地铁环境振动预测中链式结构振级落差灵敏度分析

针对地铁环境振动预测中使用的链式结构力学简化模型,利用灵敏度分析对链式结构中各参数变化对各振级落差影响规律进行系统研究;推导给出振级落差一阶灵敏度解析表达式和一种逆矩阵偏导数求解方法;并提出利用自由衰减时域段实测数据逆求链式结构中各力学参数方法。研究结果表明:通过灵敏度分析可以确定链式结构中任一力学参数改变对其任一层振级落差影响程度,找出对系统动态响应影响较大的环节。该方法有助于提高环境振动预测精度。

Sensitivity Analysis on Vibration Level Difference of Chain Structure in Metro-induced Environmental Vibration Prediction

By the simplified chain structure model used in metro-induced environmental vibration prediction,systematic study on the law of the impacts of parameter changes in any layer of the chain structure on the vibration level differences of all layers was carried out with the sensitivity analysis method.The analytical expression of first-order sensitivity of the vibration level difference was deduced.The simple and practical method was proposed to resolve mechanical parameters with the data measured in the free attenuation time domain.The study results show that we can find the layer which cannot be ignored in respect of coupling and attributes so as to raise the environmental vibration prediction accuracy.