考虑地层横观各向同性的地铁临近环境减隔振超结构

Vibration-Reducing Metastructures in Subway Adjacent Environment Considering Transverse Isotropy of Soil

摘要:

基于能带理论的减隔振超结构由于其禁带特性而受到了广泛的关注，其中局域共振禁带对小尺寸结构实现低频减隔振具有重要意义，并被应用于地层土体表面波和体波减隔振。然而目前绝大多数研究集中于各向同性土体。考虑地层土体横观各向同性，研究二维橡胶-混凝土超结构对地铁振动的减隔振特性，对比分析了混凝土半径、橡胶厚度和土体各向异性对超结构全向禁带的影响。在此基础上建立不同方向透射和全尺寸透射模型，验证了弹性波在超结构禁带频率内能够有效衰减。探索了土体各向异性对减隔振超结构性能的影响，能够为地铁临近环境减隔振设计和分析提供参考及指导。

Abstract:

Vibration-reducing metastructures based on the periodic band structure theory have received extensive attention due to their bandgap characteristics. Among them， the locally resonant bandgap is of great significance for small-scale structures to achieve low-frequency vibration reduction and isolation， which has been applied to surface wave and body wave attenuation and isolation of ground soils. However， most of the current research focuses on isotropic soils. In this paper， considering the transverse isotropy of the ground soil， the vibration reduction and isolation characteristics of the two-dimensional rubber-concrete metastructures for subway vibration are studied. The effects of concrete radius， rubber thickness， and soil anisotropy on the omnidirectional bandgap of metastructures are comparatively discussed， based on which， the different directional transmission and full-scale transmission models are established. It is verified that the elastic waves can be effectively attenuated within the bandgap frequency of the metastructures. This paper explores the influence of soil anisotropy on the performance of vibration-reducing metastructures， which can provide reference and guidance for the design and analysis of vibration reduction and isolation in the vicinity of subways.