The higher the momentum the more likely that buildings with more than one story will get into an oscillation where the lower story and the upper stories are not moving in the same direction. What you want is a structure that will ride on top of an ocean of ground. This means that the ground will turn into a very rough lake. If you are unlucky enough to be in a hill the whole structure will slide down the hill. This means you need very simply - a houseboat.
Step1: a small reinforced concrete pad.
Step2: a three layer base of 8 x 8 pressure treated timbers:
This will give you a structure that won't roll, and will slide on anything big moving. Bolt this structure in five places to the pad, but only to hold it on up to quake of about 6-7, after that the bolts will break and let the foundation slide free
Step3: The strongest structure known to man is the cube. Build a series of 12 foot by 12 foot cubes, bolted together and reinforced with metal stripping. Built the roofing structure with isosceles triangles, bolted and metal reinforced to the cubes, which are bolted and metal reinforced to the base.
Step4: Support the outside of the structure with 1 inch plywood sheets glued and bolted to the frame, on both the inside and the outside.
When you're finished with this structure, you'll be able to let it slide down a hill, run over twenty trees on the way down and be intact at the bottom. At that point you get out your hydraulic jack, and 8 x 8's and bring it back to level.
Offered by Eric.
The idea of having a structure layingloose on top of the ground may be useful for decoupling horizontal shaking, but if vertical displacement forces are over 1g the structure will be dashed to bits as it is repeatedly tossed into the air and slammed into the ground. I have a problem with the statement that the cube is the strongest shape known to man. The failure mode of the cube is a complete flattening or "pancaking" caused when it succumbs to shear forces.
Offered by Steve