层状横观各向同性土中周期结构波阻板隔振效应理论解答

    Theoretical solution to the isolation effect of periodic structure wave impeding block in layered transverse isotropy soil

    • 摘要: 相较于传统波阻板(WIB),周期结构波阻板(PSWIB)具有带隙特性,可根据振源特性设计其组成参数实现对目标频率振动的隔离,然而既有研究忽略了PSWIB与周围土体的相互作用。为此,本文将 PSWIB 周围场地视为层状横观各向同性(TI)土体,基于声子晶体与等效介质理论,采用刚度矩阵法推导 PSWIB在层状TI场地的动力响应基本解,评估PSWIB在土体介质中的隔振性能。理论分析表明,与传统WIB相比,PSWIB 的隔振效率提高约 43.3%。周期层数与每层周期数等几何参数对隔振效果均表现出正向调控作用,而埋深的影响在<italic>t</italic>=0.8B时达到峰值,加速度幅值减小1.17m/ s2。此外,TI特性和波入射角度均显著影响场地动力响应,当Eh/Ev由 0.5 增至 2.0 时,位移峰值升高 17.5%,对应主导频率降低。

       

      Abstract: Periodic structure wave impeding block (PSWIB) has bandgap characteristics compared to traditional wave impeding block (WIB). The composition parameters of PSWIB can be designed based on the characteristics of the vibration source to achieve isolation of the target frequency vibration. However, existing research has overlooked the interaction between PSWIB and the surrounding soil. Therefore, this study considers the site around PSWIB as a layered transversely isotropic (TI) soil. Based on the theory of phononic crystals and equivalent media, the stiffness matrix method is used to derive the basic solution of the dynamic response of PSWIB in layered TI sites, and to evaluate the vibration isolation performance of PSWIB in soil media. Theoretical analysis shows that compared with traditional WIB, the isolation efficiency of PSWIB is improved by about 43.3%. The geometric parameters such as the number of cycles and the number of cycles per layer have a positive regulatory effect on the isolation effect, while the influence of burial depth reaches its peak at <italic>t</italic>=0.8<italic>B</italic>, and the acceleration amplitude decreases by 1.17m/s-2. In addition, TI characteristics and the incident angle of the wave significantly affect the dynamic response of the site. When <italic>Eh/Ev</italic> increases from 0.5 to 2.0, the peak displacement increases by 17.5%, corresponding to a decrease in dominant frequency.

       

    /

    返回文章
    返回