Application Of Fender Piles In The CFG Pile Composite Foundation In Strongly Weathered Soft Rock

Analysis of the performance of CFG pile composite foundation found that a plastic deformation zone surrounding the CFG pile composite foundation with an area of about one time piles' distance was formed, and it is the main cause of instability of the whole composite foundation. Comparative analysis of characteristics as stress change, foundation settlement of the composite foundation before and after adding a row of fender piles in the plastic deformation zone, found that foundation performance got obvious change after pile enforcement. In the same conditions, the foundation settlement reduced significantly and the stability improved obviously. Fender pile refers to the piles located outside a foundation and its sphere of influence area with the function of reducing foundation settlement and improving the stability of the foundation. Simulation analysis of the CFG (Cement Fly - ash Gravel) pile composite foundation found that a plastic deformation zone was formed outside pile lateral about one times pile distance area of the CFG pile composite foundation, and it is the main cause of the instability of the whole composite foundation (1). So, setting fender pile in the CFG pile composite foundation laterally to prevent this kind of plastic deformation zone can increase the CFG pile composite foundation stability and reduce ground settlement.