Performance evaluation of high energy dynamic compaction on soil-rock mixture geomaterials based on field test

Dynamic compaction (DC) is an efficient ground treatment technique that has been widely used for different soil types, however, the investigation on performance of high energy level DC for soil-rock mixture backfills is rare so far. This study presents a field investigation of the effectiveness of DC with a maximum energy level of 10,000-kN·m on soil-rock mixtures in southwestern China. Field tests, including surface wave test (SWT), super heavy dynamic penetration test (SH-DPT), and plate load test (PLT) were conducted to evaluate the effectiveness of DC under different conditions. The effectiveness and improvement depth were discussed based on SWT and SH-DPT. The results showed that the ground bearing capacity increased significantly after DC treatment both under non-soaking and soaking conditions. For the testing site with a fill thickness of 10 m, the allowable ground bearing capacity exceeded 300 kPa after DC treatment. The deformation modulus was measured to be 15 MPa. However, the impact of DC on the site with a fill thickness of 30 m is limited, and additional ground improvement measures are required for design.