Research On Bearing Capacity Behavior Of Sloping Pre-stressed Pipe-pile

With the technique of pre-stressing force and centrifugal technique, a new type of pre-stressed concrete pipe-pile has been presented. It is extensively used nowadays in the cities in which soft clay foundation is common because of its various advantages. However, it is often sloping in soft clay during driving piles. The vertical bearing capacity of the sloping pre-stressed concrete pipe-pile is different with the vertical pre-stressed concrete pipe-pile. There is less research about the bearing capacity behavior of the sloping pre-stressed single pile and the sloping pre-stressed pipe-pile group. It is puzzling scientific researchers and engineers about how to evaluate bearing capacity behavior of the sloping pre-stressed pipe-pile correctly.Firstly, in this paper, the bearing capacity behavior of the sloping pre-stressed single pipe-pile is studied. Based on numerical analysis, Bowles method is improved by employing the load transfer function of pile shaft soil. The program is designed in the software of FORTRAN. The influencing factors on bearing capacity behavior of the sloping pre-stressed single pipe-pile has been studied by employing the program. The result indicates that the bearing capacity of the sloping single pile not only has relation with the sloping situation, but also has relation with the soil nature. A conclusion can be made that 1% of slope given by specification about pipe-pile is not perfect.Secondly, the software ANSYS was used to build the mechanical model for the sloping pre-stressed single pipe-pile. The computational results of mechanical model in various soil agree well with the computational results of program. It is reasonable for us to employ the mechanical model to research the behavior of the sloping pre-stressed pipe-pile. Moreover, the influencing factors on bearing capacity behavior of the sloping pre-stressed pipe-pile group has been studied by employing the program and some guidable conclusions are obtained.Finally, the author has analyzed the difference of bearing capacity behavior between the sloping pre-stressed single pipe-pile and the sloping pre-stressed pipe-pile group. The result indicates that it is rather different about the bearing capacity behaviorbetween the sloping pre-stressed single pipe-pile and the sloping pre-stressed pipe-pile group. Therefore, some guidable measures than can guide the engineers to reinforce and process the sloping pre-stressed pipe-pile are obtained. The results will be helpful for engineering application and more research about the behavior of the sloping pre-stressed pipe-pile.