摘要
以某公铁立体交叉隧道工程为依托,通过大型振动台试验研究铁路隧道正交下穿公路隧道时的地震响应。分析2个方向(x单向及xz双向)、3种地震烈度(Ⅶ—Ⅸ)、5种地震波加载幅值(0.10g~0.40g)组成的10种加载工况下的隧道振动加速度响应规律,并以地震波幅值0.20g作为振动加速度峰值突变分界点,采用连续小波变换方法分析隧道典型测点的频谱特性。结果表明:隧道的振动加速度响应具有明显的空间分布特征及叠加效应,上跨隧道仰拱处及下穿隧道拱顶处的地震响应更为强烈;x单向输入地震波时,振动加速度叠加效应以下穿隧道拱顶处为主,xz双向输入时以上跨隧道仰拱处为主,且各测点处的振动加速度峰值明显大于x单向;地震波幅值为0.20g~0.30g时,交叉段测点处的振动加速度响应发生突变,地震波幅值为0.30g~0.40g时,加载方向引起的振动加速度放大效应更为明显;Morlet小波在变换尺度为5~20时的中低频率响应更为强烈,随变换尺度的增大,其卓越频率由高频段逐渐向低频段迁移。
Taking a railway tunnel passing through a highway tunnel as an example,the seismic response of railway tunnel perpendicularly undercrossing highway tunnel was studied by large-scale shaking table test.The response laws of tunnel vibration acceleration under 10 loading conditions,which were composed of 2 directions(x unidirectional and xz bidirectional),3 seismic intensities(Ⅶ-Ⅸ)and 5 seismic wave loading amplitudes(0.10 g~0.40 g),were analyzed.The seismic wave amplitude of 0.20 g was taken as the dividing point for the peak mutation of vibration acceleration,and the continuous wavelet transform method was used to analyze the spectral characteristics of the typical measuring points of the tunnel.Results showed that:the vibration acceleration response of the tunnel had obvious spatial distribution characteristics and superposition effect,which made the seismic responses of the invert of the upper-span tunnel and the crown of the under-crossing tunnel more intense.The superposition effect of vibration acceleration was mainly dominant at the crown of the undercrossing tunnel under x unidirectional loading of seismic waves,while it was mainly dominant at the invert of the upper-span tunnel under xz bidirectional loading of seismic waves.Furthermore,the vibration acceleration peak at each measuring point under xz bidirectional loading was significantly greater than that under x unidirectional loading.When the amplitude of seismic wave was 0.20~0.30 g,the vibration acceleration response at the measuring point of the intersection changed abruptly.When the amplitude of seismic wave was 0.30~0.40 g,the amplification effect of vibration acceleration caused by the loading direction was more obvious.Additionally,Morlet wavelet had a more obvious response at low and medium frequencies when the transform scale was 5~20.With the increase of the transform scale,its dominant frequency shifted gradually from high frequency band to low frequency band.
作者
赖天文
雷浩
吴红刚
LAI Tianwen;LEI Hao;WU Honggang(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China;Survey and Design Branch,China Northwest Research Institute Co.,Ltd.of CREC,Lanzhou Gansu 730070,China)
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2021年第3期95-104,共10页
China Railway Science
基金
国家重点研发计划项目(2018YFC1504901)
中铁九局集团有限公司大连分公司科技开发项目(KJ-2019-01)。
关键词
公铁立体交叉隧道
地震荷载
地震波
振动加速度
大型振动台试验
Crossing tunnel of highway and railway
Seismic load
Seismic wave
Vibration acceleration
Largescale shaking table test
