Dynamic Compaction in Friable Loess

An experimental investigation was conducted to determine the change in engineering properties of a collapsible loess in Bulgaria resulting from dynamic compaction. The results of in situ tests conducted before and after compaction are described. A 13,605-kg (15-ton) circular concrete tamper was dropped from a height varying between 5 and 10 m (16 and 33 ft) to produce impact. Density measurements taken before and after compaction and in situ tests using dynamic cone and dilatometer, indicate that the effective depth influenced by the compaction was about 4 m (13 ft). The results suggest that the potential for collapse has been significantly reduced by dynamic compaction.