How are heavy-duty net post sleeves anchored into concrete footings?

Heavy 3-inch steel net posts exert continuous horizontal tension of several hundred pounds on their anchors. If posts are cored directly into a thin 4-inch surface slab, freeze-thaw cycles and cable tightening will crack the concrete. Professional court construction requires boring separate subterranean bell footings measuring 18 inches in diameter and 36 inches deep (extending below the regional frost line). Heavy galvanized steel sleeves are leveled in place and filled with high-early-strength 4,000 psi concrete. Removable post caps allow posts to be retracted during multi-purpose gym conversions.