Coast Construction of Large Diameter Open Steel Pipe Pile Driving Analysis and Bearing Properties Research

Large diameter open steel pipe pile is proposed to be used for the foundation pile of a power plant wharf project. In order to obtain the design and construction parameters of engineering pile, the pre-construction test pile was carried out. During the test, the stress and deformation characteristics of steel pipe piles at different ages are comprehensively tested and analyzed by means of high strain dynamic test, static load test pile internal force test and so on. The results of pile test research are as follows: (1) The bearing type of test pile is determined as friction pile by counting the proportion of end resistance; (2) By observing the difference of soil surface inside and outside the pile pipe and combining the characteristics of end resistance deformation curve, it is determined that the test pile has pile end clogging effect; (3) The static load internal force test shows that with the continuous increase of load, the exertion degree of end resistance increases rapidly step by step, the soft weakening area of friction resistance appears in the section of 0~12 m, and the whole loading process of other sections shows an enhanced state; (4) The prediction formula of the final bearing capacity of steel pipe pile is obtained by synthesizing the relationship curve between the number of blows and bearing capacity and the relationship curve between age and soil recovery coefficient of the upper 3 m pile.