The best and easiest way is employing a servo electric motor attaching to a table. This way you could simply simulate an earthquake with a very simple sinusoidal acceleration.

Just depending the power of your servo as well as its speed, you may or may not reach the peak acceleration you want. Maybe you could not even apply the frequency you want to in which in our cases will be around 1. 

In the case of modelling the footing, just forget using a plate with loading frame. It is impossible. Just use a cubic piece of very heavy metals like Lead.

If you could afford the costs, it is the best.

You could see the two way servo shaking table of Guilan University to get some idea.

For reproducing the sand liquification in the container, placed on shaking table.

Pour the sand freely in the container filled with water for 100% degree of saturation.

We used a shaking table for sieving. Check this video that we create for teaching, could be useful i guess.

http://youtu.be/oWDHjKKqVEk

Conventional shaking table use servo electric motor to generate the motion, displacement control unit consist of servo unit, vibration control unit, input equalizer, and power control unit. Soil container is attached on the shaking table, inside the soil container, cushions sheet is useful to reduce the rigidity at the both edge and bottom of shaking table. The data, such as acceleration, pore pressure or strain during shaking are stored in the data logger.

Another idea for a small shaking table, water pump can be used to generate the vibration. By using accelerometer, the wave motion could be observed.

I am using 1G shaking table test in Geotechnical Laboratory, The University of Tokyo. Please feel free to visit or ask me for further information.

http://geotle.t.u-tokyo.ac.jp/About-e.html