隧道内支承块空吊对钢轨竖向位移影响

为研究隧道内列车荷载下弹性支承块空吊对钢轨竖向位移的影响,基于银洞坡和定水坝隧道现场实测数据,建立考虑支承块空吊的力学模型,分析连续1~3块支承块空吊情况下钢轨竖向位移的超限情况。实测和研究结果表明:隧道内实测的空吊位置和量值具有不确定性特征,空吊现象引起的钢轨竖向位移有超过安全指标的情况;单块支承块空吊值在10 mm以下,钢轨竖向位移不出现超限情况,当连续2块或连续3块支承块空吊量大于3 mm时,钢轨竖向位移出现超限情况,对于隧道内复杂的支承块空吊病害,建议控制空吊量在3 mm以内,同时应尽量避免连续空吊情况。

The Effect of Suspended Bearing Block inside Tunnel on Rail Vertical Displacement

In order to understand the effect of the suspended bearing block in tunnel on rail vertical displacement due to train load inside the tunnel,the mechanical model for suspended bearing block is established based on measured data from Yindongpo tunnel and Dingshuiba tunnel to analyze the vertical displacement over limit of the rail with 1 to 3 bearing blocks suspended continuously. The results show that the positions and values of suspended bearing blocks are uncertain inside the tunnel and the rail vertical displacement caused by suspended bearing block exceeds the limit; when the suspension of only one position is less than 10 mm,the limit of vertical displacement of the rail is not exceeded,when the values of two or three consecutive positions are more than 3mm,the limit of vertical displacement of the rail is exceeded. Thus,the paper recommends that the value of bearing block suspension is controlled within 3 mm in the complex tunnel condition,and consecutive bearing block suspension should be avoided as much as possible.