Study On Pull-out Performance Of A Kind Of Anchor Static Pressure Pile Welded Joint

There is often groundwater in the deeper strata of the city,which will produce buoyancy to the underground structure of buildings.in order to prevent the floating damage of building structure,anti-pull-out piles are often used to resist buoyancy in engineering.In most cases,the whole long pile can not be prepared at one time,it needs to be precast in stages,and then connected into a whole pile through pile joint in the process of pile driving or pile pressure.therefore,the pile joint plays an important role in the pile foundation as a whole.At present,there are many kinds of pile connection,but the most widely used and mature pile connection in our country is still welding.In this paper,a new type of anchor static pressure pile welded joint proposed by our research group is taken as the research object,and its pull-out performance is analyzed and studied in detail.The specific process is as follows:(1)The large-scale general finite element software ABAQUS is selected to carry out the numerical simulation test.by selecting the appropriate material constitutive model and based on the nonlinear analysis function of the software,the finite element analysis model of anchor static pressure pile welded joint is established,and a set of simulation method is formed to study the pullout performance of anchor static pressure pile welded joint.And refer to the experimental data of related research to verify the accuracy and reliability of the numerical simulation method in this paper.(2)The pullout performance of two kinds of common anchor static pressure pile welded joint specimens and the new anchor static pressure pile welded joint specimens proposed by our research group are compared by numerical simulation,and the differences in pullout performance of each welded joint specimen are analyzed in detail.(3)The test scheme is designed according to the key parameters such as the diameter of main steel bar,the thickness of pile end plate,the thickness of square steel pipe,the section size of square steel pipe and the arrangement of reinforcement of pile body,and the numerical simulation tests are carried out under the action of tensile force.the effects of structural parameters such as diameter of main steel bar,thickness of pile end plate,thickness of square steel tube,section size of square steel tube and arrangement of reinforcement on the pullout performance of welded joints of new anchor static pressure pile are discussed.And then put forward the corresponding design suggestions.(4)In order to study the influence of welding construction error on the pullout performance of new anchor static pressure pile welding joint,the experimental scheme is designed according to the welding rotation angle and welding offset,through the numerical simulation test,the effects of welding rotation error and welding eccentricity error on the pullout performance of joints are discussed.(5)Finally,summarize the research results of the full text,extract the conclusions and put forward personal prospects for the follow-up research.