| Deformation monitoring is an important supporting means for the stability analysis of bridges,dams and high-rise buildings and the monitoring of geological disasters such as landslide,debris flow and surface subsidence.Through the analysis and research of monitoring data,early warning and prediction can greatly reduce the loss of people’s lives and property.Micro Deformation Monitoring Radar can monitor the deformation and displacement of the observation area in all day,all-weather,non-contact,large area and submillimeter accuracy,and has become an important monitoring means to actively prevent geological disasters.However,there are few researches on the analysis of the area point group obtained by the Micro Deformation Monitoring Radar after the surface monitoring.Based on the landslide early warning model and method based on the conventional point monitoring,this paper studies and explores the landslide early warning model and method suitable for the surface monitoring.At the same time,the accuracy analysis,deformation extraction algorithm and application of the portable omni-directional Micro Deformation Monitoring Radar used in this paper are carried out Research on deformation monitoring experiment.The main contents include:1.This paper studies the factors that affect the monitoring accuracy of Micro Deformation Monitoring Radar from two aspects of observation target layout and signal-tonoise ratio(SNR),analyzes the influence degree of each factor on the monitoring accuracy under different conditions,and verifies it by simulation.2.Firstly,the one-dimensional and two-dimensional signal models of the omnidirectional rotary micro deformation monitoring radar are derived;secondly,the onedimensional deformation monitoring experiment is designed,in which the strong reflector such as the corner reflector is used as the observation target,and the optical prism is rigidly connected with the corner reflector,and the data are compared with the omni-directional micro deformation monitoring radar through the radar monitoring results Finally,the distributed corner reflector is used to simulate the observation scene to analyze the twodimensional deformation monitoring accuracy of the micro deformation monitoring radar.The experimental results of one-dimensional and two-dimensional deformation monitoring show that the monitoring results are in good agreement with the actual displacement.The average measurement value of the designed reference corner reflector is within 0.1 mm,and the deformation monitoring accuracy of the system can reach sub millimeter level,which can realize the application of high-precision micro deformation monitoring.3.In view of the problem that the existing early warning methods of micro deformation monitoring radar only judge the slope stability state for the displacement velocity and displacement increment of a single pixel or a small area in a certain monitoring section,it is likely to be misjudged.Based on the point group data obtained by ground-based micro deformation monitoring radar after surface monitoring,this paper puts forward a new method based on multi thresholds The method is applied to the actual Micro Deformation Monitoring Radar system.Taking a small landslide and an open pit mine as examples,the feasibility and effectiveness of the proposed method are analyzed and verified.The results show that this method can be effectively used in slope early warning,and reduce the false alarm rate.It can provide accurate and timely early warning information for decision makers,and provide strong method support for slope landslide monitoring and early warning. |
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