平行螺旋传输线用于岩土形变分布式测量的机理研究

Study of the Mechanism of Parallel Helical Sensing Cable Used for Rock Mass Deformation Distributed Measurement

提出了一种平行螺旋传输线作为传感电缆用于岩土形变位移的分布式测量,基于建立的拉伸分布参数模型,推导了传感电缆特性阻抗与岩土拉伸量的关系并给出了拟合函数。根据编写的上位机程序计算出其特性阻抗的变化从而实现了岩土拉伸位置的定位测量,再利用拟合函数,确定拉伸量的大小,最终求得岩土形变的拉伸总量。为了验证理论分析的正确性,设计了基于时域反射技术的形变测量系统,对平行螺旋传输线进行了局部多点拉伸的定位及形变测量实验,实验测量结果和理论计算结果吻合度很好,为平行螺旋传输线在岩土形变分布式测量的应用提供了有力的理论分析和实验验证。

A kind of parallel helical sensing cable was proposed as a sensing cable for distributed measurement of rock mass deformation.The stretched structure model of distribution parameters for designed parallel helical sensing cable was established to derive the theoretical formula and fitting curve from the stretched deformation and characteristic impedance.The positioning measurement of the rock mass deformation was realized based on change of measured characteristic impedance by the host computer program,the stretched deformation variable was obtained according to the fitting curve,and the amount of stretched deformation was calculated.In order to verify the correctness of the theoretical analysis,the multi-point stretching positioning and deformation measurement experiment of parallel helical sensing cable were carried out on the designed tensile measurement system based on the time domain reflection technique.The measurement results are in good agreement with the theoretical calculation results which provides a powerful theoretical analysis and experimental verification for the application of parallel spiral transmission lines in distributed measurement of rock mass.