According to the control settlement and sparse piles theory

the applicability of prestressed concrete（PTC） piles with cap in the profundity soft soil ground treatment of a highway has been discussed.The spot tests of single pile with cap composite foundation and single pile without cap composite foundation have been done in order to master its working mechanism and investigate the mechanical behavior of load-bearing capacity

load transfer

earth pressure beside pile

the skin friction of pile

sharing of load and pile-soil stress ratio of PTC pile with cap composite foundation.The test results have been analyzed and researched deeply;and some useful conclusions are drawn

by the experiment

which can provide reasonable test base for us to study the theory of PTC pile with cap composite foundation and may be a guide to design control settlement and sparse piles composite foundation.