Application of high-strain testing in large-diameter steel pipe pile project in Rudong sea area

Based on the initial and repeated high-strain test data of three large-diameter open steel pipe piles in Rudong sea area of Jiangsu Province, a pile end reduction coefficient η applicable to the sea area and the formula for calculating the recovery of bearing capacity is proposed, and a technical basis for evaluating the bearing capacity of large-diameter steel pipe piles in the sea area is provided. According to the high-strain test data of open steel pipe piles, the recovery coefficients of the lateral resistance of the test piles are much greater than those of the end resistance, and the lateral resistance of the piles increases significantly over time, but the increase in the end resistance is very small. Based on this, it is recommended to use the pile end resistance reduction coefficient η= 0.05 for large-diameter open steel pipe piles in the Rudong sea area. In addition, by exploring the recovery and growth mechanism of pile foundation soil, a formula for calculating the recovery of pile foundation bearing capacity is proposed, and the verification error is within 10%.