The second is that,the method of compacting several layers wad successfully used to prevent spontaneous combustion of coa gangue heap.

Combining the engineering practice,the author recommends that with this method,firstly the earthfilling pretreatment should be given to the backfill consolidation in layers,then dynamic consolidation adopted,twice the result with half the effort can be obtained.

In order to study thick compaction and enhance its quality and efficiency,the theory of impactlike compaction is analyzed and an impact-like prototype is made by using proprietary technology.