Experimental Study on Inner Interface Mechanical Properties of the ESDCM Pile with Steel Core

The mechanical property of the pile-core–cement-soil interface is a crucial factor affecting shaft capacity expanded stiffened deep-cement-mixing (ESDCM) pile. research on characteristics steel-pipe–cement-soil very limited, and conventional concrete–cement-soil results cannot provide direct guidance for engineering application combination Hence, in this study, we employed model pile with combination. By using confining pressure transfer test an inner shear test, influence deformation were investigated. demonstrated that lateral has almost no effect due to encapsulation soil-cement column. experienced four stages: steel pipe small deformation, which extra stage compared common form; whole compression; brittle failure; shear-slip stage. peak stress at 194 kPa, corresponding core top displacement bottom are 5.9 mm 5.4 mm, respectively. bond coefficient only 0.052, indicating even smooth can work closely cement-soil low bonding coefficient. Further optimization structure be essential means improve properties When upper load transferred downward, it spreads around through cement-soil, as increases, finally deep part accounts relatively amount, about 7%. This promotes understanding ESDCM piles guides practical engineering.