Study On The Methods Of Subway Tunnel Deformation Monitoring Based On Total Station Scanner

With the rapid development of economy,the urbanization process of our country becomes faster and faster.In order to alleviate the traffic congestion problems accompanied with urbanization,urban rail transportation networks are being built up in more and more first-tier and second-tier cities.Because the construction of metro inevitably change the geotechnical structure,some deformations of subway tunnel can not be avoid.And the buildings and vehicles will aggravate these deformations.If we can not monitor and control these deformations,there will be serious security risks which can cause huge loss to our society and citizen.So we have to find useful methods to monitor the deformations of subway tunnel.The traditional monitoring methods have 1 their own strengths as well as weakness.Applying the total station scanner to monitoring subway tunnel,will be a perfect solution to the monitoring of subway tunnel.Because the total station scanner combines the high precision of total station instrument with the rapid scanning of 3-d laser scanner.The purpose of this paper is trying to clarify how to use total station scanner in the monitoring of subway tunnel.In the first part of the mainbody,the author tries to introduce the two different use of total station scanner.The first one is to use it with the single point method to do profile measurement and the second one is to use it with the point cloud method to do profile extraction.In the second part,the author is trying to explain how to combine these tow different use to monitor the deformations of subway tunnel.Firstly,compare the two profile circle which respecti-vely come from single point method and point cloud method,thus to verify the reliability of this two different way.Secondly,use the point cloud which is collected by the total station scanner to draw a curve graph of deformation.Thirdly,project the central axis of the tunnel's point cloud to the XOY planes to analyze the displacement of the tunnel and then project the central axis to the ZOY planes to analyze the sedimentation of the tunnel.Fourthly,estimate the deformation of each profile by analyze the difference between ellipse fitting of several periods.In the last part of this paper's mainbody,based on several common deformation analysis forecast model,the author tries to develop a new analysis forecast system of subway tunnel deformations and test this system with measured data.This paper focus on using total station scanner to do deformation monitoring,analysis and forecast.The author puts forward this assumption and tests it with measured data,thus provide a new method for the deformation monitoring of subway tunnel.