连接螺栓对盾构隧道振动响应的影响分析

Analysis of the Impact of Connecting Bolts on the Vibration Response of Shield Tunnels

为了研究螺栓失效对盾构隧道振动响应的影响,并探明螺栓失效时衬砌的作用,以国内某盾构隧道为工程背景,建立三维精细化数值计算模型,采用显示动力时程法对隧道的动力响应进行计算分析。结果表明:(1)在列车振动荷载作用下,管片螺栓失效导致隧道内部结构的峰值加速度增加39.5%,管片的峰值加速度增加64.8%,表明螺栓失效降低了隧道衬砌结构的刚度,从而导致隧道结构的动力响应更加剧烈。(2)在螺栓失效时,双层衬砌隧道的内部结构峰值加速度比单层衬砌隧道的峰值加速度低13.3%,且前者的管片峰值加速度比后者的管片峰值加速度低54.1%,表明双层衬砌盾构隧道在列车振动荷载下的动力响应更弱,即二次衬砌能缓冲列车行进对隧道结构的冲击力。(3)在列车荷载作用下,管片的峰值加速度最大为内部结构峰值加速度的17.2%,列车荷载主要由内部结构承担。(4)螺栓失效对管片与内部结构连接位置的峰值应力和位移几乎没有影响,表明列车荷载作用下连接位置的应力与位移对于螺栓失效并不敏感。(5)二次衬砌的施作使管片与内部结构连接位置的峰值加速度降低了57.0%,位移降低了22.2%,最大主应力降低了21.4%,表明二次衬砌能够降低管片与内部结构连接位置在列车荷载作用下的动力响应,保护隧道结构。

To study the impact of bolt failure on the dynamic response of a shield tunnel to train loads and to clarify the action of linings under bolt failure,a three-dimensional refined numerical model was established based on a do⁃mestic shield tunnel project.The explicit dynamic time-history method was used to calculate and analyze the tunnel's dynamic response.The results show that:(1)Under train vibration load,the failure of segment bolts increases the peak acceleration of the tunnel's internal structure by 29.4%and the segment peak acceleration by 64.8%,indicating that bolt failure reduces the stiffness of the tunnel lining structure,thereby exacerbating the tunnel structure's dy⁃namic response.(2)When bolts fail,the peak acceleration of the internal structure of a double-layer lining tunnel is 13.3%lower than that of a single-layer lining tunnel,and the peak acceleration of the segments is 54.1%lower,in⁃dicating that the double-layer lining shield tunnel has a weaker dynamic response under train vibration load.This shows that secondary lining can buffer the impact force of trains on the tunnel structure.(3)Under train load,the maximum peak acceleration of segments is 17.2%of the peak acceleration of the internal structure,indicating that the train load is mainly borne by the internal structure.(4)Bolt failure has almost no impact on the peak stress and displacement at the connection between segments and the internal structure,suggesting that stress and displacement at the connection point under train load are not sensitive to bolt failure.(5)The application of secondary lining re⁃duces the peak acceleration at the connection between segments and the internal structure by 57.1%,displacement by 22.2%,and maximum principal stress by 21.4%,indicating that secondary lining can reduce the dynamic re⁃sponse at the connection under train load,protecting the tunnel structure.