以基于车辆-轨道耦合动力理论的地铁-钢弹簧浮置板耦合动力模型为基础,按照钢弹簧底座位置上力相互协调的原则,建立隧道-建筑物-地基二维有限元模型。然后从分析合建结构的自振特性和钢弹簧支反力的频谱特征入手,采用1/3倍频程振级评价法探讨不同固有频率钢弹簧浮置板轨道在不同合建结构形式中的适用性。研究结果表明:①地铁与建筑物合建结构的竖向自由振动20~80Hz的参振质量比例较高,可达50%以上,而4~10Hz竖向参振质量却差异较大,这与结构尺寸和刚度有关;②4~10Hz钢弹簧浮置板都可有效削减合建结构20~80Hz的竖向振动能量,但会放大浮置板固有频率附近的振动能量;③地铁低频振动传播容易在合建结构内引起共振,因此钢弹簧浮置板固有频率应避开合建结构4~10Hz内竖向参振质量较大且较集中的频段。
Using a coupling dynamic model of subway and steel-spring floating-slab track,based on the theory of vehicle-track coupling dynamics and in accordance with the basic principle that force is mutually coordinated on the base of steel spring,a 2-D finite element model of tunnel-building-foundation was established.For analysis of free vibration characteristics of the integrated structures and frequency spectrum characteristics of the steel-spring reaction force,the applicability of steel-spring floating-slab tracks of different natural frequencies for integrated metro-and-building structures was discussed according to the evaluation method of 1/3 octave vibration level.The results show: ①the mass of vertical free vibration in 20~80Hz generally occupies a high proportion of integrated structures of metro and building,more than 50%,however,in 4~10Hz the difference remains different;②the energy of vertical free vibration of the integrated structures in 20~80Hz can be reduced by steel-spring floating-slab tracks of natural frequencies 4~10Hz,but the vibration energy near the natural frequency of any steel-spring floating-slab track can be easily enlarged;③resonance can be easily aroused through the propagation of subway low-frequency vibration somewhere in some integrated structures,so the natural frequency of steel-spring floating-slab track should be,as much as possible,avoided to approach the frequency band in which the mass of the vertical free vibration of the integrated structures is larger and more concentrated within 4~10Hz.