Compaction Control Bermuda Sports Centre

摘要

The new national sports centre in Bermuda encompasses numerous facilities, including playing fields, which are located in an area previously filled with up to 6 m of loose granular materials. It was decided to re-compact the upper 3 to 4 m of the fill in order to provide a serviceable playing surface. A geotechnical investigation, which included both test pits and sampled boreholes, found that the fill was composed of aeolinite bedrock, which is a weakly, cemented friable limestone. This was found to overlie undisturbed bedrock. The limestone was composed of about 60 percent solid particles of shell fragments, ooliths and pellets and about 10 percent calcite cement. The porosity was about 30 percent. Normal compaction testing was difficult since the only nuclear gauge on the island had not been calibrated for several years and the Proctor values for the excavated limestone gave results lower than those measured in situ. It was decided to determine the maximum density of the fill using trial test strips. The test strips were found to be the most suitable method of evaluating the compaction. It was found that the aeolinite could be compacted in 300 mm lifts with heavy vibratory compactors.