THE INFLUENCE OF SOIL-MOISTURE AND COMPACTION ON SPILLWAY EROSION

Submerged jet tests were conducted on a soil material compacted by dynamic and static load methods over a range of dry unit weights and moisture contents. The compacted soil samples were pre-wet prior to testing. An index parameter was used to compare changes in the erosion resistance of the soil at different compacted dry unit weights and compacted moisture contents. Moisture content at the time of compaction had a significant influence on soil erosion resistance. Additionally, at a constant moisture content, the erosion resistance increased as the dry unit weight increased. These results, along with results of two compacted spillway channel tests on the same soil, suggest that proper compaction should be considered in the repair of earthen auxiliary spillways.