Abstract—Strength composite pile is a new type of pile foundation in which pre-stressed high-strength concrete (PHC) pipe piles are embedded in cement-soil piles. It is an important technical means to realize green and low-carbon construction. In order to study the bearing capacity of strength composite pile in offshore foundation soil, the vertical static load test of strength composite pile and corresponding PHC pipe pile was carried out based on the site of Nantong Yanglv Railway project. By comparing the field test results of these two pile types, the reinforcement mechanism and deformation law of strength composite pile were discussed. The results show that the ultimate bearing capacity of the composite pile is significantly higher than that of the PHC pipe pile, and the vertical bearing capacity is increased by 48 %. The pile side friction is increased by 2 times, and the pile tip resistance is only 7.03 %, which belongs to the friction pile. The dry/wet construction technology has a certain influence on the stiffness of the pile head of the strength composite pile. The dry-method pile performs better in the silty clay layer with high water content, and the side friction is twice that of the wet pile, which gives full play to the bearing performance of the shallow soil. In the future engineering design, this pile foundation form can be used to further optimize the pile length.

Keywords—strength composite pile, field test, ultimate bearing capacity, side friction, construction technics

Cite: Xinsheng Chen, Guoliang Dai, and Hongbo Liu, "Experimental Investigation on Bearing Capacity of Strength Composite Pile," International Journal of Structural and Civil Engineering Research, Vol. 14, No. 1, pp. 23-28, 2025.