摘要
为研究正弦波与EL波作用下抗滑桩支挡的高陡边坡桩身前后土压力响应差异,设计完成振动台试验进行响应分析。桩身前、后土压力分别呈倒三角形及抛物线型分布,峰值分别位于靠近桩顶、滑面附近,且桩后土压力略大于桩前。因存在频段耦合效应,正弦波与EL波产生的桩身前、后土压力峰值的差值随加速度峰值的提高较为波动,整体在0.5g达到峰值,分别达到3.242 kPa和2.268 kPa。通过FFT分析,EL波作用下,相对于桩后土压力,桩前土压力具有更强的低频放大效应;桩后土压力在高震级时,其次频带内的最大峰值频率会有较明显向低频带靠近的趋势。利用小波包分析频带划分均匀和时频局部化特性,得到2个峰值点处各频带小波重构分量。结果表明,正弦波与EL波工况下都是测点土压力第1频带(0~6.25 Hz)重构信号较为接近原始信号,即加载波卓越频率所在子频带对土压力响应影响最大,且就第1频带重构分量土压力最大值数值而言,正弦波约为EL波的1.15~1.85倍。此外,大震级时EL波第2频带(6.25~12.50 Hz)小波分量对桩后土压力影响较大。考虑到地震波的成分复杂,常用试验加载波正弦波与实测EL波在时域、频域特性差异较大,所引起的响应存在不同,因此对于边坡工程中支挡结构的抗震性能研究,应选择实测天然地震波作为加载波。
In order to study the difference of soil pressure response before and after the anti-sliding pile supporting the high and steep slope under the action of sine wave and EL wave,the response analysis was carried out by designing and completing the shaking table test.The soil pressures before and after the pile body were distributed in an inverted triangle and a parabolic shape,and the peaks were located near the top of the pile and near the sliding surface,respectively.And the soil pressure behind the pile is slightly larger than that before the pile.Due to the frequency band coupling effect,the difference between the peak values of the soil pressure before and after the pile generated by the sine wave and the EL wave fluctuates with the increase of the peak value of the loading acceleration,reaching the peak value at 0.5g,reaching 3.242 kPa and 2.268 kPa,respectively.Through FFT analysis,under the action of EL wave,the earth pressure before the pile has a stronger low-frequency amplification effect than the soil pressure behind the pile.When the earth pressure behind the pile is at a high magnitude,the maximum peak frequency in the secondary frequency band will tend to be closer to the low frequency band.Wavelet packet analysis is used to analyze the frequency band division uniformity and timefrequency localization characteristics,and the wavelet reconstruction components of each frequency band at two peak points are obtained.The reconstructed signal of the first frequency band(0~6.25 Hz)of the earth pressure is close to the original signal under sine wave and EL wave conditions.That is,the sub-band of the carrier frequency has the greatest influence on the earth pressure response.In terms of the maximum earth pressure of the first frequency band reconstructed component,the sine wave is about 1.15~1.85 times of the EL wave.In addition,the second band(6.25~12.50 Hz)wavelet component of EL wave has a great influence on the soil pressure behind the pile at large magnitudes.Considering the complex composition of seism
作者
陈虹羽
蒋关鲁
何晓龙
刘勇
田鸿程
CHEN Hongyu;JIANG Guanlu;HE Xiaolong;LIU Yong;TIAN Hongcheng(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of High-Speed Railway Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;POWERCHINA Chengdu Engineering Co.,Ltd.,Chengdu 611130,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第5期1708-1717,共10页
Journal of Railway Science and Engineering
基金
四川省科技计划资助项目(2018GZ0057)
国家自然科学基金资助项目(51878577)。
关键词
正弦波
EL波
边坡与抗滑桩
动土压力
小波包
振动台
sine wave
EL wave
slope and anti-slide pile
earth pressure
wavelet packet
shaking table
