Abstract: This paper presents the PHC pipe pile static axial load tests in the argillaceous siltstone in Changsha area. When the tip of the PHC pipe pile in the argillaceous siltstone, the Q-S curve is steep, and has obvious failure points. The axial capacity type belongs to end-bearing and friction pile. According to the destructive test results of the single pile and the regional experience, the back-calculated pile side friction and tip resistance is performed. The empirical value of the PHC pipe pile in the soft argillaceous siltstone of the pile side friction and tip resistance is recommended. It is suggested that the side friction and the tip resistance of strongly weathered argillaceous siltstone should be lower according to the recommended value in “Technical Code for Piled Building Foundations”. The lateral resistance of the moderately weathered argillaceous siltstone is recommended to be 200-260kPa, and the end resistance is recommended to be 7000-9000kPa.

Key words: PHC Pipe Piles, In-situ Axial Load Tests, Skin Friction, Tip Resistance, Argillaceous Siltstone