Abstract：Research purposes: The dynamic effect of train load can cause elastic deformation and cumulative settlement of the subgrade, which can even lead to structural damage in serious cases. Build the vibration equipment based on a linear source biaxial motor. By adjusting the eccentric mass, device counterweight and input frequency, and regulating the vibration load output, this paper carries out calibration tests on the dynamic effect of the excitation equipment,analyzes the change rule of peak stress σp and valley stress σv relative to the static equilibrium stress σ0 with the eccentric mass and rotational speed of the motor, and discusses the upper and lower limit frequencies for the stable operation of the excitation equipment. Research conclusions:(1) With the increase of the number of eccentric piece group i and vibration frequency f, the output dynamic stress σ of the excitation equipment is allometricl function growth trend, obeying the relation σ=Ai fBi, and dynamic equilibrium stress (σp+σv)/2 is greater than the static equilibrium stress σ0, the difference with the increase of f gradually expands. (2) The motor input frequency increases, the phase difference of the reverse rotation of the eccentric piece of the two-axis motor gradually decreases, and the error rate q and f of the vibration stress σpv=σp -σv relative to the static equilibrium stress σ0 are positively correlated. (3) Calibration test is carried out under the design dynamic load σpv≈100 kPa of the subgrade, and the deviation rate between the estimated and tested values of the fitted equation is in the range of -17.9%~8.7%. (4) The research results can provide a reliable basis for simulating the dynamic action of railway subgrade and understanding the dynamic characteristics of railway subgrade in the excitation test.
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2022, Vol. 39 
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