Abstract: Golf course specifications include vague references to compaction. Some promote bulldozer tracking, and others require rolling and compaction testing. What’s the best compaction method?
I recently read specifications for a sportsfield renovation. The project involves subgrade preparation and spreading loam over an acre and a half. The design engineer required that after grading the field, the contractor will roll the surface four times with a heavy roller. The engineer doesn’t understand that if properly bulldozer tracked, the field will settle evenly
I see this philosophy in golf course construction. Some worry that fairway and rough areas will settle unevenly if they are not compacted before seeding. One owner wanted me to run a big Cat roller down his newly finished fairway.
I tell my shapers to track in all flat work. When working a fill area, spread about a foot of material, and then run the dozer back and forth with the blade up. This will form compacted lifts, with increased strength caused by intensive tracking. These lifts will settle evenly.
If the fill ends in a 3:1 slope or more, this detail works well. If it ends in a sharper detail, like a 2:1 slope, you may need to install geogrids, or HDPE webbing, on the exposed slope to strengthen the edge.
Feature work requires more compaction. You must intensively compact bunker and mounding faces. I’ve seen poorly compacted features soften over time, forming the dreaded “melted ice cream” look whereby sharp features at seeding turn to mush after a few years. Feature shapers using excavators must install fill in six inch lifts and bucket-compact each lift. This will maintain feature strength without settling.
Tee and green mix compaction starts another argument. Most supers are paranoid of compaction. If you drive a roller on a newly filled green core they will have a fit. I insist on track compaction of seedbed mix, and this provides enough insurance against uneven settlement.