Equal energy,equal deformation tamping and expansion gangue pile is a new strengthening method,which not only has the effect of tamping and expansion,but also strengthens complex earth-fill.

To treat the deep-thick backfill foundation with ram-compaction gravel piles for a sewage farm,four typical sections within the construction site were selected for the evaluation testing .

According the project practice, the method of adopting the local natural grit as the meterials of the enlarged compaction pile by tamping is put forward, the process and the main construction points of the method is introduced, the quality requirements is emphasized.

The composite foundation formed by CFG pile and drilling ram expanded pile (DRE pile) which used widely in Beijing area are applied to a project, using CFG pile to minimize the building settlement and DRE pile to improve shallow soil bearing capacity respectively.