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基于弹性波动理论,概化刚性挡土墙的动力分析模型,利用水平分层法,建立单元体的受力平衡微分方程,借助Hilbert-Huang变换,提出地震作用下刚性挡土墙地震主动土压力的时频域计算方法,并通过与振动台试验结果的对比验证该方法的合理性。分析输入波频率对刚性挡土墙墙后填土的临界破裂角、地震主动土压力合力以及作用点的影响,结果表明:随着地震烈度的增大,临界破裂角逐渐减小,地震主动土压力合力逐渐增大,合力作用点位置略有上移;随着输入波频率的增大,临界破裂角和地震主动土压力合力分别呈“倒马鞍型”和“正马鞍形”分布,并且均在输入波频率与刚性挡土墙系统自振频率相近时达到最大,而地震主动土压力合力的作用点则基本上不变;按照现有规范不考虑输入波频率进行刚性挡土墙地震稳定性设计,可能会降低挡墙的地震安全储备。刚性挡土墙地震主动土压力的时频域计算方法不仅能够考虑地震波三要素(峰值、频率以及持时)对挡墙土压力的影响,同时也能够为其他类型支挡结构的抗震时频设计提供一定的参考。
Based on the theory of elastic wave, the dynamic analysis model of rigid retaining wall is generalized. By means of horizontal stratification method, the force balance differential equation of element body is established. By means of Hilbert-Huang transform, the active earth pressure of rigid retaining wall under earthquake Time-frequency calculation method, and compared with the shaking table test results to verify the rationality of the method. The effect of input wave frequency on the critical cracking angle of backfilled soil, active earth pressure resultant force and action point of rigid retaining wall is analyzed. The results show that the critical crack angle decreases with the increase of earthquake intensity, With the increase of input wave frequency, the critical breaking angle and the earthquakes active earth pressure resultant force showed “saddle saddle” and “positive saddle saddle”, respectively. And reach the maximum when the input wave frequency is close to the natural frequency of the rigid retaining wall system, while the active points of seismic active earth pressure are basically unchanged. In accordance with the existing specifications, the rigid retaining earth Wall seismic stability design may reduce the seismic safety reserve of retaining wall. The time-frequency calculation method for seismic active earth pressure of rigid retaining wall can not only consider the influence of seismic wave three elements (peak, frequency and duration) on the earth pressure on the retaining wall, but also can be used in seismic time-frequency design of other types of retaining structures Provide some reference