城市轨道交通浮置式减振措施的减振降噪效果

从分析轨道交通地下隧道振动传播特征出发,说明了地下振动的传播规律,并给出了不同埋深条件下地下振动影响范围的经验公式;结合地下振动激发频率特征的分析,对减振措施的减振效果的合理评价量进行了分析,指出采用Z计权减振效果评价量将获得与实际应用效果一致的降噪效果。结合两种浮置式减振措施减振降噪效果的实测,指出浮置板道床的减振效果应采用安装减振垫浮置板道床前后桥面的Z振级差来评价,而不宜采用轨面与桥梁直接的振级落差来评价。对橡胶减振垫以及钢弹簧浮置板的实测减振降噪效果进行了介绍。

NOISE AND VIBRATION REDUCTION EFFICIENCY OF FLOAT DAMPING IN URBAN RAIL SYSTEM

Starting from propagation of vibration radiated from underground tunnels,the propagation characteristics of underground vibration was explained,and empirical formula for calculating critical distance of vibration decay was proposed.With the help of spectrum analysis of underground vibration,rational evaluation metric of vibration reduction for damping structures was discussed,and it was pointed out that the Z weighted vibration reduction metric was in better agreement with actual measured results from subways lines of several domestic cities.From noise and vibration reduction test of two typical floating damping structures,it was stressed that the Z-weighted vibration level difference on the bridges before and after the installation of damping measures should be used as the metric of vibration reduction,rather than the vibration difference between the rail and bridge.The actual measured noise and vibration reduction efficiency of rubber damper and spring damper were introuduced.