Comparative Study On Compaction Effect Of Variable Cross-section Precast Concrete Pipe Piles

Precast concrete pipe pile as a kind of simple construction, reliabletechnology, low cost of precast pile type, widely used in engineering. Sofar, the prefabricated concrete pipe pile are all in the civil engineeringsection pipe pile, and the construction technology and design calculationof matching based on the theory are also based on cross section, such aspipe pile. Due to uniform the pipe pile in pile body stress on thecharacteristics and the application of concrete material are there are manyunreasonable places, so this topic on the basis of considering the abovefactors put forward the new pipe pile cross-section of precast concretepile. In order to understand the variable cross-section pile drivingcharacter of pipe pile, promote the engineering application of the variablecross section pile, this topic through the indoor experiment, combiningtheoretical derivation and numerical calculation method, Pile drivingeffect has carried out some research on its:first of all, this article through to the research achievements ofpredecessors’ research that the pipe pile is the summary and analysis ofthe proposed method used in the study of this topic and research content.Secondly, the variable cross-section pile and the cross section of pipepile such as indoor model pile test, get the pile penetration resistance andthe relationship between pile capacity. Amount of uplift of soil aroundpile curve and radial displacement diagram, carries on the contrastanalysis, summary of variable cross-section pile with different crosssection pile, etc.Again, based on cavity expansion theory and Vesic theory to analysisof variable cross section pile pile driving effect, and the variablecross-section pile penetration resistance of pile, pile end resistance andsoil horizontal displacement formula of theoretical derivation, anddeduces the formula to calculate value contrast analysis with test data,verify the correctness of the calculation formula is derived, and therebyimprove the design theory of the variable cross-section pile.Finally, using the Flac3Dnumerical simulation of pipe pile pile driving effect, based on the finite element software in the simulationprocess takes into account the constitutive model and large deformationproblem, the displacement penetration method such as simulation, theresults consistent with indoor model test is the basic, verify the feasibilityof test.In this paper, the research found that variable cross-section pile inthe soil compaction effect is a smaller cross section pile, such as the pilepenetration resistance per unit volume is larger, the design of variablecross section pile and construction laid a theoretical and experimentalbasis.