Research On Influence Factors And Stability Of Compaction Reinforce Of Large Bored Pile Hole Wall

Pile foundation is one of the main foundation reinforcement works which can improve the overall stability of the foundation and the capacity of the foundation.According to the construction method,the pile can be divided into soil compaction pile,partially compacted pile and non compacted soil pile.Among them,non compaction of bored pile soil pile have been widely used in city buildings with many advantages such as high bearing capacity,soil compaction,construction of no damage,low noise and suitable for the use in urban buildings intensive areas.But,there are many problems in the construction of bored pile,because its construction is carried out in the underground,which belongs to the hidden works,and the stability problem of the hole wall is particularly prominent.Borehole wall stability is affected by many factors and conditions.The stability of bored pile hole wall is affected by many factors and conditions,such as the structure and properties of strata,groundwater seepage,the retaining mud,drilling technology and construction machinery,etc.In this factors,the structure and properties of strata are the key factors to determine the stability of the hole wall of the filling pile,improving the structure and properties of the foundation soil can effectively improve the stability of the hole wall and prevent the collapse of the hole in the process of hole,the retaining mud and construction machinery under certain conditions.At present,the most commonly used method for improving the soil structure and properties is the dynamic compaction method.Using dynamic compaction technology to improve the properties of reinforced foundation has become an important way to solve the problem of borehole wall stability and to prevent and control the collapse disasters.Combined with Guangdong petrochemical engineering project,this paper further analyzes and summarizes the characteristics and distribution laws of borehole collapse in the construction of bored pile based on the analysis of the data of the field pouring pile.This paper determines the size of the influence factors of the pore wall based on grey relational analysis;analyses the influence of dynamic compaction parameters on the physical and mechanical indexes of soil mass based on the dynamic consolidationmechanism and the principle of polynomial regression analysis;studies and establishes the evaluation model of mechanical analysis of anti collapse force and induced collapse of bored pile;and determines the instability criterion of borehole wall stability of bored pile.Based on this study,this paper analyses and studies the variation law of borehole wall stability under different conditions of dynamic compaction foundation using the finite element software ABAQUS.The main research contents of this paper are as follows:(1)This paper selects 10 bored piles in Guangdong petrochemical project,apertures pile hole depth,the vertical sediment thickness in drilling construction site Through the detection of bored pile into the quality of the special equipment JJC-1D type perfusion pile aperture detection system,to further analyze and summary the characteristics and distribution laws of borehole collapse in the construction of bored pile.(2)Based on the principle of grey relational analysis,this paper establishes the grey relational analysis model of the evaluation index of the stability of the hole wall of the filling pile,determines the evaluation index of the influence of the stability of the hole wall of the filling pile.This paper obtains the correlation coefficient of each evaluation index,determines the magnitude of the association,and then determines the effect size of each evaluation index on the stability of the hole wall.(3)This paper analyses dynamic compaction,dynamic consolidation,dynamic displacement and dynamic consolidation mechanism of vibration wave compaction systematically,carries out dynamic compaction test with different dynamic energy on the basis of the principle of polynomial regression analysis;according to the basic data of each index of sand after compaction,analyses the influence laws of dynamic compaction parameters on the physical and mechanical indexes of soil mass.(4)According to the basic theory of elastic plastic mechanics,this paper studies the complex mechanism of the pore forming of the filling pile;establishes a mechanical evaluation model for the analysis and evaluation of the anti collapse force and induced collapse of bored pile,determines the instability criterion of borehole wall stability of bored pile.(5)Combined with the formation parameters of the three joint zone of Guangdong petrochemical project,this paper analyses and studies on the influence of the energy of dynamic compaction,compaction frequency and interval time on the stability of the hole wall of the filling pile,and systematically analyses and studies on the influence of dynamic compaction parameters on the deformation laws of borehole wall using the finite element software ABAQUS.