Theory Analysis And Test Study On The Compaction Effect Of Compaction Piles

With the improvement of the west—China development, capital construction project in loess areas has been increased greatly in recent years. The compaction pile is one of the effective soil improvement method in loess areas, especially in collapsible loess ones. So it is very important to research on the soil compaction effect of compaction piles, not only in theory, but also in project practice.According to the discussion above, this paper has study the compaction effect of compaction piles directed toward loess area. First, based on the tradition theory of cavity expansion, the paper study the change of soil stress one the use of the Modified Cambridge model and the elastic-plasticity theory, establish the theoretical formulas of soil stress and displacement between piles under symmetric condition and compare with the formulas based on the Mohr-Coulomb criteria. Second, according to the parameters based on the common tri-axial compression and lateral confinement compression test on the undisturbed soil sample, this paper calculate the soil stress between piles and dry density on the use of FORTRAN program, thus make some important conclusions. Finally, this paper compare the calculated dry density with the results tested on the soil around piles, testify the authenticity of the suggested formula.