抄録
A simplified method is proposed to estimate the improvement effect achieved with various compaction piles for sandy soils containing fines. It is indicated that the main factors affecting the compaction effect are : 1) initial soil conditions such as initial density and fines content, 2) effective overburden pressure, 3) replacement ratio (defined as the ratio of the volume replaced by the pile to the unit volume of in situ soil), 4) ground surface swelling, and 5) nonuniform densification. Based on analysis of extensive field data and previous studies, several empirical relationships incorporating the factors stated above were established. With this method, the improvement effect can be estimated by comparing the normalized SPT N-values before and after improvement. The estimated results have been compared favorably with those obtained from field investigations. It was confirmed that the suggested method can be adopted in the actual design of various compaction piles.
