Health Monitoring And Early Warning For Ancient Timber Structure Based On BIM Technology

Health monitoring of ancient wooden structures and timely warning of abnormal events and structural deterioration are key technical means of preventive protection,which is of great significance to ensure the survival of architectural heritage.However,most of the established systems have problems such as huge and complicated data,difficult alarm location,slow warning response and low level of visualization.Building Information Modeling(BIM)technology has good advantages in multi-source information integration and visualization,which can solve the above problems well.In this thesis,the BIM-based structural health monitoring technology is used to systematically study the multi-dimensional BIM model establishment,multi-source information integration,structural early warning mechanism,multi-functional management platform development and other contents,taking the Feiyun Wooden Pavilion as the typical ancient wooden building,to achieve its preventive protection.The main research contents and achievements are as follows:(1)The parameterized multidimensional model of ancient wooden structure is established,and multi-source information integration is realized.This thesis analyzes the structural construction of ancient building of the Feiyun Wooden Pavilion and realizes the parametric establishment of BIM model of components of the Feiyun Wooden Pavilion by using the parameterization function of Revit software.Based on this,the multi-dimensional BIM model integrating "structure-repair-monitoring" of the Feiyun Wooden Pavilion is established,and the integration of multi-source information of ancient wooden structure into the BIM model is realized.At the same time,SQL Server database was designed and constructed to assist in the integration of large volume multi-source information of ancient wooden structure.(2)A dual-index early-warning mechanism suitable for long-term static monitoring of ancient wooden structures is proposed,and the code implementation and example verification are carried out.Based on the existing monitoring data of the wooden structure of ancient buildings,two indexes,the daily average monitoring value and the daily average change rate,are selected to propose a statistical method for setting early warning thresholds.A three-level early-warning mechanism is proposed using dual indexes,and corresponding processing measures were set according to the warning results.Based on the existing data of database and T-SQL language,the setting of early warning threshold and simulation application of structure early warning are realized,and the effectiveness of the early warning mechanism is verified.(3)Developed the information integration and monitoring early warning platform of ancient wooden structure.Using Revit secondary development and SQL Server database development technology,the BIM platform with two preventive protection functions of information integration,and structure monitoring and early warning is realized.Platform were set up user login management,structural information management,structural early warning management,information interaction management four modules,which can realize huge body multi-source information integration and associated query between diagrams and 3D visualization,custom quick settings of early warning threshold for structural monitoring,structural early warning using dual-index early warning mechanism and associated query the results,and other functions.The application of the platform to the actual ancient building—the Feiyun Wooden Pavilion improves the efficiency and visualization of multi-source information query,and significantly improves the structural operation and maintenance management level.(4)Based on the case of structural response monitoring and early warning,the application effect of structural early warning mechanism and the processing and analysis of early warning result of ancient wooden structure are given.The ideas of processing the result of structural early warning and backtracking analysis of influencing factors are put forward.Temperature,the main factor affecting the strain response of wood structure,is quantitatively analyzed by finite element method,and it is found that temperature has different effects on different components of the Feiyun Wooden Pavilion.Then two sections of actual monitoring data of the Feiyun Wooden Pavilion are selected as early-warning trigger cases for analysis.The results show that:temperature is the main factor to trigger the early warning of the structure;humidity can be the main factor of trigger early warning for some beam members,and its influence has delayed effect;a small number of people visiting the building for a short time has no obvious influence on the structure;there are some problematic components screened out according to the warning frequency in the structure of the Feiyun Wooden Pavilion,which need to be paid attention to in the follow-up monitoring.There are 129 figures,33 tables and 122 references in this thesis.