摘要
为研究桩、土相关参数对微型桩基动力响应的影响,进行了RPC微型桩基动力响应振动台试验。分析了微型桩在动力荷载激励下桩土体系的加速度时程、应变时程反应以及单桩桩身弯矩、变形的分布情况。通过对白噪声作用下的频谱分析图进行分析,发现RPC微型桩在5 Hz和16 Hz附近存在固有频率;在多次白噪声作用下,砂土的密实程度有所增加,微型桩的固有频率也有所增大。通过对加速度响应图进行分析,发现人工波作用下的加速度放大效果最显著,其次为EI-Centro波,最小为Kobe波,这是因为人工波的作用频率最接近微型桩的固有频率;在4 Hz频率、0. 15g幅值的正弦波作用下,微型桩的最大应变分布约为4倍桩径的埋深位置;在不同频率正弦波作用下,微型桩的最大弯矩值均出现在埋深0. 6 m位置;在3种地震波作用下,人工波作用下的桩身弯矩和变形反应最大,EICentro波作用次之,Kobe波最弱,这是由于人工波的频率成份较为丰富,正弦波所含频率单一,而地震波所含频率丰富,这使得地震波作用下的反向变形更为明显。
In order to study the influence of the relevant parameter of pile and soil on the dynamic response of micro pile foundation,a shaking table test on dynamic response of micro RPC pile is carried out. the acceleration time history reaction and strain time history reaction of pile-soil system as well as the distributions of the moment and deformation of single pile under dynamic load excitation are analyed. By analyzing the spectrum under the action of white noise,it is found that( 1) the natural frequencies of RPC micro pile exist near 5 Hz and 16 Hz,( 2) under the influence of repeated white noise,the compactness of sand increases,and the natural frequency of micropile increases too. By analyzing the acceleration response curve,it is found that( 1) the acceleration amplification under artificial wave is the most significant,followed by EI-Centro wave,Kobe wave is the smallest,because the action frequency of artificial wave is the closest one to the inherent frequency of the micro pile,( 2) under the action of sine wave with 4 Hz frequency and 0. 15 gamplitude,the maximum strain of the micro pile is located at the depth of 4 times of the pile diameter,( 3) under the action of sine wave with different frequencies,the maximum bending moment appears at the depth 0. 6 m,( 4) under the action of 3 kinds of seismic wave,the bending moment and deformation responses of artificial wave is the biggest,the action of EI-Centro wave is second,and the Kobe wave is weakest,because the frequency component of artificial wave is more abundant,the frequency of sine wave is single,while the frequency of seismic wave is rich,which makes the reverse deformation under the action of seismic wave more obvious.
作者
林上顺
陈国栋
庄一舟
黄福云
徐亮
LIN Shang-shun;CHEN Guo-dong;ZHUANG Yi-zhou;HUANG Fu-yun;XU Liang(Fujian Provineial Key Laboratory of Advanced Teehnology and Informationization in Civil Engineering,Fujian University of Technology,Fuzhou Fujian 350118,China;School of Civil Engineering,Fuzhou University,Fuzhou Fujian 350108,China;School of Civil Engineering and Arehiteeture,Zhejiang University of Technology,Hangzhou Zhejiang 310023,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2019年第2期36-42,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51578161)
国家自然科学基金项目(51778147)
浙江省自然科学基金项目(LY17E080022)
福州市科技局市校合作项目(2016-G-62)
关键词
桥梁工程
微型桩
振动台试验
桩土相互作用
无缝桥
bridge engineering
micro pile
shaking table test
soil-pile interaction
jointless bridge
