Field Test Evaluation of High Energy Dynamic Compaction on Coarse grained Gravel Fills

Abstract:

A field test study was carried out by using high energy dynamic compaction (HEDC) with 15 000 kN· m energy on coarse grained gravel fill materials. In the course of tamping, the settlement of the crater per drop was monitored for all impact points at the first three passes, and the ground surface deformations around three impact points were also measured. It can be seen that the average crater depths reach 4.38 m, 3.71 m and 1.93 m for the first, second and third passes, respectively. Also, no ground heave was observed during construction. After HEDC, the spectral analysis of surface wave (SASW) test was undertaken before and after HEDC in order to determine the depth of improvement. The SASW measurements indicated the depth of improvement following HEDC was not less than 16.5 m and there were no obvious weak layer. Based on three plate load tests, the allowable bearing capacities of the site after HEDC also met the design requirements. Finally, the n values in Menard formula was determined to calculate the improvement depth for HEDC of coarse grained gravels. This provides the references for the design, construction, and detection of HEDC at similar sites.