紧邻铁路暗挖地铁隧道动力响应实测与数值分析

Measurement and numerical analysis on dynamic response of underground subway tunnel adjacent to railway

铁路下伏隧道时,其动力响应异于无隧道的情况。以深圳地铁5号线紧邻平南铁路深民区间隧道为依托,采用加速度传感器对列车荷载在隧道初支上引起的加速度进行测试,并通过弹塑性动力有限差分法对列车荷载与隧道组成的系统进行动力响应分析。研究结果表明:列车速度为40～60 km/h,紧邻铁路隧道拱肩振动加速度峰值为0.06～0.10 m/s2,较地表路肩处竖向加速度峰值衰减90%～96%;对比有无下伏隧道工况,下伏隧道使列车荷载在表层土中激发的振动减小,而在隧道周边围岩中的振动增大,延缓列车动载在地层中衰减;隧道初支内力受列车动载影响,弯矩约增大1.4%。

The dynamic response of railway above tunnel is different from the non tunnel the Shenmin tunnel of Shenzhen Metro Line No. 5 adjacent to Ping Nan railway for the bac circumstance. Taking kground, the acceler ation caused by train loads on primary lining was collected with acceleration sensor. Based on the elastic plastic dynamic finite difference method, the system composed by train loads and tunnel was adopted to analyze the dy namic response. The results indicate that when the train speed is 40 60 km/h, spandrel vibration acceleration of subway tunnel ,nearing railway area, reaches the peak is 0.06 0.10 m/s2, and compared to road shoulder, the vertical acceleration peak value is reduced by 90% 96%. The underlying tunnel causes the decline of the topsoil vibration excited by train loads, the increase of the wall rock vibration excited by train loads, and the train dynamic load is impeded greatly in the stratum. The internal force of initial tunnel is affected by the train dynamic load,which the bending moment is increased by 1.4% approximately.