PAVEMENT STRUCTURAL NUMBER 2

[mikewi]

DOES ANYONE KNOW THE FORMULA SUITABLE FOR SPREADSHEET USE FOR CALCULATING A PAVEMENT SN (STRUCTURAL NUMBER) KNOWING THE TF (TRAFFIC FACTOR) AND CBR/IBR (CALIFORNIA/ILLINOIS BEARING RATIO?

 

[dik]

You might want to repost this in Engineering spreadsheet forum.

Dik

 

[LHA]

You'll need several more factors. There is an "equation" for SN once you have all factors, but it is a whopper. I wouldn't try to write a spreadsheet for it. There is a nomograph for SN here:

Flexible Pavement Design Nomograph from American Association of State Highway and Transportation Officials, (1993). “AASHTO Guide for Design of Pavement Structures”.

A good, brief discussion of technique is here:

http://www.tenaxus.com/roads/designinformation/GRID-DE6.pdf

Engineering is the practice of the art of science - Steve

 

[Scott367]

I got some free software from the pro concrete people

 

[Ron]

As LHA says, it's a whopper....I did a spreadsheet for it, but it essentially required that I break down the nomograph equation into three parts so that Excel could take it.

Use the AASHTO equation and keep it general with flexible input. That way you can design the pavement section based on a variety of input factors, not just CBR or other stability criteria.