Study On Settlement Computation Method Of CFG-pile Composite Foundation

Composite foundation is generally used to improve the bearing capacity and (or) decrease the foundation settlement. Therefore, the bearing capacity and settlement theory are very important theory in composite foundation, and they are also the basis for the design. However, the current composite foundation settlement theory lags far behind the engineering practice. To CFG pile composite foundation for the study, this paper discusses the composite foundation settlement computation problems via the interaction of piles, pile-soil, and cushion.In order to calculate CFG composite foundation settlement, this paper puts forward the following ideas: through the mechanical properties analysis of soil surrounding piles and pile-soil surface, and the CFG composite foundation deformation characteristics, pile-soil stress ratio should be analyzed under three phases. Elastic, elastic-plastic, and all plastic soil express that the composite foundation works under little, normal and ultimate load. Based on this, a simplified mechanical model of soil-pile system is established, which in turn may consider pile, soil, cushion deformation differential equations. Theoretical solutions are deduced. After obtaining pile-soil load share, assuming distribution behavior of skin friction, the composite foundation settlement by the Mindlin displacement solutions are calculated. Through comparing to the measured results and theoretical calculation, the results show that the method in this paper is effective and rationality.