Research On Slope Activity Monitoring And Prediction And Early Warning

Slope activity monitoring and forecasting are extremely important theoretical and engineering issues.How to establish activity monitoring methods,analyze slope stability through monitoring results,establish slope activity forecasting methods and early warning indicators,is to reduce landslides.key to disaster issues.In this paper,taking the Xianghuling slope project in Hangzhou as the research object,the slope activity monitoring method is established by the digital speckle correlation method and the SIFT feature point method,and the accuracy of the activity calculation method is verified.The speckle correlation method and the finite element method are combined to establish a mechanical parameter inversion method,and the evolution law of elastic modulus,Poisson’s ratio,cohesion and internal friction angle in the whole process of material failure is obtained.According to the real-time displacement field data of the slope,combined with The mechanical parameter inversion method is used to obtain the time evolution law of the slope mechanical parameters,and the time and space evolution law of the displacement field is obtained.In the prediction research,the safety factor of the slope and the displacement field data under the imminent sliding state are obtained by the finite element strength reduction method,and the slope early warning research is carried out,and finally the slope activity monitoring and prediction early warning system is formed.In terms of mechanical parameter inversion,the inversion method of elastic and elastoplastic parameters was constructed by combining the activity calculation method and finite element simulation,and the three-point bending experiment of granite and similar model test of surrounding rock were carried out to analyse the evolution law of the measured displacement field during the loading process.The main research results are as follows:In terms of slope activity monitoring,firstly,according to the purpose and principle of slope activity monitoring,a slope activity monitoring system based on photogrammetry technology is established.This system is composed of hardware system and software system.Then,combined with the digital speckle correlation method and the SIFT feature point method programming,the slope activity calculation method is established,and the real-time,full-field and all-weather automatic monitoring of the slope is realized.Finally,the accuracy of the activity calculation method is verified.In terms of slope activity prediction,a slope activity prediction method is proposed,and a mechanical parameter inversion method is established by combining the activity calculation method and finite element simulation,and the evolution law of the slope mechanical parameters with time is obtained.To predict the activity,the temporal and spatial evolution law of the displacement field is analyzed,and the threshold value of the slope activity prediction method is proposed.Firstly,the three-point bending experiment of granite and the similar model test of surrounding rock were carried out,the evolution law of the measured displacement field during the loading process was analyzed,the inversion objective function of elastic and elastoplastic mechanical parameters was constructed,and the elastic and elasto-plastic mechanical parameters were realized through optimization algorithm.The mechanical parameters obtained by inversion are substituted into the finite element model for forward analysis,and the feasibility and rationality of the two mechanical parameter inversion methods are verified.In terms of slope activity early warning,a four-level slope activity early warning criterion is established.First,the tangent angle and displacement rate are considered,and the early warning criterion for different evolution stages is established.The displacement field in the sliding state is used as the criterion for the imminent sliding displacement.Based on the above warning criteria,the slope warning grades are divided into four grades: blue,yellow,orange,and red.Then,uniaxial compression tests of red sandstone and granite were carried out to predict the time,location and energy of failure,and to verify the feasibility of the activity prediction and early warning method.In terms of engineering application,taking the Xianghuling slope project in Hangzhou as the research object,the slope activity monitoring and forecasting and early warning methods proposed in this paper are applied in engineering.Firstly,according to the engineering situation of the slope,an on-site monitoring layout plan was established,and the slope activity monitoring method was used to monitor the Xianghuling slope,and the slope activity results were obtained,and the temporal and spatial evolution law of the displacement field was analyzed;The slope activity prediction method is used to obtain the evolution law of the slope mechanical parameters with time.After passing the prediction threshold,the slope activity is predicted.Finally,according to the slope activity early warning method,the early warning level of the slope is obtained.The slope is currently at a blue warning level.