COMPARED AND ANALYSIS CALCULATION METHOD OF CFG PILE COMPOSITE FOUNDATION ON SETTLEMENT ON DEEP AND SOFT SOIL

This paper combine Liyao test section of Beijing-Shanghai high-speed rail, compared and analyzed deep and soft soil CFG pile composite foundation various additional stress and settlement calculation methods in reinforcement zone and substratum. The results show:(1) Boussinesq solution can accurately calculate additional stress of reinforcement zone in composite foundation, Mindlin-Geddes solution can accurately calculate additional stress of the substratum in composite foundation.(2) Area weighted method can effectively calculate additional settlement of reinforcement zone in composite foundation.(3) the additional stress of substratum in composite foundation calculated by linear superposition that the method can effectively consider settlement of substratum in composite foundation under pile group.(4) There is very similar for the results between area weighted method and elasticity caculated method, and much larger than the pile-soil modulus ratio method.(5) the settlement underlying layer of composite foundation would increase with the increase of the piles number in the same replacement rate.