Full-scale model test on load transfer mechanism for jet grouting soil-cement-pile strengthened pile

Jet grouting soil-cement-Pile strengthened Pile(JPP) is a new kind of composite pile composed of high pressure jet grouting pile and prestressed concrete core pile.In order to make a further research on load transfer mechanism of JPP under vertical loads,the full-scale model test of JPP,cast-in-place pile and jet grouting soil-cement pile have been done in the test room which is developed for this test.With the pre-arranged instrument in JPP,the axial stress,dip resistance and settlement of pile have been measured;and distribution of axial force and friction resistance are also analyzed.Experimental results show that: bearing capacity of JPP is thirty percent higher than that of cast-in-place pile which has the same length and diameter with JPP.The deformation of JPP is controlled by core pile;axial force distribution of PHC is different with soil-cement;and their axial force ratio in same section is their elastic modulus ratio.Distribution of inner and outer friction resistance is similar;and the inner friction is about 1.62 times of the outer one;it is about the ratio of JPP diameter and PHC diameter.Furthermore,the relation between friction resistance and relative displacement is similarly hyperbolic;and the relation between dip resistance and displacement is also hyperbolic.