减振层对地铁移动荷载下环境振动影响研究

Study on the Effect of Damping Layer on the Environmental Vibration of Subway Under Moving Load

针对日益密集的轨道交通网络引发的环境振动问题,目前减振措施以轨道减振为主,而传播途径上的减振措施,因施工条件制约,其应用受到局限。由于设置减震层能有效减小隧道动力响应,故文章从结构减振的角度,探讨'围岩-初衬-减振层-二衬'的减振模式,基于荷载-结构法原理,探究泡沫混凝土、沥青、橡胶3种减振材料作为减振层的减振效果。结果表明:加设减振层能有效减小隧道衬砌结构、地层、地面的振动响应,使地面Z振级符合标准限值,泡沫混凝土层对地面振动放大效应衰减幅度最大,达9.5%,对30~80Hz频段的减振效果最明显,在实际工程中可以考虑加设泡沫混凝土层作为有效减振措施。

Aiming at the problem of environmental vibration caused by the increasingly dense rail transit network,the vibration reduction measures give priority to track vibration reduction currently,due to the constraints of construction conditions,the damping effect of current damping measures in the process of transmission is limited.Because setting damping layer can effectively reduce the dynamic response of tunnel,in terms of structural vibration reduction,this paper introduces the vibration reduction model of 'surrounding rock-initial Lining-damping layer-two lining',using simulation technology of 'load-structure',exploring the effect of three kinds of damping layer:foam concrete,asphalt and rubber.The results show that:damping layer can effectively reduce the vibration response of tunnel lining structure,stratum and ground,which make Z vibration level of ground accord with thestandardlimit.Inparticular,the foam concrete layer gets the maximum attenuation amplitude of ground vibration amplification effect,up to 9.5%,and which makes damping effect of 30~80Hz band most obvious.So the foam concrete layer can be used as an effective vibration reduction measures in the actual projects.