【摘要】 结合车辆-轨道耦合动力学及有限元谱分析技术,提出考虑扣件胶垫刚度频变特性的地铁隧道环境振动频域求解法。在理论与实测结果对比验证的基础上,探讨扣件胶垫刚度频变对地铁隧道环境振动频域分布特征的影响规律。结果表明:建立的地铁隧道环境振动频域求解法及其参数选取方法基本合理,并且在频域范围内有较好的预测精度;在地铁隧道环境振动中心频率25Hz以下,胶垫刚度频变的影响低于0.3dB,可不予考虑,但是频变的胶垫刚度会显著影响中心频率25Hz以上的近场地面高频振动响应,不仅影响其频域幅值大小,还将改变其频域分布;随着地铁轨道不平顺的持续恶化,如不考虑胶垫刚度的频变特性,仅提高胶垫刚度易导致地铁环境振动低频与高频预测结果出现顾此失彼的现象。更多还原

【Abstract】 By combining vehicle-track coupling dynamics with finite element spectral analysis methods,a frequency-domain algorithm of environment vibration induced by subway in tunnel was provided to allow for variation of stiffness of rail pad with frequency.Based on verification of the new algorithm by the measured data,the influence of frequency-dependent stiffness of rail pad on the frequency-distribution of environment vibration in subway tunnel was investigated.The conclusions showed that the proposed new frequency-domain approach for environment vibration due to subway in tunnel and the selection of the calculation parameters were basically reasonable and had high calculation accuracy in the frequency range.When the center frequency of subway tunnel environment vibration was below 25 Hz,the effect of frequency-dependent stiffness of rail pad was small.As it was less than 0.3dB,the effect can be neglected.However,the frequency-dependent stiffness of rail pad would have significant impact on near-field ground high frequency vibration response when the center frequency was above 25 Hz.In this case,the frequency-dependent stiffness of rail padwould not only influence the frequency-domain amplitudes,but also change its frequency-distribution.With continuous deterioration of subway track irregularity,simply increasing the constant stiffness of rail pad without considering frequency-dependent stiffness of rail pad would lead to errors in either the lower frequency domain or the higher one in environment vibration prediction results.更多还原