近接隧道列车运行时地表振动响应数值模拟

鉴于目前城市地下铁路隧道平行、交叠的情况逐年增加，且对多列车耦合荷载作用下地表振动规律尚不清楚，本文建立了大直径盾构隧道下穿双线地铁隧道三维数值分析模型，并通过现有运行列车参数建立了刚体列车模型以及实体轨道模型。采用Hertz接触模拟了运动列车轮与钢轨的接触，通过罚接触与硬接触模拟了隧道与围岩的非线性接触，利用无限元人工边界模拟了无限半空间。使用时域显式整体分析方法模拟了编组列车在隧道内的运行并与实测地表振动加速度结果进行了对比，结果表明本文建立的数值模型能够较好地反映出真实地铁列车运行时地表的振动响应。在此基础上，分析了多线隧道交汇段不同列车运行工况下地表竖向加速度的时频特性以及分布规律。

Numerical Study on Ground Surface Vibration Response Under Train Load in Multi Adjacent Tunnels

In view of the increasing number of parallel and overlapping cases of underground tunnels and the unknown ground vibration law under the coupled load of subway and high-speed railway trains, the authors established a three-dimensional numerical analysis model of a large diameter shield tunnel under passing a double-line subway tunnel, and brought in a rigid train model and a track model based on the existing operating train parameters. The Hertz contact was used to simulate the contact between a moving train wheelset and a rail, the nonlinear contact between tunnel and surrounding rock was simulated by penalty contact and hard contact, and the infinite half space was simulated by using an infinite artificial boundary. By using the time domain explicit global analysis method, the operation of the running train in the tunnel was simulated and compared with the measured ground acceleration results, and the time-frequency characteristics of the vertical acceleration under the operation of single-line subway train and single-line high-speed train, as well as the distribution law of the surface acceleration under complex operating conditions were analyzed. The results show that the numerical model established in this study can better reflect the vibration response of the ground when the subway train is running.