不同激振频率下云桂铁路路堑基床振动特性现场试验  

In-situ Test on Vibration Characteristics of Cuting Subgrade Bed of Yunnan-Guangxi Railway under Different Excitation Frequencies

作　　者：王亮亮 薛元[3] 柳志军[1,2] 刘江涛[3] 封志军[3] 龚建辉[3] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与建筑工程学院,江苏徐州221116 [3]中国中铁二院工程集团有限责任公司,四川成都610031

出　　处：《铁道学报》2017年第12期118-123,共6页Journal of the China Railway Society

基　　金：中国博士后科学基金(2010M591957)

摘　　要：利用大型激振设备对铺设柔性复合防排水板的云桂铁路膨胀土路堑基床进行扫频试验,研究该基床的共振频率及不同基床位置动应力和加速度随激振频率的变化规律。试验结果表明:膨胀土路堑基床的共振频率约为17Hz;路基面以下1.2m深度范围内,动应力沿深度的实际衰减速度明显高于布氏理论计算结果;动应力和加速度沿深度方向的衰减规律与激振频率大小有关,激振频率小于15Hz时,二者均呈指数型衰减,随着激振频率的进一步增加,动应力衰减规律向ε型转变,加速度衰减规律向线性衰减转变;在基床表层底面水平方向上,激振荷载的显著影响范围小于轨道中线两侧1.76m。Frequency scanning dynamic test was carried out on the expansive soil cutting subgrade of YunnanGuangxi Railway with flexible composite waterproof plate by using large scale exciting equipment.The resonant frequency of the subgrade and the variation laws of the dynamic stress and acceleration with excitation frequency at different subgrade positions were studied.The results show that the resonance frequency of the expansive soil cutting subgrade is approximately 17 Hz.The measured dynamic stress attenuation velocity along the depth within the range of 0~1.2 munder the surface of the subgrade was faster than the calculation results of Boussinesq Theory.The attenuation curves of dynamic stress and acceleration in vertical direction are related to the excitation frequency.When the excitation frequency is less than 15 Hz,both show exponential decay.With the increase of the excitation frequency,the dynamic stress attenuation model gradually turns to＂ε＂model and the acceleration attenuation model turns to liner attenuation model.In the horizontal direction of the bottom of the graded broken stone layer,the significant influence range of the exciting load is less than that at 1.76 mfrom railway central line.

关 键 词：路堑 铁路基床 共振频率 现场试验 

分 类 号：U213.12[交通运输工程—道路与铁道工程]