【摘要】 在已完成的振动台模型试验基础上,进一步采用数值模拟方法定量研究含软弱夹层锚框支护边坡的地震动态响应规律.坡面与坡内各测点处的水平加速度峰值(PHA)放大系数均随高程增加而非线性增大,表现出明显的鞭梢效应;但软弱夹层的存在改变了其附近测点高程效应表现形式,并在大振幅工况下表现出明显的隔震效应.小振幅工况下,各测点处的正负向水平土压力峰值(PEP)震荡系数都大致相等;随着地震动幅值增大,最小动土压力逐渐趋于为零(几乎脱空);而最大动土压力可高达静止土压力的4～7倍.高频成分丰富的WC波,其卓越频率与边坡自振频率较接近,故其引起加速度与土压力动态响应,均明显大于其他类型地震波.以上数值模拟所反映的含软弱夹层锚框支护边坡地震动态响应规律,与振动台模型试验结果大致吻合.但从量值上看,数值模拟中PHA放大系数(坡顶部位)和PEP震荡系数(正向)均明显大于模型试验结果,认为模型试验中相似材料超强设计、测点布设过少等缺点,应在进一步研究中予以克服.更多还原

【Abstract】 Base on the shaking table model tests,the numerical simulations are further carried out to quantitatively study the seismic responses of weak interlayered slope with anchor-frame reinforcement.The amplification coefficient of peak horizontal acceleration increases nonlinearly 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 under the scenario of large amplitude excitation.The positive and negative oscillation coefficients of peak earth pressure are basically equaled under small amplitude excitation.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.The WC wave is abundant with high-frequency component,whose predominant frequency is close to the natural frequency of slope.Therefore,the responses of slope acceleration and earth pressure under the excitation of WC wave are greater than other waves.The aforementioned seismic responses reflected by numerical simulations agree with the shaking table model tests in generally.In quantitatively,however,the amplification coefficient of peak horizontal acceleration at the top of slope and the positive oscillation coefficients of peak earth pressure are significantly greater than their counterparts from shaking table model tests.The shortcomings in shaking table tests,such as extra-strong design of similar material and the lack of instrumentation,should be improved in the further studies.更多还原