Pile-Soil-Structure Dynamic Interaction Test And Numerical Simulation

In this paper,the pile foundation-core island structure of non-base rock site is taken as the research object,and the pile-soil-structure seismic simulation test and numerical simulation are designed and carried out.Aiming at the characteristics of large stiffness and large mass of the upper nuclear power structure using pile foundation on the non-bedrock site,a pile-soil-structure test model of large-scale seismic simulation shaker was designed and produced;it provided a basis for the reasonable deployment of various sensors,The pile-soil-structure shaking table test model was numerically simulated.In order to study the seismic failure mechanism of the pile foundation of the nuclear island structure,the low-cycle horizontal reciprocating loading test was used to study the influence of the reinforcement ratio of the pile foundation and the concrete label on the strength of the pile foundation.The following main tasks were carried out and completed:(1)Designed and produced a single pile-soil-structure shaking table test model,and completed a multi-operating shaking table model test.Use fine-grained concrete to make the pile foundation model;design the nuclear island structure instead of the model according to the characteristics of the upper nuclear power structure,and design and prepare the model soil;select the synthetic ground motion based on the RG1.60 spectrum and two actual seismic records as the test input ground motion.Through the analysis of the test results of multiple working conditions,the dynamic interaction law of pile-soil-structure under seismic load is studied,and the quality,stiffness,input amplitude and frequency spectrum characteristics of the superstructure on the pile-soil-structure system are analyzed.influences.(2)The ABAQUS software was used to calculate and analyze the test model,and the effects of superstructure quality and stiffness,input load period,input seismic frequency spectrum characteristics,and layered soil on pile foundation seismic response were studied.The calculation results show that as the input pulse period decreases,the mass of the superstructure increases,and the stiffness decreases,the pile bending point moves toward the pile top.With embedded piles at the ends of the cap,under the action of seismic load,the internal force envelope of the pile body is distributed in an "X" shape,and the shear bending moments at the top and bottom of the pile are large.When the mass of the superstructure increases and the rigidity decreases,the internal force of the pile body increases.The soft-hard soil boundary will lead to sudden changes in the internal force of the pile body.(3)In order to meet the study of the pile-soil-structure seismic simulation shaking table pile foundation failure mechanism,three types of pile foundation models with reinforcement ratios were designed.The low-cycle horizontal reciprocating loading test was used to study the amount of pile reinforcement on the pile The influence of the strength,and the detailed analysis of the pile failure shape,pile energy consumption,pile body stiffness degradation,pile body bending moment distribution,etc.,and the configuration of the pile foundation model in the subsequent shaking table test of group pile seismic simulation Reinforcement ratio and concrete strength index.