摘要
为了研究分层土地基(上层为粘土层,下层为砂层)条件下几何参数对单排混凝土桩的隔振效果,该试验通过缩尺比例为1∶15的缩尺模型试验,以激振器作为点振源产生振动波向四周扩散,通过对比单排桩前后两侧振动加速度极值,清晰地展现出了单排桩对振动波的的影响区域,并得到了几何参数的隔振影响作用。在该试验条件下得出结论:相对于其他影响因素,桩长是影响隔振效果的重要参数,当桩长参数由0.28增至0.57时可提高约9%的隔振面积,同时增加桩长和隔振区长度可使隔振区域振幅大幅度减小与有效隔振面积大幅增加,但同时会造成桩前一侧振动增强;对于低频振动,单排桩隔振屏障对中频和高频有更好的隔振作用,该试验条件下隔振效果可相差约3%,且频率越高,穿透性越强,且将在桩后形成一个振动加强区;增加振源距可有效提高隔振效果,但当频率较低时,中远振源的隔振效果相近。
In order to study the effect of geometric parameters on the vibration isolation performance of a single row of concrete piles under the condition of layered soil foundation(the upper layer is clay and the lower layer is sand),an experiment with a reduced scale of 1∶15 was carried out and an vibricator was used as a point vibration source to generate vibration waves that spread around.By comparing the peak values of the vibration accelerations at the front and back of the single-row pile,the influence area of the single-row pile on the vibration wave is clearly displayed,and the effect of the vibration isolation of the geometric parameters is obtained.It is found from this study that,in layered foundations,the pile length is an important parameter that affects the vibration isolation effect compared with other influencing factors.When the pile length index increased from 0.28 to 0.57,the vibration isolation area was enlarged by about 9%.The length can greatly reduce the vibration amplitude of the isolation area and increase the effective vibration isolation area,but will also cause stronger vibration on the front side of the pile.Compared with low frequency vibration,the single row pile vibration isolation has better vibration isolation effect for medium and high frequencies.Under the test conditions,the maximum difference of vibration isolation effect is 4%,higher the frequency presents stronger the penetration and a vibration strengthening area will be formed behind the pile.The vibration isolation effect can be effectively improved by increasing the vibration source distance,but when the frequency is low,the vibration isolation effect is similar for the median or far vibration source.
作者
刘晶磊
张冲冲
刘航
梅名彰
LIU Jinglei;ZHANG Chongchong;LIU Hang;MEI Mingzhang(Hebei Key Laboratory of Civil Engineering Diagnosis,Reconstruction and Disaster Resilience,Zhangjiakou 075000,China;Technology Innovation Center for Transportation Infrastructure Engineering in Cold Regions of Hebei Province,Zhangjiakou 075000,China;School of Civil Engineering,Hebei Institute of Civil Engineering and Architecture,Zhangjiakou 075000,China)
出处
《世界地震工程》
CSCD
北大核心
2021年第2期132-142,共11页
World Earthquake Engineering
基金
河北省青年拔尖人才计划项目(BJ2016018)
张家口市科学技术研究与发展计划项目(1811009B-13)
河北建筑工程学院创新基金项目(XY2020004)。
关键词
隔振效果
单排桩
上软下硬地基
隔振区域
vibration isolation effect
single row of piles
upper soft lower hard foundation
vibration isolation area
