盾构隧道基底软硬过渡地段列车振动响应分析

Analysis of Train Vibratory Response of Shield Tunnels in Complex Uneven Soft-hard Strata Transition Sections

论述了隧道衬砌结构-围岩系统动力分析的理论和数值计算方法,采用激振力函数模拟高速列车竖向振动荷载,考虑隧道基底地层纵向软硬不均,建立了广深港客运专线狮子洋盾构隧道列车振动响应三维有限差分计算模型,研究了高速列车振动荷载作用下软硬不均过渡地段隧道衬砌结构振动响应规律,并通过引入长期列车振动荷载作用下地基土累积变形计算模型,预测了软硬不均地层条件下不同地段隧道基底的长期差异沉降.计算结果对评价软硬不均地层盾构隧道衬砌结构的动力稳定性和控制隧道基底不均匀沉降具有一定的指导意义.

A theory of dynam ic FDM and a numericalmethod for the lining structure of tunnels and surround-ing rock systems are put forward.Based on the numerical simulation of vertical load induced by high speed train with excitation function,a three-d imension finite d ifference model that takes into account the longitud i-nal uneven tunnel basement strata of Shi Z iyang shield tunnel is established to study structure dynam ic me-chanical response.The dynam ic response characteristics of tunnel structure by the high-speed train vibration load is stud ied and the research emphasizes the variation of tunnel lining structure d isplacement and principal stress under the longitud inal uneven strata cond itions.The d ifferent long-term settlement under uneven tun-nel basement strata is pred icted by introducing the empirical accumulative plastic strain model.The analysis results have significance not only for the dynam ic stability evaluation of tunnel structures for high-speed rail-way but also for the control of uneven settlement.