why the horizontal displacement keeps increasing in my CPRF model under seismic loading?

I have modelled one combined piled raft foundation using raft as plate and pile as embedded beam element and applied one sinusoidal loading with frequency 1 Hz and acceleration amplitude 1 m/s2 for 30 second interval at the soil model base in surface prescribed displacement with positive ux = 1. but in the result the whole soil model is getting displaced by some 3 m amount in positive x direction. here i have taken viscous boundary condition in X and Y direction and None in Z direction. How can I fix this problem?

Parents Reply Children
No Data