钢弹簧浮置板浸水条件下的减振效果

Vibration Reduction Effect of Steel Spring Floating Slabs under Water Immersion Conditions

[目的]针对浮置板浸水后的减振效果问题,有必要研究运营条件下列车运行速度、钢弹簧隔振器刚度对减振效果的影响。[方法]基于流固耦合理论,建立了包含浸水钢弹簧浮置板与隧道在内的浮置板-浸水-隧道流固耦合振动模型,通过实测数据验证了所提模型的准确性;分析浸水浮置板在列车荷载作用下,隔振器刚度和列车运行速度对其减振效果的影响。[结果及结论]钢弹簧浮置板浸水工况下,隔振器刚度和列车运行速度的变化主要影响隧道壁振动级的幅值,对主频分布影响较小。当钢弹簧隔振器刚度越大或列车运行速度越高时,浮置板在发生浸水时的减振效果降低越明显。当浸水深度从80 mm增加至160 mm以上(即浸水达到浮置板板侧空间高度的1/4~1/2)时,隧道壁最大Z振级幅值会增大10%以上。在浸水浮置板工况下,列车运行速度从80 km/h降低至40 km/h时,隧道壁振动级最大降低约8%,但仍大于无浸水工况时的隧道壁振动级。当浸水高度超过板侧空间高度1/2以上时,无论是降低隔振器刚度或降低列车运行速度,均对减振效果的提升作用有限。

[Objective]To address the issues of reduced vibration isolation performance of floating slabs under water immersion,it is necessary to study the impact of train operating speed and steel spring isolator stiffness on vibration reduction under operational conditions.[Method]Based on fluid-structure interaction theory,a floating slab-immersion-tunnel fluid structure coupled vibration model is developed,incorporating the water-immersed steel spring floating slab and the tunnel.The accuracy of the model is validated using field data.The isolator stiffness and train speed affecting the vibration reduction performance of the water-immersed floating slab under train load action is analyzed.[Result&Conclusion]Under steel spring floating slab water immersion conditions,changes in isolator stiffness and train operating speed primarily affect the amplitude of tunnel wall vibration,with minimal impact on the distribution of the dominant frequencies.As the stiffness of the steel spring isolators increases or the train operating speed rises,the vibration reduction performance of the floating slab deteriorates more significantly when immersed.When the water depth increases from 80 mm to over 160 mm(the immersion reaches from 1/4 to 1/2 of the slab side space height),the maximum Z-vibration level of the tunnel wall increases by over 10%.When the train operating speed decreases from 80 km/h to 40 km/h under floating slab water immersion conditions,the maximum vibration level of the tunnel wall decreases by approximately 8%,though it remains higher than that under non-immersed conditions.Once the water height exceeds 1/2 of the slab side space height,further reducing isolator stiffness or train operating speed is limited in improving vibration reduction performance.