Dynamic response analysis of single slope under oblique incidence of seismic P wave
The distribution of landslides induced by earthquakes present the characteristic of'back slope'effects,which indicates that the incident direction of the seismic wave greatly influences the dynamic response and instability of the slope.However,the study of slope dynamic response under oblique incidence is not sufficient.Based on the theory of elastic wave in the time domain and viscous-elastic artificial boundary conditions,the oblique incidence of the P wave is realized by programming with Fish language,which is embedded in the Fast Lagrangian Analysis of Continua 3D(FLAC3D)software.The accuracy of the oblique incidence of the P wave method is verified by comparing a case with the theoretical solution.The dynamic response of simple harmonic waves,windowed simple harmonic waves,and natural seismic waves to a single slope excitation is studied.Meanwhile,taking the windowed simple harmonic wave as an example,the dynamic response characteristics of a single slope(the slope height is 90 m)under the influence of input wave frequency and incident angle are explored.The results show that the peak acceleration value of the head and tail of the slope shoulder under the action of the harmonic wave is more than 1 times that of the middle stable section as the impact effect of the non-zero velocity of the head and tail of the input wave.The acceleration response of simple harmonic waves and windowed simple harmonic waves to the same part of the slope surface is stronger than that of natural seismic waves.Under the action of the 20° incident angle of the windowed harmonic wave,the horizontal acceleration distribution of the slope changes more significantly with the input wave frequency than the vertical direction.When the input wave frequency is 10 Hz,the peak acceleration of the slope shoulder position reaches the maximum,which is about 3.33 times of the input wave amplitude.At this time,the slope height is consistent with the critical height of the vertical amplification of the slope dynamic response.The change of vertical acceleration distribution of slope is higher than that of horizontal direction under different incident angles of the windowed simple harmonic wave with a frequency of 2.5 Hz.When the incident angle is 60°,the peak acceleration at the shoulder position reaches the maximum,which is about 3.12 times of the input wave amplitude.The research shows that the influence of seismic waves on slope dynamic disturbance will be underestimated when it is vertically incident.
Flac3DNumerical simulationP wave oblique incidenceDynamic response of slope
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