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列车运行速度的提高会加剧轨道路基结构的振动,削弱其动力稳定性,并可能产生过大的附加沉降,严重时可导致轨道路基结构失稳破坏,因此,在列车荷载作用下高铁路基结构的动力响应是世界各国高速铁路建设及运营过程中亟待解决的课题。依托典型高速铁路路基工程,利用自主研制的伺服激振控制系统,开展了大比例尺的高铁路基激振模型试验研究,通过激振器模拟列车轮轴循环加载,得到了不同频率激振力作用下路基不同层位的速度的时程变化曲线及幅值空间分布特征;揭示了列车荷载作用下路基速度幅值传递及衰减规律。研究表明,不同频率的激振力作用下路基土体的速度曲线具有明显的周期性峰值;同一频率作用下路基土体中速度幅值沿深度方向不断减小,呈指数衰减趋势,随着深度的增加。研究成果为相应实际工程的设计、施工及运营提供了一定的参考及借鉴。
The increase of train running speed will aggravate the vibration of track subgrade structure, weaken its dynamic stability and may cause excessive additional settlement, which may lead to the instability of subgrade structure. In the case of train load, Dynamic response is the urgent issue to be solved in the construction and operation of high-speed railway in various countries of the world. Relying on the typical high-speed railway subgrade project, a large-scale experimental study of high-speed railway subgrade excitation model was carried out by using self-developed servo excitation control system. The vibration load of the train axle was simulated by exciter to obtain the subgrade The temporal variation curves and the spatial distribution characteristics of the velocities of different layers are revealed, and the law of amplitude transmission and attenuation of the subgrade under the train loads is revealed. The results show that the velocity curves of subgrade soils have obvious periodic peaks under the excitation force of different frequencies. The amplitude of subgrade soils under the same frequency continuously decreases along the depth direction and declines exponentially with depth Increase. The research results provide some reference and reference for the design, construction and operation of the corresponding actual project.