摘要
以成兰铁路沿线的桩板墙加固边坡为原型,设计并完成了几何相似比为1:10的地震动模拟振动台试验,并采用HHT时频分析方法分析桩板墙加固边坡地震响应特性,研究结果表明:在加载不同幅值地震波过程中,板式挡墙加固堆积体滑坡的加速度响应表现出明显的高程效应,且在0.3g地震波作用下,滑坡的高程效应最为显著,然后随幅值增大高程效应逐渐减弱。桩板式挡墙的桩身动土压力沿桩身呈非线性分布,其包络线的大小和范围与地震波幅值成正比。桩身最大动土压力出现在嵌入截面处,故需注意该部位的加固设计。桩身的位移响应同样随地震波幅值逐渐增大,耦合位移模式则由以平动为主转变为转动为主。此外,利用基于HHT变换的时频分析方法研究桩板式挡墙加固堆积体滑坡地震稳定性是可行的。通过Hilbert能量谱分析得到地震能量主要集中在2~6 s时域范围内,对应的频域为10~50 Hz。随着输入地震波幅值的增加,滑床和滑体测点的Hilbert能量在时频域上的差异性增大,两者的地震响应差异性显著增大。通过Hilbert边际谱可以识别到滑坡内部的损伤情况,受桩板式挡墙作用滑坡底部的损伤主要发生在坡面,而滑坡中部的损伤主要发生在内部。
The time-frequency analysis method based on Hilbert-Huang transform is proposed and used to the seismic response analysis of accumulation landslide reinforced by pile-plate retaining wall.Taking the landslide along the Chengdu-Lanzhou Railway as the prototype,the shaking table test of the accumulation landslide reinforced by pile-plate retaining wall with a physical dimension similarity ratio of 1:10 is designed and carried out.The results show that the acceleration response of the accumulation landslide shows obvious elevation effect in the process of loading different amplitude seismic waves,and the elevation effect of the landslide is the most significant under the 0.3g seismic wave.Then the elevation effect decreases with the increase of seismic wave amplitude.The dynamic earth pressure of the pile is distributed nonlinearly along the pile body,and the size and range of its envelope are directly proportional to the seismic wave amplitude.The maximum dynamic earth pressure of the pile appears at the embedded section,so attention should be paid to the reinforcement design of this part.The displacement response of pile also increases gradually with the seismic amplitude,and the coupling displacement mode changes from translation to rotation.In addition,it is feasible to use the time-frequency analysis method based on HHT transform to study the seismic stability of accumulation landslide reinforced by pile-plate retaining wall.The Hilbert energy spectrum analysis shows that the seismic energy is mainly concentrated in time domain of 2-6 s,and the corresponding frequency domain is 10-50 Hz.With the increase of input seismic amplitude,the difference of Hilbert energy between sliding bed and sliding body measurement points in time-frequency domain increases,and the difference of seismic response between them increases significantly.The damage inside the landslide can be identified by Hilbert marginal spectrum.Under the action of pile plate retaining wall,the damage at the bottom of the landslide mainly occurs on the
作者
连静
丁选明
张良
LIAN Jing;DING Xuan-ming;ZHANG Liang(School of Civil Engineering,Chongqing University,Chongqing 400044,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610036,China)
基金
Project(52078426)supported by the National Natural Science Foundation of China
Project(2018YFE0207100)supported by the National Key Research and Development Project of China。
