Development Of A Landslide Monitoring System Using TDR Technology

The geological disaster has ben the focus of national natural disaster prevention,the landslide is one of the serious ones.Therefore,perple pay more and more attention to the early warning of the landslide disaster.Andmany domestic landslide monitoring projects and the scientific research are using the expensive monitoring instrument of foreign.Such as Campbell Scientific TDR100,Tektronix 1502C/CS series etc..At the same time these instruments need to purchase foreign-related ancillary equipment.Due to the expensive price,these systems are generally only used to monitor the large-scale landslide,but has not been widely used in the small landslide.This paper firstly describes the basic principles of how to use TDR(Time Domain Reflectometry)technology to monitoring the landslide.And then study the theory of how the pulse signal transmis in the coaxial cable.Finally,the paper design a TDR landslide monitoring system which includes the hardware and the software.This system is composed of three parts:the coaxial cable,the lower computer hardware circuit, computer application software.The lower computer hardware circuit transmits a narrow pulse signal to the coaxial cable,at the same time,the system sampling the transmits narrow pulse and the reflect pluse from the coaxial cable.And then cache the equivalent sampling datas.Finally the system transmittes all the datas to the PC by using the USB.The application software of PC will be responsible for reconstrucing waveform from the collecting datas,displaying the waveform,analysising and processing the datas.According to the conditon of the landslide body,the system will judgt whether to need send the landslide erarly warning.There is a laboratory test of TDR system at the end of this paper.By using the cutting device to simulate the coaxila cable’s extrusion and shearing by the landslide,records a large number of datas.The calculation model of TDR is verified by the testing datas and it confirmes the availability of the TDR system and the correctness of the calculation model.