Development And Application Of An BIM-based Metro Protection System

It has become a common phenomenon that a large number of new construction projects are launched around the metro structure along with the acceleration of the urbanization process in China.When these surrounding external projects launched relevant civil construction activities,they will inevitably affect the safety and normal operation of the metro structure.Therefore,it is necessary to evaluate the influence on the metro structure before and during the construction of the external project to ensure the safety of the metro,and control the potential safety risks in time.‘Metro protection' is exactly the task of evaluating,detecting,and controlling the potential threats presented by external projects to metro structures,Metro protection work concerns the interaction between existing metro structures and external project structures.Multi-participants,complexity of models and mass information are the three major characteristics of metro protection work.These characteristics have led to handicaps in the current metro protection work such as isolation of models,difficulties in information extraction,and the lack of data processing and analysis methods.The ‘information isolation' is the root of various barriers in metro protection work,which leads to inconvenience in information exchange.BIM(Building Information Model/Modeling)is a new technology that aims to solve the long-standing “information isolation” phenomenon in the entire life cycle of architecture.After investigating the requirements and demands,this study introduced BIM technology into metro protection.In the information storage aspect,this study proposed the Metro Protection Information Model(MPIM)based on Industry Foundation Classes(IFC),the general international standard for BIM information exchange.MPIM has expanded the original IFC by defining multiple shared-layer entities and corresponding property sets and enumerated types based on the domain features of the metro protection,thereby enabling more accurate and specific information expression.In information integration aspect,the information integration methods based on BIM are studied,including the integration method between IFC model and non IFC model,the integration method of monitoring information,monitoring equipment and BIM model based on WebApi.The integration further improves the MPIM information model.In information application aspect,taking MPIM as a data source and aiming at the main work flow in metro protection,an automatic reviewing algorithm based on information extraction and classification,and an evaluation algorithm to quantitatively assess the priority and urgency based on analytic hierarchy process and neural network are proposed to realize computer-aided evaluation and decision-making in the work process of metro protection.Finally,a BIM-based Metro Protection System(BIM-MPS)was developed based on the existing BIM-FIM of the research group,.BIM-MPS was applied to the the metro protection work in the section between the Modiesha station and Xingangdong of the Guangzhou Metro Line 8 to verify the actual results and effects of the model and algorithm proposed in this study.After trial,the BIM-MPS system proposed by this research has obtained the affirmative feedback from the relevant users.Managers claim that the system saves more than 40% of the evaluation time,the quantitative evaluation of different external projects can reduce 80% of the time cost.Trial has achieved good results and also provided reference and experience for further application of BIM technology in metro protection.