Soil spring stiffness

[tuanphamanh]

Hi

I’m a structural engineer. I model an integral abutment bridge in ADINA software. For the interaction between the backfill and the abutment, I use a soil spring model. The stiffness of the spring is equal to lateral stiffness of backfill (granular soil). Does any body know how to calculate the spring stiffness, and how does it change with temperature varying from -25 C to 30 C.
Or please recommend me some papers and books about that problem.

Thank

 

[Qshake]

Your best bet is to search the web for information. However, I recommend that you search reptuable sources. The problem is not new and has been around for some time. At least since the early 80s if not before then. Some references that you will find useful

Wilson's paper on Abutment stiffness of skewed bridges,

FHWA's Seismic Design of Highway Bridges 1987,

Papers by Gazetas will help on soil springs in general and

FHWA's geotechnical seismic design of foundations by Earthtech.

The latter has an extensive treatment for foundations on piling and spread footings.

The 1987 FHWA reference has a nice section on the practical non-linear treatment of the soil springs and when the soil yields as well as closing the gap at the abutment-superstructure.

Good Luck.

Regards,
Qshake

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[BigH]

Also might want to check out Dr. Horvath at Manhattan University. Use of a "spongy" geofoam is a possibility to reduce the effects of the thermal ins and outs.