Study On Mechanism And Application Of Post Grouting Technology Of Bored Pile

Since the bored pile come out, it has widely used in high-rise buildings, industrial buildings, bridge pier in pile foundation engineering in large projects. However, as the problem of sedimentation on the bottom of piles and mud around the shaft of bored piles, it causes the bad effect of the bearing performance of bored piles. As a result, people are targeted to develop post grouting technology to solve the sedimentation on the bottom of piles and mud around the shaft of bored piles.Through a large number of engineering research shows that post grouting technology can greatly improve the bearing capacity of pile foundation and decrease subsidence, it has been more and more widely used in the practical engineering.But post grouting technology in the theoretical research development far behind the practical engineering situation. People offen study the final effect of the post grouting technology, but people less study the effect of the reinforcement and mechanism of post grouting at different ages. It must strengthen the study on the reinforcement of post grouting at different ages in order to provide the basic theory for post grouting technology in practical engineering.This paper from the macromechanics and micromechanics aspects study the post grouting bored pile lateral soil strength growing rule at different ages, which through the specil pile soil shear test and the scanning electron microscope(SEM) test. It combined with the pile static load test of a high-rise residential buildings and residential buildings settlement observation test, and add the numerical analysis, which can systematic research on the reinforcement effect of post grouting technique at different ages.The main contents of the paper as follow:(1) It can study the post grouting bored pile lateral soil strength growing rule at different age through the special shearing test soil of pile. Through study the lateral soil strength growing rule of dry hole bored piles and slurry-supported bored piles with post grouting at different ages, which analysis the bearing performance of the bored piles with post grouting technique.(2)It by contrast at different ages with post grouting and without post grouting the slurry-supported bored piles lateral soil strength growing rule, which analysis the bearing performance of the slurry-supported bored piles with post grouting technique.(3)The sample section microstructure characteristics at different age were observed by scanning electron microscope.Then analysis on the change of sample microstructural features at different ages and according to the age analysis of its strength growing rule.Finally through using the chemical mechanism of strengthening to analysis the microcosmic mechanism of the post grouting bored pile lateral soil strength growing rule at different ages.(4)It analysis on post grouting technique on the bearing performance of the slurry-supported bored pile, which through the unit of A high-rise residential building with post grouting technique and the unit of B high-rise residential building without the post grouting technology static load test of slurry-supported bored pile foundation as well as through the long-term settlement observation of the unit of A and B high-rise residential building.(5)It can simulate the final settlement of the unit of A and B high-rise residential building, which by using the finite element software ABAQUS. It can also simulate settlement the A and B high-rise residential building in different periods, which by using the FORTRAN language.It can analysis on the numerical results compared with the measured results at construction site.