Jet grouting soil-cement-pile strengthened pile（JPP） is a new kind of composite pile

and has the advantages of high bearing capacity and low cost.Using the software FLAC3D

the paper mainly focuses on the vertical bearing behavior of JPP pile group.Some influential factors

such as pile number

pile spacing

pile length

combination forms and elastic modulus of soil-cement

are introduced and their effects on vertical bearing behavior are analyzed respectively.Simulation results show that: the bearing capacity increases with pile number

but the bearing capacity of 16-pile group is almost the same as that of 25-pile group

so we can conclude that the bearing capacity of 16-pile group may represent that of over 16-pile group;the bearing capacity decreases with pile spacing increasing

a better pile spacing is about three times of JPP diameter or four times of core pile diameter;the bearing capacity increases with pile length;JPP with segment combination may obtain a higher bearing capacity and is more suitable in practical engineering;the increase of elastic modulus of soilcement does not affect the vertical settlement

but decreases axial force of core pile.