Seismic stability time-frequency analysis theory resolution of reinforced retaining wall

A large of research results show that there are more significant effect of the duration time and frequency on seismic stability of reinforced retaining wall. However, the common methods are pseudo-static method and limited displacement method at present, which can not consider the duration time and frequency of input wave. Therefore, based on the elastic wave theory, this paper summarizes the dynamic analysis model of the reinforced retaining wall, establishes the force equilibrium differential equation by horizontal slices analysis method, puts forward the time-frequency analysis method of the seismic stability of reinforced retaining wall under the action of earthquake by Hilbert-Huang transform, which can provide some valuable references for the time frequency seismic design of the reinforced retaining wall and other retaining structures. Research conclusions: (1) A time-frequency analysis method of the internal anti-seismic stability analysis of the retaining wall is proposed considering the three elements of seismic waves (peak, frequency and duration). (2) The influence of the lacing wires types, the seismic intensity, internal frictional angle of the filling earth and the frequency of the input earthquake wave on the needed total tensile force of the lacing wires is analyzed, which is that the needed total tensile force of the lacing wires increases with the increase of the seismic intensity and the decrease of the internal frictional angle; the needed total tensile force of the expandability lacing wires is bigger than that of the non-expandability lacing wires; the needed total tensile force of lacing wires is distributed in the shape of saddle and the force achieves the maximum value when the frequency of the input wave is the same as the natural frequency of the reinforced retaining wall. (3) If the reinforced retaining wall is designed according to the rules considering only the peak ground motion not input wave frequency, the emergency capacity of the reinforced retaining wall will be reduced. (4) The active crack angle gradually increases with the increase of internal frictional angle, however, the active crack angle of earth filling behind retaining wall gradually decreases with the increase of internal frictional angle. ©, 2015, Editorial Department of Journal of Railway Engineering Society. All right reserved.