Pile-soil-nuclear Island Model Dynamic Interaction Test And Numerical Simulation

In this paper,considering the characteristics of large mass and stiffness of nuclear power structure,through shaking table test of pile soil nuclear island dynamic interaction model and ABAQUS finite element numerical simulation analysis,the seismic response law and failure characteristics of nuclear power station pile foundation in non bedrock site considering motion interaction and inertia interaction are studied.The main tasks are as follows:1.Large scale shaking table tests considering the interaction of pile group motion and inertia are designed and carried out.The shaking table test scheme of soil pile foundation nuclear power structure dynamic interaction is designed,and the test model is completed;All kinds of sensors used in the test are calibrated to ensure the unity and reliability of sensor acquisition effect;This paper introduces the time domain and frequency domain identification methods of vibration system modal parameters,and uses the time domain identification method to identify the modal parameters of pile soil nuclear island model system.2.The seismic response law and failure characteristics of pile group foundation considering the motion interaction(PSI)and inertia interaction(PSSI)are analyzed.The results show that:(1)the inertial interaction plays a leading role in the distribution of dynamic bending strain and dynamic axial strain.(2)When psi and PSSI are considered,the acceleration response law of pile body and cap is basically the same;(3)The acceleration amplification factor is mainly affected by the dynamic load frequency.The higher the frequency is,the greater the acceleration response of the pile cap is.There is a minimum threshold(6Hz)for the response frequency of the pile cap to the dynamic load.When the input frequency is less than the threshold,the acceleration response of the pile cap is smaller.(4)Considering the inertial interaction,when the dynamic load frequency exceeds the response threshold,the pile cap will swing along the vibration direction,and it will increase with the increase of frequency and amplitude.3.The whole finite element method is used to establish the "soil pile group containment model" to simulate the shaking table test.The finite element modeling method and parameter values of pile-soil dynamic interaction analysis are discussed,and the rationality of the numerical model is verified by comparing with the experimental results.