Computational analysis and experimental study on a new connection between segments of square uplift piles

The precast prestressed concrete pile as the uplift pile has a series of merits, such as good crack resistance, quick construction and economy etc. It has broad application prospects. However, there are still some technical issues which need to be solved, for instance, joint quality. The prestressed concrete hollow square uplift pile with internal thread (NKBZ pile in short) is a newly developed uplift pile, which uses the way of internal buckle mechanical connection between pile segments. Combined with the specification formula, the methods for tension capacity of prestressed concrete hollow square uplift pile with internal thread are analyzed and summarized. A series of axial tensile tests are carried out to verify the tensile property of the new connection. The test results indicate that the upset head and end plate are weak parts due to stress concentration. It may provide references for its further development.