Research On The BIM-based Railway Construction Management Platform And Its Key Technologies

The railway construction management digitalization is the technical guarantee to achieve the full life cycle of railway construction,which holds the source data of railway engineering’s key properties.Because of some reasons such as time and technologies,the current railway digitalization has several problems of nonuniform interface standards,incomplete data structure,difficult multi-source heterogeneous data fusion,scarce unified integration platform,incontinuous information for whole process engineering,limited data management ability,nonuniform BIM application standards,insufficient application depth and scope,limited combination of BIM and new techniques,loose management and coordinating mechanism,inefficient collaboration,lacking thoughts of full lifecycle management,etc.It cannot satisfy the high standard requirements of the modern railway construction about reasonably shortening construction period,lowering construction cost,improving construction quality,and reducing construction risks.Therefore,it is necessary to launch the application value research on the BIM theory and its key technologies under the background of railway construction projects.Actively exploring the BIM-based railway construction management platform and a new mode of full lifecycle management would help to achieve the goal of full-range,total-factor,whole-process data sharing and utilizing for the railway construction,as well as meeting the requirements of full life cycle digitalized,refined,standardized management for the railway construction.There will be practical significance and application value to facilitate the development of intelligent construction and lean management for the railway engineering.The railway BIM technology and the BIM-based railway construction management are important supports currently for the railway intelligent construction to achieve high quality,high efficiency,lowering construction costs,and the full lifecycle management.In this thesis,treating the BIM-based full lifecycle management idea as the core,focusing on the railway construction management and practice,and learning from the advanced modern management idea and new technologies,a SOA+EA structural theory with the BIM model information flow as the mainline was proposed in this thesis.Having merged together all kinds of information from the railway construction,the thesis builds a BIM-based railway construction management platform,the EA model and the general architecture,and launch the research on some key technologies of the lightweighting for the railway construction data model,the inter-rendering visualized technology,the fusion technology of multi-source heterogeneous data,and the fusion application technology on BIM and new technologies(cloud computing,big data,IoT,etc.).In the end,it is taken into verification combined with the high-speed railway tunnel engineering practice after the development of the BIM-based railway construction management platform.The specific research contents and the innovation achievements are as below:(1)Based on the analysis of the research status of BIM and its development and application,railway BIM application technology,and railway construction digitalization,the BIM-based railway construction management intention are given.The fusion method of the modeling technologies of railway engineering data model,the interactive rendering visualization technology,the 3DGIS technology,and other new technologies(cloud computing,IoT,etc.)have been focused on research.(2)With the BIM model information flow as the mainline,having combined with all kinds of information in the railway construction,having utilized the object-oriented SOA+EA architecture,the EA model and the general architecture for the BIM-based railway construction management platform was designed.The general architecture includes the business architecture of BIM-based railway construction whole-process collaborative management,the multi-level application architecture based on construction management BIM application,project management BIM application,and monitoring management BIM application,the data architecture based on theme-oriented information model,the basic public data model and encoding and services,and the comprehensive business data management,and the technical architecture based on BIM infrastructure,3D digital technology,data management and application service technology.With the function modularization,the business flow integration,and the model data visualization,the inter-coordination and access between all kinds of front-end applications and the back-end services for the railway construction can be achieved,which can make the interconnection among the businesses,in-depth information integration,and the data fusion and sharing in the whole processes of railway construction management come true.(3)A comprehensive lightweighting method for the railway engineering information models based on element merging and edge folding was proposed to achieve the goal of model lightweighting without any application influences.The model layered dynamic loading and a mixed cloud graphics engine technology based on the combination of WebGL,ActiveX and cloud technologies was studied to achieve the on-demand dynamic model loading and effective interactive rendering for the web-based application access.The model lightweighting workflow was provided and the lightweighting plugins were also developed.With the graphics engine architecture designed,the model elements lightweighting transforming,attribute data high-effectively extracting and storing,and interactive visualized application can be achieved.In the end,the graphics rendering speed and precision can be enhanced and the users’ interactive experience can be improved,which is innovative indeed.(4)To meet the macroscopic,mesoscopic and microscopic management requirements of combining the railway construction information model and the large scene GIS information,after studying the multi-scale data fusion mechanism of model and GIS data,according to the technical idea of "modeling,transform,fusion,distribution,application",the multi-source heterogeneous model standard format and the transforming technology from the original vendor-defined format have been broke through.The multi-source heterogenous model data can consist of the landform data,oblique photogrammetry data,BIM model,etc.In details,the key technologies include the multi-scale multi-source heterogeneous data fusion,coordinates transforming between BIM and GIS,base matching,and the space-based semantic-considering BIM model data management technologies.The multi-layer comprehensive demonstrating applications were carried out based on the BIM+GIS multi-source heterogeneous database.Finally,the multi-source heterogeneous model data fusion for the railway construction and the application problems,which existed in integration,of bad model quality,missing semantic information,inconsistent coordinate system,non-uniform data format,and difficult data management,can be solved.(5)A BIM-based railway construction management platform was developed,completing the system architecture design,multi-source heterogeneous model data integration and fusion,and the typical application functions in the platform.An optimized overbreak-underbreak flatness evaluation algorithm for tunnel based on the fusion of BIM and 3D laser scanning techniques were innovatively proposed.By comprehensively using technologies of BIM,geologic advance prediction,surrounding rock monitoring,the tunnel safety dynamic measuring and monitoring was carried out to achieve BIM-based railway tunnel safety(safe interval,geologic advance prediction,surrounding rock monitoring)and quality(overbreak-underbreak flatness evaluation)digitalized integration management.Through providing the entity structure breaking method and the entity encoding specification for the high-speed railway large-diameter double-line shield tunnel engineering,with comprehensively utilizing the BIM+IOT.technologies,the real-time sensing,analyzing and early warning integration management for the BIM-based high-speed railway large-diameter shield tunnel can be achieved,which contains the quality management(segments producing,segments assembling,tunnel quality),safety and risk management(risk point automatically recognition,dynamic risk monitoring and evaluation),and progress management(tunnel construction visualized progress driven by the tunnel boring machine’s real-time data).In the end,the technologies and methods provided in this thesis were verified.