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基于动应力响应的路基振动碾压性能仿真分析
Numerical Analyses on Roller Compaction Performance of Subgrade Based on Dynamic Stress Response
【摘要】 为探究路基振动压实的动力响应特性,开展路基振动碾压的仿真分析,研究碾压过程中路基的竖向动应力响应分布规律,分析动应力沿路基深度及宽度方向的衰减效应,并探索压路机振动频率、名义振幅和碾压速度对路基内动应力分布的影响。结果表明:振动碾压下,路基内的竖向动应力近似呈长轴沿竖向的椭球状分布,振动能量主要沿深度方向传递,路基动应力随深度增加呈典型的指数函数规律衰减;振动频率28 Hz时产生共振现象,路基中竖向动应力达到最大值,说明此时土体吸收了更多的振动压实功,进而可达到更好的压实效果;随深度增加,路基中竖向动应力随名义振幅增加的增长速率逐渐减小,而其随碾压速度增大的衰减速率则有所增大。
【Abstract】 To investigate the dynamic response characteristics of subgrade under rolling compaction, numerical simulations on roller compaction of subgrade were performed for studying the distribution regularities of vertical dynamic stress of subgrade during the compaction process, analyzing the attenuation effect of dynamic stress along the depth and width directions of the subgrade, and exploring the influence of compactor vibration frequency, nominal amplitude, and compaction speed on the dynamic stress distribution of the subgrade. The results show that under roller compaction, the vertical dynamic stress of the subgrade presents an approximate ellipsoidal distribution pattern of which the long axis is in the vertical direction, indicating that the vibration energy mainly transmits along the depth direction. The dynamic stress of the subgrade displays a distinct exponential attenuation relationship with increasing the depth. Resonance phenomenon occurred at a vibration frequency of 28 Hz, under which the vertical dynamic stress in the subgrade reached its maximum value, suggesting that the subgrade soil absorbed more vibration compaction energy at this condition and could therefore achieve better compaction effect. Moreover, with increasing the depth, the growth rate of the vertical dynamic stress in the subgrade gradually decreased as the nominal amplitude increased, while its attenuation rate gradually increased with the increase of the compaction speed.
【Key words】 subgrade; roller compaction; dynamic stress; distribution regularity; compaction parameter; numerical simulation;
- 【文献出处】 铁道建筑 ,Railway Engineering , 编辑部邮箱 ,2024年05期
- 【分类号】U213.1
- 【下载频次】19