Experimental study on bearing characteristic of super-long precast pipe pile in sandy soil area

Few formulas can be used for calculating vertical bearing capacity of the precast concrete pipe pile at present,and none of them are relatively accurate.According to the static load test of single piles in a sandy soil field in Yangzhou,the bearing characteristic of super-long concrete precast pipe pile was analyzed.At the same time,based on the test data,we compared and analyzed the reliability of code formula and document formula used for calculating the bearing capacity of super-long precast concrete pipe pile in sandy soil foundation.Results showed that eight test piles had punch-through failure and two test piles had slowly-changed failure under maxi-mum test load.The reliability of determination of bearing capacity of the super-long precast pipe pile by standard method is greater than that obtained by document method in calculation.The ratio of tip resistance of all test piles calculated by three kinds of formulas were between 16. 15%~21. 1 1%,indicating that the super-long con-crete pile was friction pile in that area.