摘要
本文首次提出了地面连续和非连续屏障隔振的概念。指出非连续排桩屏障的散射效应决定隔振效果；而屏障的衍射效应决定其影响范围；同时对柔性屏障应避免其与人射波的“吻合效应”。通过理论与试验分析．证明圆形截面排极有较好的隔振效果。在工程上，突破了Woods等提出的桩径必须大于被屏蔽的波长的1／6结论（对于主要的地面波，桩径约需3～5m，这意味着在工程中无法实现），其屏蔽效果的主要影响因素是地基土的波长、屏障的深度和长度等。根据波的衍射理论和实测研究，在近场（主动隔振）屏障和远扬（被动隔振）屏障的设计深度方面，得出了与已有理论不同的结论。对屏障的面积率与波依的关系亦提出了定量计算公式，并应用于地面隔振工程设计。
This paper first puts forward the vibration isolation concept of continuous and discontinuous berriers in foundation soils. It points out that the scattering effect of discontinuous pile barrier de-termines the efficiency of vibration isolation, that the diffraction effect of barrier decides the range of vibration screening, and that the 'coincident effect' between flexible barriers and incident tyaves should be avoided. The analyses of test achievements and theoretical results show that the piles with circular section arranged in rows have fairly good efficiency of .vibration isolation. It breaks free from the design criterion raised by Woods, in which the incident wavelength LR has to be greater than six times the pile diameter d (which means that the pile needs to have a diameter of 3 ~ 5m, thus becoming practically impossible to be used in ordinary engineering), and the major factors affecting isolation effect are the wavelength in foundation soil, the depth and length of the barrier etc. In this paper, according to the study/of diffraction theory of waves and measurementsin fields, a conclusion different from the old theory has been obtained for designing depth of barrier in near field and far field vibration isolation. Considering the relationship between wavelength and the proportion of barrier area, the quantitative calculating formulae are presented, and have been applied in engineering practice.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
1997年第4期58-69,共12页
Journal of Building Structures
关键词
排桩
隔振
地面连续屏障
非连续屏障
piles in rows, vibration isolation, continuous barrier in foundation soils, discontinuous barrier
