The Finite Element Simulation And Research In The Progress Of Underwater Concrete Perfusion Of Cast-in-place Pile

There has been50years of history since the advent of cast-in-place pile. It not onlyappears in an early time, but also has been widely applied, but pile concrete quality accidentcaused by improper operation when pouring concrete also emerges in endlessly. Based on theANSYS, this paper simulates the perfusion process of underwater concrete in cast-in-placepile to improve the constructor’s understanding of the underwater concrete perfusiontechnology, which plays an important guiding role in reducing the concrete quality accident.This paper reviews the development history of cast-in-place pile, points out the researchpurpose and the meaning of this topic. According to the theory of water hammer pressure, thispaper explains why the pipe are ruptured easily when jittering pipe to assist pouring concrete,describes characteristics of pipe fracture in detail, indicates the effective way to avoid piperupture. This paper researches the piping phenomenon which is observed in the constructionsite, points out the forming reason of piping in cast-in-place pile and its serious harm, putsforward the measure to avoid piping phenomenon. On the basis of understanding traditionalreperfusion deeply, this paper improves the traditional reperfusion technology, designs a set ofsimple device and convenient construction method. The improved reperfusion technologyavoids forming a layer of loose weak concrete in pile. Before the initial curdle of pile concrete,the improved reperfusion technology can save significant economic losses to handle pileperfusion accident. This paper uses ANSYS to simulate the perfusion process, researches theimpending height and shape of the bore bottom on the influence of concrete perfusion, findsout that a lot of bad concrete in the vortex area reduces the quality of the concrete at thebottom of pile, illustrates that the constructor jacking up the pipe’s impending height atrandom and irregular shape at the bottom of the bore effect pile bottom concrete qualityseriously. According to the theory research and practice, puts forward the reasonable pipeimpending height, suggests eliminating cone and steps bore bottom and popularizingstreamlining bore bottom. This paper uses ANSYS to simulate the concrete perfusion processin the middle of pile, puts forward the reasonable unloading concrete methods when pouringunderwater concrete in pile, points out the embedded depth of pipe on the influence ofconcrete quality in the middle of pile, finds out that the pile concrete between the bore walland pipe outer wall forms highlight parts and concrete rises in the form of oscillation, explainswhy the quality of concrete nearby the bore wall and pipe outer wall is poor, summarizes a setof methods to improve the quality of concrete in the middle of pile. This paper analyzes howthe sludge forms in the top of the pile, searches the interaction process between the concrete atthe head of pile and the sludge, points out that the interaction between the concrete at the headof pile and the sludge is fuelled by oscillation process. Combined with site constructionexperience, this paper summarizes a set of effective methods to ensure the quality of concretein the top of pile. On the basis of in-depth understanding of perfusion concrete, this paper dividesperfusion concrete area into the fixed area, rose area and the vortex area, divides the way ofconcrete rising into the piston type and overturn type, researches the transformation processbetween the two types of rising, points out that the piston type is easy to clamp mud and sandin the position of bore wall, the overturn type is easy to entrap sludge inside the pile concrete.