Research On Automatic Deformation Monitoring Scheme Based On 3D Model Of Metro Tunnel

In recent years,the subway has eased traffic pressure in large and medium-sized cities.Metro rail transit construction has become a major project in urban construction.In the construction and operation of subway tunnels,many external factors will affect the main structure of the tunnel,such as the geological conditions in the construction area,the load on the ground buildings,the excavation of the foundation pits around the tunnel,groundwater and high-speed subway trains.Etc.to make it deform horizontally or vertically.If real-time dynamic monitoring is not possible,tunnel deformation cannot be found in time,resulting in a very serious engineering accident.The prerequisite for the realization of automatic subway deformation monitoring is the deployment of deformation monitoring networks such as working base points,reference points and monitoring points.The main objects of deformation monitoring are track bed settlement,vault settlement,tunnel horizontal displacement,horizontal convergence,differential settlement of the two rails(after rail laying).The traditional layout method is to lay out on the two-dimensional graphic design.The main problems are the following three points.First,the object expression is not intuitive,and the spatial position of each deformation monitoring point in the tunnel cannot be presented three-dimensionally;second,the paper graphic design The information of the drawings will be lost with the increase of the time dimension,so that the structural information of the tunnel cannot be restored;third,the two-dimensional plane information is too abstract,and the two-dimensional plane design can only convert the plane information into three-dimensional information through the imagination of professional technicians.,The usage is too limited.Compared with the traditional two-dimensional plane drawings,the three-dimensional model can not only present the basic structure of the target object more intuitively,but also view the target object in any view.For underground tunnels with complex terrain,the use of a three-dimensional spatial model for subway tunnels is significantly better than the traditional two-dimensional plan design.Based on BIM's three-dimensional modeling technology,this paper expresses the subway tunnel in three-dimensional way,and lays out the deformation monitoring network based on the automatic monitoring scheme.With the measurement robot TM-50 as the monitoring device and BIM+Dynamo as the technical support,the advantages of the three-dimensional model in the automatic monitoring scheme of the subway tunnel are studied to realize the visualization,transparency and manageability of the underground tunnel.The main contents of this article are as follows:(1)Introduce the workflow of TM-50 measuring robot and the data processing process of GeoMos monitoring software in detail;(2)The layout of the monitoring points,monitoring sections,working base points,reference points and the design of the monitoring cycle in the automatic monitoring program;(3)Parametric modeling of subway tunnels based on BIM technology,based on the fine division of the three-dimensional model of the tunnel,create a three-dimensional model of the subway tunnel,realize the visualization of the three-dimensional model of the main body of the subway tunnel,and monitor the network points(working base point,monitoring point,reference point))Arranged on the three-dimensional model of the tunnel to complete the attribute information query and spatial location visualization of the monitoring points;(4)Carry out spatial analysis on the basis of the three-dimensional model of the tunnel to judge the rationality of the arrangement of monitoring points.Through the actual engineering research of the subway tunnel,the three-dimensional model shows the advantages of visualization and manageability in the automatic monitoring scheme of the subway tunnel and determines the fine level of the three-dimensional model of the tunnel.Technicians can directly deploy the deformation monitoring network points on the three-dimensional model of the subway tunnel.Not only can the two-dimensional plane layout design map be intuitively presented on the three-dimensional space model,but also the relevant attribute information of the monitoring points can be queried.Finally,the spatial analysis technology of three-dimensional simulation is used to realize the reasonable judgment of the deformation monitoring network layout,and the optimal spatial layout position of the monitoring point is obtained.