Research On Soil Plugging Effect On Bearing Capacity Of Prestressed Concrete Pipe Pile

Prestressed concrete pipe pile is widely used in the 80's of 20th century, and it is a special type of prefabricated concrete pile. This type of pile has many advantages, such as simple technique, better quality, fast construction low cost and convenient detection, so it has been widely used in geotechnical engineering. Though with the above merits, its soil plugging effect of pile driving still need to be further researched,and its design theory need to be further perfected. In the paper,based on the soil plugging effect,it also analyzed the behavior of stress and its unique mechanism of bearing in details.It also illustrates that the soil plugging effect is the main reason for the enhancement of the vertical bearing capacity of a single prestressed pipe pile.The results of both experimental and theoretical investigation of the soil plugging effect are introduced. Then the soil plugging effect of prestressed concrete pipe pile are discussed. Based on the soil plugging effect, the numerical analysis model is established by FLAC3D.And the squeezing effect of prestressed concrete pipe pile are discussed. Because of the influence of soil plugging effect on the vertical bearing capacity of PC,this paper count and conclude large quantity cases of static load test results and analysis the difference between the practical and designing bearing capacity.Propose the concrete pipe pile bearing capacity of single pile limit value correction formula of'Building pile technical specifications'(JGJ94-2008).Through the contrast of calculation result and measured result,the author verifies the practical significance of the revised formula.It hopes that this paper will supply some reference value and helpful for the design of PC in the later.This paper discusses the results of both experimental and theoretical investigation of time effect on bearing capacity of statically pressed pile.The mechanism of time efect on bearing capacity is analyzed, and relation curve of bearing capacity and time is obtained by using curve fitting method to handle re-pressure test data and numerical model.According to this relation curve,increase tendency of bearing capacity with time is represented in sandy and cohesive soil.