The technical process of tamping macadam compaction pier is as follows: firstly form pores artificially,then replace the soft soil with the scree and tamp to close-grained scree pier by layered power.

Problems existing in improvement of loess ground by method of dentification by tamping and expansion are analyzed herein.

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.