Installation Resistance Calculation And Bearing Capacity Set-up Prediction Of Jacked Pile

The expansion of urban construction onto increasingly marginal sites makes the use of piled foundations become more and more popular. The jacked piling technique w-hich offers unique advantages including reduced noise, vibration and pollution is making the use of jacked pile an ever more attractive option for designers. But its theoretical research can not keep up with the need of application. This paper is based on theory study, recent field experiments and programming calculation. The penetration mechanism, settlement character and bearing capacity prediction are relatively deep studied in this paper. The main studies of this paper are summarized below:(1) This paper deeply studies of penetration mechanism and settlement character of jacked pile during installation process. Comparative Analysis of similarities and differences of penetration between jacked pile and static cone penetration test. the influence of friction material,penetration velocity and scale effect on penetration resistance are described, which will offer base and evidence for predicting penetration resistance using the CPT data more accurate.(2) Through a thorough review of the literature and the state of the practice, this paper analysis the mechanism of shaft friction fatigue ,summarizes the method of reducing penetration resistance and the use of shaft friction fatigue in project.(3) An empirical relationship between CPT data and penetration resistance is proposed to estimate installation resistance. According to this empirical relationship, a vb program has been worked out to do the calculation of data processing. The predictions of the installation resistance agree with in-site test in Taiyuan, showing that the method is feasible and effective.(4) A new BP neural network was designed to predict jacked pile bearing capacity set-up. A program compiled with visual basic language has been worked out to do the calculation of data processing. The predictions of the bearing capacity set-up are consistent with in-site test in ZhuHai, showing the method is feasible and effective.