近距离空间交叉盾构隧道列车振动响应特性研究

针对目前国内近距离空间交叉盾构隧道工程,采用拟合的列车振动荷载公式,考虑列车的行驶效应,通过在轮轴对上施加振动力时程曲线,同时给予轮轴一定的行驶速度来研究列车振动作用下空间交叉盾构隧道的动力特性。在特定列车行驶速度和围岩条件下,交叉位置对应上下隧道截面的应力和加速度情况进行分析,并对上下交叉隧道纵向不同位置的加速度时程响应进行研究。获得上部和下部隧道交叉截面第一主应力和加速度分布形态及其相对不同交叉净距的变化趋势,揭示了列车在隧道内行驶时,特定观测点出现明显动力响应存在一个对应的影响区,对比下部隧道交叉处(纵向中截面)位置点的加速度响应值与其左右各点相应加速度在数值大小和一阶频率上的区别。研究所得结论对高速铁路空间交叉盾构隧道的设计具有一定的参考价值。

The Characteristic Analysis of Short Distance Space Geometry Shield Tunnel under Train Vibration

This paper aims at solving the current problem of short distance space geometry shield tunnel engineering in China by using the fitting train vibration load formula and applying vibration force time history curves and velocity to the wheel axles to simulate the effect of running train and analyze the dynamic characteristics of space geometry structures. This paper analyzes major principal stress and acceleration envelope curve of the cross position at a specific train speed and level of surrounding rock,and studies the response of acceleration time history at different locations of the upper and lower parts of the tunnel. The present study focuses on the distribution of the first main stress and acceleration and the trend of changes in different distances. The results conclude that when a train running in the tunnel,there is a train influencing area corresponding to the dynamic response of observation points,and difference exists between the intersection of lower tunnel and other observation points in acceleration response value and first frequency. The conclusion may serve as a reference for the space geometry shield tunnel construction of high-speed railway.