Study on Dynamic Response Features of Micro RPC Pile Based on Shaking Table Test

In order to study the influence of the relevant parameter of pile and soil on the dynamic response of micro pile foundation,a shaking table test on dynamic response of micro RPC pile is carried out. the acceleration time history reaction and strain time history reaction of pile-soil system as well as the distributions of the moment and deformation of single pile under dynamic load excitation are analyed. By analyzing the spectrum under the action of white noise,it is found that( 1) the natural frequencies of RPC micro pile exist near 5 Hz and 16 Hz,( 2) under the influence of repeated white noise,the compactness of sand increases,and the natural frequency of micropile increases too. By analyzing the acceleration response curve,it is found that( 1) the acceleration amplification under artificial wave is the most significant,followed by EI-Centro wave,Kobe wave is the smallest,because the action frequency of artificial wave is the closest one to the inherent frequency of the micro pile,( 2) under the action of sine wave with 4 Hz frequency and 0. 15 gamplitude,the maximum strain of the micro pile is located at the depth of 4 times of the pile diameter,( 3) under the action of sine wave with different frequencies,the maximum bending moment appears at the depth 0. 6 m,( 4) under the action of 3 kinds of seismic wave,the bending moment and deformation responses of artificial wave is the biggest,the action of EI-Centro wave is second,and the Kobe wave is weakest,because the frequency component of artificial wave is more abundant,the frequency of sine wave is single,while the frequency of seismic wave is rich,which makes the reverse deformation under the action of seismic wave more obvious.