重载列车振动荷载下交叉隧道动力响应分析

Dynamic Response of Crossing Tunnel under Heavy-heal Train Vibratory Load

结合某段交叉隧道的工程实例,采用三维有限差分软件对重载列车振动荷载下交叉隧道进行数值模拟,分析振动荷载对既有结构的动力响应影响规律.研究结果表明:既有结构最大沉降发生在交叉点处,且沉降趋势向两侧逐渐减小;道床受列车振动荷载影响最大,拱腰次之,拱顶最小;在重载列车振动荷载作用下,各监测点处的瞬时加速度均较大,在传播过程中加速度变化呈现正弦规律;列车运行时振动频率分布在0~20Hz范围内,表明重载列车通过时对交叉隧道引起低频高幅值振动.

Combined with the practical project of a railway cross tunnel,when a model has been built up with numerical simulation method under heavy heal train vibratory load, the influence of vibratory load on the existing construction was analyzed. The research results indicate that the maximum settlement occurs at the intersection of the existing construction, the rate of subsidence has been gradually reduced to both sides. The ballast bed is impacted most by the vibratory load of heavy heal trains, haunch is in the middle and vault is minimal. The transient acceleration of each observ- ing spot is high, the sine regularity of vibration occurs under spread process. The vibration fre- quency of the train is in the range from 0 to 20 Hz,which shows that the low frequency and high amplitude vibration is caused by heavy load train passing through the cross tunnel.