Plastic Behavior for Compaction Pile with Hole Expanded by Blasting or Tamping Techniques

This paper presents a new method to predict the pla stic radius of compaction pile with hole expanded by blasting or tamping tech niques. The new formulae are obtained based on Yu's unified strength theory. The strength difference in tension and compression and intermediate principal stress effec t on the material strength are considered, and, hence, the obtained formulae can b e used for a wide range of materials. The plastic zone of soil during hole-for ming by blasting and tamping techniques can be predicted based on the derived fo rmulae in this study. The effects of the blasting and tamping process on the adjacent piles can be reasonably assessed, and the weight of hammer and tamping times can then be determined. Previous results obtained based on Tresca, Mises, and Mohr-c oulomb criterion are all special cases of the results derived in this paper.