Foundation for Seismic Simulator - vibrating table 2

[geot88]

We have to do the geotechnical analysis for a seismic simulator (vibrating table) - similar to the one in the picture.
It will be founded on shale and sandstone. There is also rock underneath.
I am going for a mat foundation. Is there any recommendation anybody can give me? What method would you recommend me for the design, considering the vibration of this element?
Thank in advance!

 

[SlideRuleEra]

A mat foundation should be good. Follow the basic rules for an inertia block foundation:

1. The foundation supports only the machine.

2. The foundation has a constant thickness.

3. Mass of the foundation alone is at least 150% of the machine, including any items being tested.

4. The combined center of gravity of the foundation, the machine, and items being tested is below the top of the foundation.

5. The combined center of gravity of the machine and items being tested is centered on the foundation as closely as practical.

6. All anchor bolts are at least 12" from the foundation's perimeter.

http://www.SlideRuleEra.net

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[Mccoy]

As far as the soil analysis is concerned, The Pais & Kausel formulas on soil impedance are the easiest to apply.
The foundation is modeled as a rigid block with six degrees of freedom. Gazetas' 'Foundation vibration' article, 1991, in foundation engineering handbook, is also a seminal paper available online.

Details depend on soil model and parameters, also on the dimensionless vibrating frequency of the table.

http://www.mccoy.it

 

[Mccoy]

A spreadsheet on Pais and Kausel formulas can be found, together with a different analysis based on wolf & Deeks' cone model, in this link:

http://nuke.mccoy.it/SoilStructureInteraction/tabid/72/Default.aspx

The spread sheet Pais&Kausel can be downloaded from the link on the upper right-hand side of the webpage. It has a reference on the relevant NIST publication.

http://www.mccoy.it

 

[geot88]

Thanks all of you for your help on this thread. I've briefly studied vibration on foundations, and I needed recommendations from engineers who have more experience on this field. Thanks again for your help and tips. It's good that exists a site like this for helping others. Have a blessed day.