基于小波变换的黄土滑坡动土压力响应及其频谱特性研究  

Study on spectrum characteristics of dynamic earth pressure of loess landslides based on wavelet transform

作　　者：施艳秋 谢显龙 张玘恺 蒋翰 彭嘉骏 廖昕 SHI Yanqiu;XIE Xianlong;ZHANG Qikai;JIANG Han;PENG Jiajun;LIAO Xin(College of Railway Engineering,Jilin Railway Technology College,Jilin,Jilin 132200,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan,Hubei 430063,China;Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu,Sichuan 611756,China;Zhejiang Engineering Survey and Design Institute Group Co.,Ltd.,Ningbo,Zhejiang 315012,China)

机构地区：[1]吉林铁道职业技术学院铁道工程学院,吉林吉林132200 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063 [3]西南交通大学地球科学与环境工程学院,四川成都611756 [4]浙江省工程勘察设计院集团有限公司,浙江宁波315012

出　　处：《岩石力学与工程学报》2020年第12期2570-2581,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：铁道部科技研究开发计划课题(2011G012-A);吉林省职业技术教育学会年度科研重点课题(2018XHZ012)。

摘　　要：为了探讨黄土边坡在地震作用下动土压力沿高程和滑面的频谱特性响应规律,通过大型振动台实验输入X向和Z向地震波,并逐级加载直到边坡破坏,获取沿高程和滑面附近5个传感器的动土压力曲线,并利用基于小波变换的小波包分析工具将动土压力时域曲线分解,结果表明:(1)输入EL-Centro波逐级加载过程中,各测点动土压力响应效果显著,在强大惯性力的作用下,动土压力峰值不断增大,动土压力沿高程向上呈现不断减小的趋势;(2)土压力沿滑面从坡脚到坡体内部呈现不断增大的趋势,S-1与S-3测点之间的直线斜率大于S-3与S-5测点之间的直线斜率,说明加载过程中滑坡前部围岩一直保持挤密状态,而后部S-5测点更容易受干扰因素影响造成土压力值变化;(3)第一频带小波分量(0.1~6.26 Hz)和第二频带小波分量(6.26~12.51 Hz)的低频地震应力波对动土压力影响最为突出,黄土斜坡对高频波的吸收效果较好;(4)各通道第一频段和第二频段动土压力曲线与实测曲线规律相近,第三~第八频段规律相差较大,低频波在动土压力响应中起主导作用,黄土边坡对地震波沿高程运动过程中高频部分具有"滤波作用"。In order to investigate the response spectrum characteristics of the dynamic soil pressure along the elevation and sliding surface of loess slopes under the action of earthquake,large-scale shaking table experiments were performed by progressively loading X-direction and Z-direction seismic waves until failure of the slope.The dynamic soil pressure curves of 5 sensors along the elevation and near the sliding surface were obtained,and the time-domain curve of the dynamic soil pressure was decomposed by using wavelet transform.The results show that,in the process of step loading through inputting EL-Centro wave,the response of the dynamic soil pressure at each measurement point is significant,and that the peak value of the dynamic soil pressure is increasing under the action of the inertial force while the dynamic soil pressure is decreasing along the elevation.The soil pressure is increasing from the foot to the inside of the slope along the sliding surface,The slope of the straight line between the measuring points S–1 and S–3 is greater than that between the measuring points S–3 and S–5,indicating that,in the loading process,the front of the landslide maintains compaction state while the S–5 point in the rear is more likely to be disturbed.The low-frequency seismic stress wave of the wavelet components of the first frequency band(0.1 to 6.26 Hz)and the second frequency band(6.26 to 12.51 Hz)has the most significant effect on the dynamic earth pressure,playing a leading role in the response of the earth pressure.The dynamic earth pressure curves under the first and second frequency bands of each channel are similar to the measured curves,while them are quite different from each other under the third and eighth frequency bands.The low-frequency wave plays a dominant role in the response to the soil pressure,and the loess slope has a"filtering effect"on the high-frequency part of the seismic wave moving along the elevation.

关 键 词：边坡工程 黄土边坡 动土压力 频谱特性 振动台 滑面 高程 小波变换 

分 类 号：P64[天文地球—地质矿产勘探]