高速铁路路基压实过程中的空间动力响应

Spatial Dynamic Response Characteristics of High Speed Railway Subgrade During Compaction

依托京雄(北京—雄安)高速铁路路基工程,采用现场试验和数值模拟相结合的方法,分析了压路机振动荷载作用下高速铁路路基动力响应特性与演化规律。结果表明:压实过程中沿振动轮宽度方向轮缘下方土体竖向压应力较大,而振动轮中间部位竖向压应力较小且分布较为均匀;土体竖向加速度、速度沿深度方向或水平方向的衰减规律大致相似,竖向加速度的衰减呈现更明显的规律性;压路机激振力频率、激振力幅值、速度和土体弹性模量在不同参数水平下衰减规律相似,但衰减速度与影响深度不同。

Based on the subgrade project of Beijing-Xiong’an high speed railway,the dynamic response characteristics and evolution laws of high speed railway subgrade under roller vibration load were analyzed by means of field test and numerical simulation. The results show that the vertical compressive stress of the soil under the rim of the vibrating wheel is larger along the width direction of the vibrating wheel,while the vertical compressive stress in the middle of the vibrating wheel is smaller and more evenly distributed. The attenuation laws of vertical acceleration and velocity along the depth direction or horizontal direction are roughly similar,and the attenuation of vertical acceleration has more obvious regularity. The attenuation laws of various indexes(excitation force frequency,excitation force amplitude,driving speed)of the roller and the elastic modulus of soil mass are similar at different parameter levels,but the attenuation speed and influence depth are different.