ZHANG Xi, LUO Wei-li, LIN Ben-hai, et al. Full-scale test and numerical investigation on vibration isolation effect of continuous and discontinuous barriers filled with ceramsite and sand[J]. 2022, 43(S1): 567-579.
DOI:
ZHANG Xi, LUO Wei-li, LIN Ben-hai, et al. Full-scale test and numerical investigation on vibration isolation effect of continuous and discontinuous barriers filled with ceramsite and sand[J]. 2022, 43(S1): 567-579.DOI: 10.16285/j.rsm.2021.0655.
Full-scale test and numerical investigation on vibration isolation effect of continuous and discontinuous barriers filled with ceramsite and sand
采用全尺试验方法,研究不同材料(陶粒、砂)填充不同类型屏障(连续型、非连续型)的隔振效果。同时,为弥补试验研究的不足,辅以数值研究。为此,在试验研究开展之前,在原场地上进行了面波多通道分析(multi channel analysis of surface waves,简称MASW)试验,以便获得场地的动力学特性,作为数值研究的基础。随后,开展试验工作以便获得场地固定点的传递函数与衰减分贝;并使用数值方法,编制程序计算加速度分量的空间分布场。综合以上两种方法后发现,隔振材料影响在低频处,两者差异不甚明显;在中频处,两者差异开始显现。陶粒的隔振表现接近空沟;在高频处,因土体的阻尼作用明显,材料影响难以表现。综上所述,陶粒的隔振效果远优于砂,整体表现接近空沟。屏障类型影响:当频率为30 Hz时,屏障的作用甚微,分量的空间分布形态以振源为圆心,呈环形分布;频率为50 Hz时,环形分布被屏障打破,其形态由环形变为椭圆形,而短边则指向波阵面方向,令一定强度的分量拒止于屏障的后区域;频率为80 Hz时,土体阻尼作用明显,以致两者差异不甚明显。综上,连续型屏障的隔振效果远优于非连续屏障。材料与屏障类型使用建议:若采用一般性的材料,考虑成本等因素,使用两者皆可;但采用高阻尼材料,考虑隔振效果等因素,则连续型屏障更优。
Abstract
In this paper
the full-scale test method is used to study the vibration isolation effect of different types of barriers (continuous and discontinuous) filled with different materials (ceramsite and sand). Meanwhile
to expand the experimental research
numerical research is supplemented. Therefore
to obtain the dynamic characteristics of the site as the basis of numerical research
the surface wave spectrum analysis (MASW) test was carried out on the original site before the experimental research. Then
to acquire the transfer function and attenuation decibels of the fixed point of the site by experimental research
the program is compiled to calculate the spatial distribution field of acceleration component through numerical method. After combining the above two methods
it is found that: Influence of vibration isolation material: at low frequency
the difference between them is not very obvious; at the intermediate frequency
the difference between the two begins to appear and the vibration isolation performance of ceramsite is close to that of open trench; at high frequency
the influence of material is difficult to show due to the obvious damping effect of soil. In conclusion
the vibration isolation effect of ceramsite is much better than that of sand
and the overall performance is close to the open trench. Influence of barrier type: when the frequency is 30 Hz
the barrier has little effect
and the spatial distribution of components takes the vibration source as the center
showing a circular distribution; When the frequency is 50 Hz
the annular distribution is broken by the barrier and its shape changes from annular to oval
while the short side points to the direction of the wave front
so that the component of a certain intensity is rejected in the rear area of the barrier; When the frequency is 80 Hz
the soil damping effect is obvious
so that the difference between them is not obvious. In conclusion
the vibration isolation effect of continuous barrier is much better than that of discontinuous barrier. Suggestions on the use of materials and barrier types: if general materials are used
both continuous and discontinuous barriers can be used considering factors such as cost. However
using high damping materials and considering the effect of vibration isolation