IN-SITU TEST AND THREE-DIMENSIONAL FEM ANALYSIS OF DYNAMIC COMPACTION EFFECT OF THICK FILL EMBANKMENT

One Thick fill embankment was composed of broken rocks in Henan province. It was taken as an engineering example in this paper. A construction technology of dynamic compaction with energy of 1000 kNm and loose layer of 1.5m depth was put forward. In-situ tests were done at some segments. The loose layers turn dense after having been compacted and the horizontal efficient compaction range was 4m and was displayed from the ground radar wave shape. Rayleigh waves change little in the depth and the averaged value is 310ms-1. The segments have middle density judged with the heavy dynamic penetration tests results. The solid volume ratios tested with water replacement method were all above 83%. So, an important conclusion was obtained that the segments after having been dynamically compacted can have better compaction effect. The FEM software of ABAQUS was adopted. The dynamic compaction was simulated by taking the pounder as a rigid body and assigning the pounder with a vertical initial velocity. The efficient compaction range can be judged by the settlement of 20mm according to the conclusion from ground radar. Finally, dynamic compaction on the embankment with a buried culvert was simulated, which reveals that the depth of embankment upper culvert must be larger than 8 m for safe dynamic compaction.