地震荷载下风积沙路堤动力响应规律

The study on dynamic responses of wind-blown sand subgrades under the earthquake load

为了研究风积沙路堤在地震动荷载下的动力响应规律,设计和制作了模型路堤并进行振动台试验,通过对模型中埋设的多个加速度传感器和位移传感器记录的数据进行分析,得出风积沙路堤模型在动荷载作用下的动力响应规律。得出如下结论:模型路堤对输入的地震波具有明显的放大作用,加速度反应放大系数PGA随着竖直高度的增加显著增大;在路堤内同一高度沿水平坐标的增大放大效应变化不明显或稍有增加;当控制地震波波形和强度相同时,边坡坡率越大PGA放大效应越明显;另外,风积沙路堤的阻尼比、自震频率、动模量等参数随着动荷载作用历史的变化而变化,从而进一步影响风积沙路堤加速度响应的频谱特性。研究风积沙路堤在动荷载作用下的动力响应,可以为沙漠地区高填方路堤抗震设计提供技术支持。

To study the seismic response of wind-blown sand embankment,built embankment model and desigend shaking table model test,according to analysis the data came from the several acceleration sensors and displacement sensors,acquired the dynamic responses regulation of wind-blown sand subgrades model,on the driven of dynamic load. The conclusion was that： The subgrades model has obvious amplification effect to input seismic waves,the PGA increased obviously with the increase of vertical height; At the same height in the model,the PGA has little increased with the increase of horizontal coordinate figure; When the seismic waveform and intensity ware determined,the amplification effect of PGA would be more obvious with the increased of slope rate; And,the damping ratios 、vibration frequencies and dynamical modulus of wind-blown sand embankment will change obviously with the times and intensity of shake in advance. The study on dynamic responses of wind-blown sand subgrades,can provide technical support to the anti-seismic of high fill embankment in the desert.