“Conventional wisdom” amongst users of cutting-edge electron microscopes and other sensitive research instruments is that their instrument will perform better if supported on a “thick” concrete slab-on-ground. Typically, their choice of a slab thickness is based on what worked well for someone else, without any thought given to an analytical justification. The paper presents the results of a study of the dynamic stiffness properties of a collection of slabs-on-ground. The primary variables governing slab performance were found to be its thickness, a dynamic subgrade modulus, and a damping term—leading to a representative thickness-dependent model of slab behavior.
Amick, H., “Dynamic Stiffness and Subgrade Modulus of a Slab-on-Ground,” manuscript submitted to Structural Journal of the American Concrete Institute, in peer review (2011)