基于螺旋平行传输线的时域反射监测技术研究

Time—Domain Reflectometry Monitoring Technology Research Based on Spiral Parallel Transmission Line

针对山体滑坡、泥石流等岩土灾害,通过基于螺旋平行传输线的TDR(time-domain reflectometry)技术,设计出的窄脉冲发生电路,返回波信号调理电路和高速采样模块,运用等效采样法,实现了信号的采集,完成了时域反射监测仪器系统,并对反射波形进行了实时对比研究;将螺旋平行传输线埋人山体,当山体内部发生形变,引起螺旋平行传输线相应拉伸,拉伸点的特性阻抗随之变化,运用TDR技术对螺旋平行传输线进行测量分析,可得螺旋平行传输线变形数据,相应的反映了山体表面的变形;反射波形的实时对比研究表明,将时域反射技术应用于螺旋平行传输线形变监测行之有效且效果明显。

Aiming at the measurement of landslides, mudslides and other geotechnical hazards, narrow pulse circuity, return signal con ditioning circuitry and high--speed sampling module , which can achieve the signal acquisition and complete a TDR monitoring instrument system hy using equivalent sampling method and then undertake comparative study of the real--time reflection waveform, were designed by means of the TDR technology based on spiral parallel transmission line. Spiral parallel transmission line is buried in the mountain. When the deformation occurs in the mountain, the parallel transmission line is correspondingly stretched, and the characteristic impedance of the tensile point is changed. Then using TDR technology to measure and analyze the parallel transmission line, the deformation data of the parallel transmission line which can correspondingly reflect the deformation of the surface of the mountain can be got. The comparative study of the real--time reflection waveform testified that using the TDR technology to monitor spiral parallel transmission line＇ s deformation is effective and obvious.