Research On Design Theory Of Prestressed Pipe Pile And Its Application In Engineering

As a main type of pile-foundation ,prestressed concrete pipe pile foundation has been widely used in many kinds of projects because of its advantages of ease construction, high quality ,high adaptability and good behavior of anti-seismic. There is wide developing foreground for pre- stressed concrete pipe pile foundation. In some littorals provinces ,such as Guangdong, Fujian province , pipe pile is at major status on the design selection of pile types. Since 2005 pre-stressed concrete pipe pile has used extensively at Northwestern of Hunan province. As the time of pipe pile's use of pipe pile is not too long, there are still many problems in research and applications .The design of prestressed piles in the region is still in the experience phase, and it is difficult to accurately determine the bearing capacity of pipe piles. Also,there are still many problems in prestressed concrete pipe pile design and construction. Base on the problems above-mentioned, some work have been done as following:Firstly, the working mechanism of prestressed pipe pile has been systematic analyzed and discussed on the basis of the pile load transfer mechanism; Secondly, the vertical and horizontal bearing capacity calculation methods of prestressed piles have been comprehensively expounded base on the engineering geological characteristics of northwestern of Hunan province .And more,the method of determination of vertical bearing capacity of pipe pile in multi-storey soil by the settlement of pile top has been proposed. And than, for the problems of prestressed pipe pile in construction process and quality in detection, the notes should be attended in the whole construction process and quality testing have been conducted in-depth from the mechanism of hydrostatic pile's penetration. Lastly , through the analysis of concrete pipe projects in northwestern region , the solutions of actual pipe pile ultimate bearing capacity calculated by the way of this paper are more reasonable than the settlement using by standard. Thus, a simple and quick, accurate and reasonable approach has been found which is suitable for estimating vertical bearing capacity of pipe piles in northwestern region of Hunan province, As well as provided a reliable basis to make up for the inadequacy of regional norms for the design and construction.