Finite Element Analysis On Vertical Bearing Capacity Of Squeezed Branch Pile With Staggered Arrangement Plates

Pile foundation,as an effective method to deal with bad foundation,has been widely used in all parts of China because of its higher bearing capacity,smaller settlement and capable of adapting to complex geological conditions.With the change of pile material and the innovation of pile construction technology,a variety of pile type and pile forming technology have been designed successively.The squeezed branch pile is one of the most prominent bearing properties.The design concept is rooted in the root of the tree,and the characteristics of the contact surface are enlarged by using the root structure,and the bearing plate is installed at the appropriate position of the pile body to improve the bearing capacity of the pile body.The squeezed branch pile has the advantages of high bearing capacity,good pullout resistance,cost saving,short construction period,and stable and fast piling process.In this paper,based on the existing research status of single pile and pile groups in squeezed branch plate,the bearing characteristics of the single pile are clearly understood.The numerical simulation software is used to simulate the in-situ test,and the results are compared with the original pile to verify the numerical simulation.On the basis of single pile model,the bearing capacity of double pile and group piles under the condition of flat plate and dislocated plate is further studied.The results of the study show that:1.The bearing capacity of the pile is characterized by the property of the friction pile in the pile part and the end bearing property in the part of the bearing plate,and the bearing capacity of the upper and lower bearing plates is gradually shown in the process of increasing load.The bearing effect of the pile tip is not obvious,which accounts for about 7%-8% of the total load.2.Under the layout of single pile,the adjustment of the upper plate does not affect the bearing behavior of the pile,and the position of the pile can be adjusted properly in the construction.The adjustment of the lower plate has a great influence on the pile body.The better the bearing capacity is,the better the bearing capacity of the pile is.3.Under the condition of double pile flat plate and the wrong dish layout,the settlement of the pile body in the wrong dish is obviously smaller than the flat plate layout.The arrangement of the wrong plate has no significant influence on the footwall,pile ends and side friction of the double piles,and there are obvious differences only in the upper bearing plate.The concrete performance is that the pile body of the upper plate has better bearing capacity in the initial stage of load.The pile body of the upper plate gradually surpasses the load increasing process.When the control point is reached,the two piles bear the same load,and the load sharing ratio is less than the flat plate arrangement,which indicates that the disks arrangement can reduce the load of the disc body and improve the bearing capacity.4.In the group pile model,the axial force of the pile,the side and the corner pile is different,showing the trend of increasing in turn,and the settlement is also different,showing the trend of decreasing in turn.The reason for this phenomenon is that the pile body is affected by the pile group effect,and has smaller bearing capacity and greater settlement characteristics in the areas with greater influence.5.Under the condition of the group pile flat plate and the wrong dish on the upper plate,the pile body arranged in the wrong dish shows obvious superiority in settlement.The pile group placement does not change the bearing capacity of the side friction of the pile,but it reduces the proportion of load sharing and optimizes the bearing proportion of the middle pile at the upper bearing plate,so that it can bear more load under the group main effect.It is a more reasonable arrangement.