Study On BIM Design Method For Reconstruction Of Existing Railway

It calls for higher travel quality for passengers as the continuing expansion and improvement of railway network,many existing railway lines need to be revamped to meet the demands of speed acceleration.The reconstruction design of existing railway,which is limited by the structures alongside railway lines and reconstruction scope,puts forward higher requirements for the survey,selection of technical schemes in designing work.Aspects including improvement of surveying technology,construction of BIM Model and realization of dynamics evaluation concerning railway reconstruction schemes shall be taken into consideration to better solve the issue;the adoption of 3D-visualized design method of existing railway reconstruction will undoubtedly contribute to obtaining economical and reliable schemes.For this purpose,the thesis mainly studies the following contents:(1)Construction of BIM Model applicable to existing railwayThe DTM of the section which needs to be reconstructed was built via Civil3 D Platform by utilizing the elevation information extracted from the plane and profile section data of an existing railway line;by importing the data including the railway structure,plane and profile sections to the previously built DTM according to the reconstruction requirements of the BIM Model,the model integrates center line,profile,cross section,track structure,bridges and tunnels was built via OpenRail.The automatic matching of section type with mileage and terrain will realize by cross-section design module,and via interactive computing provided by Autodesk InfraWorks,a seamless connection with terrain model was reached,then the model of existing railway which is applicable to BIM reconstruction was thus built.(2)3D visualized reconstruction design method applicable to existing railway BIM modelThe radius transformation of common reverse curve was taken as an example to demonstrate the plane & profile section calculation under three different combination of radii,the integration of models including subgrade,bridges,tunnels and track,together with DTM are combined in reconstruction schemes to automatically extract main technical standards of each scheme,and the technical and economical evaluation of each scheme was achieved,then the rationality assessment of each scheme from visual angle can be achieved based on the 3D cruise of each scheme.(3)Evaluation of reconstruction schemes based on dynamicsAnalysis and assessment of the safety and comfortableness of reconstruction scheme was conducted using vehicle-track integration model built via SIMPACK,the indexes involved insafety assessment including derailment coefficient,wheel unloading rate,both vertical and lateral wheel rail force,while in comfortableness evaluation,the indexes are vertical & lateral vibration acceleration,along with the economical & technical standards,the selection of reconstruction schemes can be realized.