Without knowing the loads, etc., of course drilled piers and or ground anchors are an effective method of countering uplift considerations. In the former they are good, too for compression loading; the latter need to be included in a suitably sized foundation for the compression loading. Another way to counter the uplift is to provide a large footing under each leg to a size so that the weight of the soil/rock backfill above will be more than the uplift loads. That is what the designer on my current job did - even with rock near the surface, rubble mortared counterweights were used rather than anchors - of course, the choices depend on location, cost of labour and materials vs machine costs, etc. . .