The Seismic Response And Dynamic Stability Of Weak Interlayered Slope With Frame-anchor Reinforcement

The frame-anchor reinforcement has been widly used in slop engineering and is especially suitablt for the reinforcement of the weak interlayered slop.However,the research on the seismic response and seismic stability of weak interlayered slope with frame-anchor reinforcement is still very few.Basing on the shaking table model tests and the numerical simulations,the seismic response,dynamic property and failure mechanism of weak interlayered slope with frame-anchor reinforcement are carefully studied in this article.The seismic responses of acceleration,earth pressure,displacement,the anchor cable axial force are focused in this article.The influences of slope elevation,seismic amplitude and seismic type upon these seismic responses are thoroughtly discussed.Meanwhile,the dynamic safety factor of typical slope of Zhangzhou Zhaoyin expressway under different seismic is calculated by introduce the strength reduction method into the dynamic history analysis.Considering the horizontal seismic action and the anchor-frame reinforcement,the seismic stability analysis method based on general slice principle is proposed for the anchor-frame reinforced slope.The main conclusions are listed as follows.1)The amplification coefficient of peak ground acceleration increases non-linearly with elevation and the whiplash effect is observed evidently.However,the existence of weak interlayer changes the performance of elevation effect in the vicinity of interlayer and the isolation effect is observed especially under the scenario of large amplitude excitation.2)The new oscillation coefficient of peak earth pressure(PEP),which is defined by the proportion of additional peak horizontal earth pressure to the static earth pressure,is proposed in this article.The PEP oscillation coefficient increases with the seismic amplitude non-linearly,and decreases with the cover depth.The positive and negative oscillation coefficients of peak earth pressure are basically equaled under the excitation of small amplitude.Under the lager amplitude excitation,however,the minimum response of earth pressure tends to zero(almost detached)and the maximum response of earth pressure reaches 4-7 times of static one.3)The frequency-domain analysis of acceleration shows the evelation effect and peak earth pressure of WC wave are greater than other waves.Since the WC wave is abundant with high-frequency component,whose predominant frequency is close to the natural frequency of slope.The component of frequency of seismic wave has great change during the wave propagating from slope bottom to slpope top.The double peak phenomenon occurs,which means two frequency components are amplified significantly.4)The dynamic safety factor of frame-anchor reinforcement slop under different seismic can be calculated by introduce the strength reduction method into the dynamic history analysis.It si concluded that the dynamic safety factor is influenced by the seismic amplitude and the seismic type significantly.5)The seismic stability analysis method based on general slice principle is proposed for the anchor-frame reinforced slope.The results calculated by the proposed analysis method and the numerical simulation method fit each other well,which implies the validity of the proposed method.It can provide an efficient means not only for the seismic stability analysis,but also for the preliminary design of anchor-frame reinforced slope.