论文部分内容阅读
边坡地震动放大效应的研究是开展边坡抗震设计的基础。提出基于白噪声的地震动荷载反演方法,通过动力学计算和频谱分析发现边坡具有宽频带反应体系的特性,单面均质边坡在坡肩处的放大系数最大且通常不超过2.0。较之于考虑行波效应的地震动输入方式,采用时空一致地震动输入的计算结果偏保守。地震波频谱特性对放大系数影响的研究表明,抗震设计中应依据边坡所在场地的设计地震分组确定放大系数。通过引入一个与周期同量纲的参量来综合反映坡高、坡度和岩体波速对坡肩放大系数的影响,并针对Taft波和El Centro波分别计算获得了坡肩水平向放大系数的谱曲线。放大系数的包络分析表明边坡表面的放大系数通常不超过1.85。研究结果可为均质岩体边坡的抗震设计提供理论依据与技术支持。
The research on the magnifying effect of slope ground motion is the basis for seismic design of slope. Based on white noise, a dynamic seismic load inversion method is proposed. The results show that the slope has the characteristics of wideband reaction system through dynamic calculation and spectral analysis. The maximum magnification factor of single-sided homogeneous slope at the shoulder is the maximum and usually does not exceed 2.0. Comparing with the input method of ground motion considering the traveling wave effect, the result of using the spatiotemporal ground motion input is conservative. The research on the influence of seismic wave spectrum characteristics on the amplification factor shows that the magnification factor should be determined according to the design seismic group of the site where the slope is located in the seismic design. The influence of slope height, slope and rock mass velocity on the magnification of slope shoulder is comprehensively reflected by introducing a parameter of the same dimension with period. The spectral curve of horizontal magnification coefficient of slope shoulder is calculated by Taft wave and El Centro wave respectively . Envelope analysis of the magnification factor shows that the magnification factor of the slope surface does not usually exceed 1.85. The results can provide theoretical basis and technical support for seismic design of homogeneous rock slopes.