Analysis And Research On Vertical Bearing Characteristics Of Strength Composite Piles

The strengh composite pile is a kind of pile which is composed of the Bulk pile,flexible pile,rigid pile pile by two or three kinds composite construction.Engineering practice shows that the composite pile has the characteristics of stable and reliable pile quality,high bearing capacity,low cost,convenient construction and less pollution,and has a wider potential market.In the paper we will introduce the combination of cement soil pile and prestressed high strength concrete pipe pile(PHC).In this paper,we will combine the three methods that theoretical analysis,engineering examples and finite element simulation to study the stress characteristics of the vertical load on the top of the composite pile.We have done some work and introduced the following:(1)To anlysis the stress characteristics we compared the result of ABAQUS finite element simulation with the pile test data of a residential projiece in Fuyang,Anhui.Compared with the Q-S curves obtained by static load test,the simulation results are slightly smaller than the experimental data,but the overall trend is consistent.It can verify the rationality and correctness of the finite element model of stiff composite piles established by ABAQUS.(2)The model of PHC pipe pile and cement soil mixing pile are established by ABAQUS finite element simulation software to compare with the composite pile model.The results showed that without core pile,the load transfer ability of the soil cement pile is greatly reduced.Because itself strength is low to bear the whole load,the Q-S curve shows aggressive destruction;comparison of PHC pile Q-S curve and the strength of the composite pile gap is not large,but the advantage of PHC bearing capacity of single pile high strength composite did not play out;The composite loading pile combines the characteristics of the two piles to form load transfer mode,from core pile to cement soil pile then to surrounding soil.More reasonable load distribution effectively improves the bearing capacity.(3)Set up different elastic moduli of pile end soil,pile side soil and cement soil pile of the model,we got the proposed value range of modulus of elasticity of cement soil pile under certain geological conditions;and by discussing the influence of pile end soil and pile side soil on the behavior and settlement of the composite pile,we find that the property of the pile side soil has greater influence on the settlement of thepile than the pile end soil.