Analytical solution to settlement of cast-in-situ thin-wall concrete pipe pile composite foundation

Abstract

The cast-in-situ thin-wall concrete pipe pile (PCC pile) is increasingly employed as a soft soil improvement technique in China. The formed composite foundation by using PCC pile renders a competitive advantage compared to conventional comparable soft soil treatment techniques. To calculate the settlement of PCC composite foundation helps better design a soil improvement scenario and understand the mechanism of PCC composite foundation. In this study, an elastic analytical solution to deformation modulus of PCC composite foundation was developed based upon the pile-soil-cushion interaction system and model analyses. Using the calculated modulus, formula presenting pile-soil stress ratio and composite foundation settlement were derived. A case study was conducted to verify the calculations. It is indicated that calculated settlements are in consistency with fielding monitoring data.