History and Basis of AASHTO Loadings

[X-Wing]

Anyone know or has a link/reference, preferably dissertations or official archives of codes about the History of AASHTO Loadings?
Where they came from, and how are they derived, how are they studied to be the standard loadings for our AASHTO Codes?

For example, from MS-18, how did they changed it to HL-93 equivalent?

My take is maybe they are based on statistical data, bridge inventories, etc, but I need their study, if they have copy.

This is for my study on overloadings in bridges.

Thanks!

 

[bridgebuster]

You're mixing apples and oranges in terms of truck loading. HL-93 is the live load for the LRFD Specification. It was developed through a statistical study of actual trucks. Google can lead you to plenty of discussion on HL-93.

MS-18 is the live load that was used with the Standard Specifications. Find some old books on bridge engineering, early 20th C., @ Google Books. You'll find how the HS truck evolved.

 

[X-Wing]

Thanks Sir bridgebuster for the reply!

Do you have any files/links/website in particular for this matter? I have been researching about this but still cant have any related topic. Or keywords on the search. Thanks!

 

[bridgebuster]

Try these; the third link has some historical perspective.

http://onlinepubs.trb.org/onlinepubs/archive/notesdocs/20-07(186)_fr.pdf

http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_700.pdf

http://mceer.buffalo.edu/education/...ulicki Part 1 Bridge Design Specs history.pdf

 

[X-Wing]

thanks sir bridgebuster for the links!! I'll read these articles, anyone else that have reference please it will be greatly appreciate, thanks!!

 

[bridgebuster]

you're welcome

 

[GWWilliam]

The following 2 paper give a nice summary of the AASHTO Truck history and an update about the suggested live load trucks.

Enhancement of bridge live loads based on West Virginia weigh-in-motion data

Journal Bridge Structures - Assessment, Design & Construction
Publisher IOS Press
ISSN 1573-2487 (Print)
1744-8999 (Online)
Subject Civil and Structural Engineering
Issue Volume 4, Number 3-4 / 2008
Pages 121-133

http://iospress.metapress.com/content/p18n45827826687v/?p=e5109a2e8f2449e09dca2fcbdde71e9e&o=0

Collecting and using Weigh-in-Motion data in LRFD bridge design
Full TextPDF (127.2 KB)Full TextHTML
DOI 10.1080/15732480903143045
Journal Bridge Structures - Assessment, Design & Construction
Issue Volume 5, Number 4 / 2009
Authors
Bala Sivakumar and Michel Ghosn

 

[X-Wing]

Thanks to the reply sirs!

To keep this thread alive, anyone know the reason on why lane load now are added to truck loads?

 

[bridgebuster]

The addition of the lane load is to more accurately portray the loading effects of HS20 traffic on a bridge structure to account for trucks that have been getting larger and heavier since HS20 was introduced in 1944. It also ensures greater durability of the structures by making them more robust.