, SUSPENSION DESIGN AND ROAD DAMAGE
DJ Cole* and D Cebon*

 

[Focht3]

What are you designing - a highway, airport taxiway/apron, or runway? And have you ever designed one before?



Please see FAQ731-376 by [blue]VPL[/blue] for tips on how to make the best use of Eng-Tips Fora.

 

[qaztor]

ishvaaag - thanks. It does not look like something related to runways but I would like to read it. could you please send me a copy of that document? qaztor@yahoo.com

Focht3 - As it says it is a RUNWAY. It is an existing runway with the pavement strenght capacity described. Since the original pavement section is unknown (no bores are available either) that is why I asked. And yes I have experience designing runways, taxiways, Aircraft parking Aprons, highways, and parking lots. Does it matter?

After some calculations I can also share with you that the critical aircraft for this Airport (B-II), will impose a dual wheel load of 30875 lbs. A regression with values for SWL and DWL from several large and small airports in the area (Arkansas, Oklahoma, Texas, LA) gives us a mean factor of 1.55. This represents a Dual Wheel Loading of about 36000 lbs (23600 x 1.55) for the runway in question. Any comments on this probabilistic aproach. thanks

 

[VAD]

Hello gaztor:

I am not sure that you are providing the necessary information for us to determine what you are looking for. Certain things such as spacing of dual wheels, gear configuration etc are generally part of the equation. However, from your calculations one can derive that the dual spacing is 30.83 inches. This gives a factor of 1.308 using the US Navy Procedure for flexible Pavements. On the other hand you may have an approach that works.

Equivalent Single wheel load determined fom dual loads etc is one of the first things that one gets taught when looking at loadings whether related to highway or runway pavements. The text that is popularly used is Principles of Pavement design by Yoder and Witczak. You should find your answer by thumbing through this book. I am sure you have a copy.

Finally, I think that Focht 3 comments were as a result of the way the question was asked. I also had that impression as well. However, coming in at this point after your explanation I can relate somewhat to what you are looking for.