In this study, the dynamic response and damage mode of a pile-geogrid composite reinforced high-speed railway subgrade under seismic action were investigated based on a unidirectional shaking table test. Various seismic waves were applied to the subgrade, allowing for an analysis of acceleration, dynamic soil pressure, displacement, and strain responses. The displacement field of the subgrade was visualized using particle image velocimetry (PIV). The study shows that changes in peak ground acceleration (PGA) amplification factors become evident with height due to the presence of geogrid layers. The increase in peak ground motion causes a redistribution of dynamic soil pressures inside the subgrade. The transverse and longitudinal ribs of the geogrids provide an “anchoring effect”. The peak strain of the piles in the center is greater than that of the piles on the sides. The direction of soil particle displacement is closely related to the damage patterns observed in the subgrade. Damage begins to occur once the peak ground motion exceeds 0.4 g, characterized by collapse at the bottom of the subgrade.

中文翻译：

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地震作用下桩土工格栅复合加筋高速铁路路基动力响应及损伤


本研究基于单向振动台试验，研究了桩-土工格栅复合加筋高速铁路路基在地震作用下的动力响应和损伤模式。将各种地震波施加到路基上，以便分析加速度、动态土压力、位移和应变响应。使用粒子图像测速 (PIV) 可视化路基的位移场。研究表明，由于土工格栅层的存在，峰值地面加速度（PGA）放大系数的变化随着高度的增加而变得明显。峰值地面运动的增加导致路基内动态土压力的重新分布。土工格栅的横向和纵向肋提供“锚固效应”。中心桩的峰值应变大于两侧桩的峰值应变。土颗粒位移的方向与路基中观察到的损伤模式密切相关。一旦峰值地面运动超过 0.4 g，就会开始发生损坏，其特征是路基底部塌陷。