I design in California, for seismic loads mainly, and have done many equipment pads for large pieces of equipment.
The equipment must be anchored to the slab through mechanical means, not friction, per the code.
The seismic load is applied at the C.G. of the equipment to calculate the overturning moment. The foundation/mat slab will provide resistance to the overturning moment through the weight of the slab itself...so the anchorage or connection to the slab must be able to resist these overturning forces (these will be tension loads).
The seismic load must also have shear or lateral resistance, this is accomplished through the foundation interacting with the soil, usually friction will be enough in equipment pads such as this.
So the equipment anchors have to be designed for the tension due to the uplift due to overturning and the shear due to the lateral load.
Usually the pads are about 12" thick, sometimes with a turned down edge to get the minimum 12" below lowest adjacent grade. The soil needs to be sufficient to support the anticipated soil pressures due to dead, live and seismic loads, and is usually far less than the code minimum of 1500 psf.
The code also says that any structure must be separated so that adjacent structures do not pound against each other. But equipment pads are usually on the exterior, ground mounted and away from the structure. This is usually not a concern at all in equipment pads.
The weight of the equipment and pad are what keeps everything in place, further anchorage is not required such as soil anchors, piles, deepened foundations etc...
That's my 2 cents, although I usually charge 3 cents for all that...