Field tests on compressive bearing capacity of cast-in-situ pile and pre-bored grouted PHC pile

This paper presents a group of full-scale test results of cast-in-situ pile and pre-bored grouted pre-stressed high-strength concrete (PHC) pile (bored PHC pile) in deep soft soils. The pile shaft of cast-in-situ pile was arranged with strain sensors, and the bored PHC pile was arranged with both strain sensors and fiber optic sensors. The side and base resistances of bored PHC pile and cast-in-situ pile were analyzed according to the field test results. The research results showed that the 900 mm-diameter bored PHC pile revealed better compressive capacity compared to 1000 mm-diameter cast-in-situ pile. The side resistance of bored PHC pile was also greater than that of cast-in-situ pile due to the existence of grout body. The expanding base grout body of bored PHC pile also improved its base resistance, as the base grouting process could increase base area and improve the properties of soil around pile base as well. The field test results are valuable for the application of bored PHC pile and cast-in-situ pile in engineering practice.