Jet grouting soil-cement-pile strengthened pile (JPP pile) is a new kind of composite pile composed of high pressure jet grouting pile and prestressed core pile. JPP pile has different combination forms depending on soil conditions as well as the bearing capacity requirements. Based on the simplified calculation method presented

the main factors of JPP pile bearing mechanism

different combinations

different soil-cement thicknesses

different elastic moduli of soil-cement

and different stiffness coefficient ratios

are analyzed comparably. The axial force of core pile

soil-cement axial force

first interface resistance and second interface resistance

are discussed respectively. The research results show that: (1) The sub-combination JPP pile has better carrying effect and should be adopted in actual construction. (2) Increasing soil-cement thickness can effectively improve the bearing capacity of JPP pile

but should not be too thick

and should not be greater than the radius of the core pile. (3) Soil-cement elastic modulus has small effect on axial bearing properties of JPP

but should meet structural requirements. (4) The stiffness coefficients should not be too small and not less than 100

so as to achieve deformation coordination for soil-cement and core pile

and improve bearing capacity and reduce settlement of JPP pile.