The Research For Ground Collapse Distributed Measurement Technology Based On Spiral Parallel Cable

In recent years,the surface collapse problem caused by exhaustive exploitation of mineral resources happens frequently.As one of the major disaster types of geological disaster,surface collapse gives rise to huge threat of national economic construction and people's lives and properties.Therefore,the measurement of surface collapse is of great theoretical significance and engineering value.On the basis of coaxial cable structure,this thesis proposes a new type of sensor,the spiral parallel line.Compared with coaxial cable,the spiral parallel line features larger stretching deformation quantity and the helical-circling copper wire would fracture constantly in the course of stretching.The spiral parallel line is more suitable for distributed measurement of surface collapse and deformation.Its stretching deformation quantity can reflect the degree of surface collapse and the deformation position is correspondent to the position of surface collapse.By study of characteristic impedance of general uniform transmission line,this thesis mainly proposes the theoretical calculation method of distributed capacitance,distributed inductance and characteristic impedance of spiral parallel line.In addition,relative instruments are used to verify the conclusion that the distributed capacitance,distributed inductance and characteristic impedance would decrease along with the increasing of stretching deformation quantity through experiment.This thesis designs a kind of structure which is suitable to experiment of spiral parallel line.In the same time,this thesis designs a kind of software system of upper computer which is matched with the distributed measurement of spiral parallel line.This thesis studies some data processing method and mathematical model algorithm.On the basis of time-domain reflectometry technology,distributed measurement model of spiral parallel line is established,which obtained favorable results and calibration recognition of Zhejiang Measurement Institute.Among the distributed measurement results of spiral parallel line,the relative error of deformation position measurement is ±1.47% and the relative error of deformationmeasurement is ±3.67%.