摘要
横向地震动激励下,渡槽中水体发生晃动,有可能放大渡槽的地震响应。为抑制渡槽中的水体振动,该文提出了适用于大型渡槽的导水屏障。该导水屏障沿顺槽向安装于渡槽中,将水体横向分隔,同时设置了部分通孔,便于水体通过,由此改变水体在渡槽中的横向振动特征,进而减小渡槽地震响应。为探究导水屏障对渡槽的减震效果,依托典型的大型渡槽实际工程,该文设计了矩形渡槽和U形渡槽的振动台试验,考虑了槽内水位高度、屏障透水率等参数对渡槽减震效果的影响。通过振动台试验,获得了渡槽在白噪声、简谐荷载和地震动激励下的动力响应,同时得到了渡槽的自振频率和盖梁峰值加速度等结构响应。试验结果表明:导水屏障可以提升渡槽溢水的台面加速度阈值,实际减小了渡槽中水体振动。定义渡槽盖梁峰值加速度之比为减震系数,减震系数与渡槽断面类型、槽内水位、激振频率和导水屏障透水率等均相关。当激振频率接近渡槽基频时,导水屏障呈现良好的减震效果;当激振频率远离渡槽基频时,导水屏障反而可能导致渡槽地震响应放大。在El centro地震动激励下,大部分工况中导水屏障呈现良好的减震效果,减震系数的均值和标准差受槽内水位、导水屏障透水率等因素影响较大,导水屏障的定量减震机理还有待进一步研究。
[Objective]Under transverse earthquake excitation,a water body in a large-scale aqueduct experiences evident vibration,which amplifies the seismic response of the aqueduct.This study proposes a water-passing barrier specifically designed for large-scale aqueducts to mitigate water vibration in the transverse direction.The water-passing barrier is strategically installed in the central line in the aqueduct along the longitudinal direction to divide the water body.The holes are reserved on the water-passing barrier that facilitates the passage of water during water vibration,thereby altering the vibration characteristics of the water body.By inducing water spin,it is possible to dissipate the vibration energy of the water body,ultimately leading to changes in the overall dynamic features of the aqueduct and a reduction in the overall seismic response of the aqueduct.[Methods]To investigate the effectiveness of water-passing barriers for vibration control in aqueducts,shaking table tests were conducted on typical large-scale aqueducts with rectangular and U-shaped sections.Various parameters,including the water height in the aqueduct,the permeability of the water-passing barrier,and the amplitude and frequency of the table motion,were considered during the shaking table tests.Through a comprehensive series of shaking table tests,the dynamic responses of the aqueduct were evaluated under white noise,simple harmonic load,and earthquake excitation.These responses encompass water vibration patterns,natural vibration frequency of the aqueduct,peak acceleration of the cap beam,and other structural responses.[Results]The test results indicated that water-passing barriers could enhance the table acceleration threshold for aqueduct overflow and reduce the vibration of the water body in the structure.The seismic reduction coefficient was quantified as the ratio of the peak acceleration of the cap beam in the aqueduct with a water-passing barrier to that without a water-passing barrier.The seismic reduction coefficient was inf
作者
黄邦辉
李志荣
左澍琼
邓开来
辜文兰
洪彧
HUANG Banghui;LI Zhirong;ZUO Shuqiong;DNEG Kailai;GU Wenlan;HONG Yu(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Central Yunnan Water Diversion Engineering Co.,Ltd.,Kunming 650000,China)
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第7期1147-1156,共10页
Journal of Tsinghua University(Science and Technology)
基金
云南省重大科技专项计划项目(202102AF080001)
四川省科技计划项目(2023YFS0429)。
关键词
渡槽
导水屏障
振动台试验
加速度响应
减震系数
aqueduct
water-passing barrier
shaking table test
acceleration response
seismic reduction coefficient
