地下动荷载作用下非饱和土地基中双层波阻板隔振性能研究  

STUDY ON THE VIBRATION ISOLATION PERFORMANCE OF DOUBLELAYER WAVE IMPEDING BLOCK IN UNSATURATED SOIL FOUNDATION UNDER UNDERGROUND DYNAMIC LOADING

作　　者：张猛 马强 ZHANG Meng;MA Qiang(School of Civil Engineering,Qinghai University,Xining 810016,China;Qinghai Provincial Key Laboratory of Energy-Saving Building Materials and Engineering Safety,Xining 810016,China)

机构地区：[1]青海大学土木工程学院,西宁810016 [2]青海省建筑节能材料与工程安全重点实验室,西宁810016

出　　处：《工程力学》2024年第10期64-79,共16页Engineering Mechanics

基　　金：国家自然科学基金项目(52168053);青海省自然科学基金青年基金项目(2021-ZJ-943Q)。

摘　　要：为了探究非饱和土地基中波阻板的隔振性能以及提升传统均质波阻板隔振的频宽。基于单相弹性介质理论和非饱和多孔介质理论,对地下动荷载作用下非饱和土地基中双层波阻板的隔振效果进行了研究。利用Fourier积分变换和Helmholtz矢量分解原理,建立了地下动荷载作用下非饱和土地基动力响应的计算列式。分析了双层波阻板各层弹性模量、密度、板厚、埋深、土体饱和度及荷载频率等物理力学参数对双层波阻板隔振性能的影响规律。研究结果表明:通过设计波阻板各层的弹性模量和密度可获得双层波阻板的最佳隔振效果,同等厚度下,双层波阻板的隔振效果要优于均质波阻板。双层波阻板提升了均质波阻板减振的频宽,其对低中高频振动(5 Hz≤f≤80 Hz)均有良好的隔振效果。双层波阻板的埋深越靠近振源处隔振效果越好,并且存在临界厚度,当波阻板厚度超过其临界厚度时,隔振效果随厚度的增大而减小。土体饱和度对双层波阻板隔振效果影响显著,在低饱和度时双层波阻板可以取得更好的隔振效果。In order to investigate the vibration isolation performance of a wave impeding block(WIB)in unsaturated soil foundation and to improve the frequency width of vibration isolation of conventional homogeneous WIBs,the vibration isolation effect of double-layer WIBs in unsaturated soil foundation under an underground dynamic load is studied upon the theory of single-phase elastic and unsaturated porous medium.Using the Fourier transform and Helmholtz vector decomposition,one calculation formula of the dynamic response of unsaturated soil foundation under underground dynamic loading is established.Analyzed for the influence of physical and mechanical parameters are elastic modulus,density,thickness,embedded depth,load frequency and soil saturation on the vibration isolation performance of the double-layer WIB.The results show that the best vibration isolation effect of double-layer WIBs can be obtained by designing the elastic modulus and density of each layer of WIBs.At the same thickness,the vibration isolation effect of the double-layer WIB is better than that of the homogeneous WIB.The double-layer WIB enhances the frequency width of homogeneous WIB vibration damping,which has a better vibration isolation effect on low,medium and high-frequency vibration(5 Hz≤f≤80 Hz).When the thickness of double-layer WIB exceeds the critical thickness,the vibration isolation effect decreases with the increase of thickness.Soil saturation has a significant effect on the vibration isolation effect of the double-layer WIB,and the double-layer WIB can achieve a better vibration isolation effect at a low saturation.

关 键 词：地下动荷载 非饱和土地基 双层波阻板 弹性模量 隔振设计 

分 类 号：TU435[建筑科学—岩土工程]