Compaction of Hydraulically Placed Fills

On the basis of the literature and experience with the placement and compaction of numerous hydraulic fills, it appears that a relative density of 50 to 60% can be obtained with no compaction for well-controlled hydraulic fills containing less than 10% fines. Some other requirements for a well-controlled hydraulic fill are: (1) the water table must be well below the surface of the fill so that there is downward drainage at all times; (2) material must not be bulldozed into low areas without subsequent sluicing, otherwise low densities will result; (3) a uniform flow must be maintained over the fill surface by use of bulldozers and shear boards to direct the flow of water; and (4) deposition into pools of water must be prevented in order to eliminate the accumulation of fines and resulting low densities. If hydraulic fills require relative densities greater than 50 to 60%, then compaction rolling above the water table is required with (track) tractor or rubber-tired rolling equipment or with a steel drum vibrating roller.