Digitization Research On Maintenance And Management System Of Long-Span Cable-Stayed Bridges

Along with the design trend of pliability, complication and bridge accidents related to safety happening continually, governments of many countries have paid more attention to bridge security. Till now, although some achievements have been attained on management system of long-span bridges, this subject is still at the exploring level and there are still many key problems unsolved, because maintenance and management system of long-span bridges is a complicated systematic engineering. Based on this background, some problems of maintenance and management system of long-span cable-stayed bridges are researched in this thesis.First, summarize and appraise the present status of research and application of domestic and foreign bridge management system of long-span bridges, some questions of bridge management system in existence is proposed. Then, a collectivity frame of digitization maintenance and management system of long-span cable-stayed bridge is designed. In the system, the thought of combine bridge health monitoring data with bridge management system is proposed, and the conception of initiative maintenance of cable-stayed bridges is introduced, and then the integrity inspection system and assessment system are established.Based on uncertain type of AHP, a suit of integrity and applied theory system of comprehensive assessment of long-span cable-stayed bridges is established. The thorough research of the theories which including assessment indices choice, degree choice, judgment matrix formation, consistency checkout of interval number judgment matrix, calculation method choice of interval number judgment matrix, calculation of experts impersonality weights, synthesization of indices weights and application of variable weight theory is done. The feasibility and practicability of the theories are proved by an instance. Besides, based on fuzzy assessment theory, a fuzzy comprehensive assessment method is established, which is applicable to comprehensive assessment of long-span cable-stayed bridges. The profound study is carried out on assessment grade determination, establishment of subordinate function and composite operator choice. The simultaneous use of the two assessment methods would ensure the objectivity and scientificity of comprehensive assessment results.All the indices of comprehensive assessment can be divided into qualitative indices and quantitative indices. The method which makes qualitative indices quantitative and meticulous is studied. Then, three types of'six-point'models are established,which include positive indices model, negative indices model and moderation indices model. The scientificity and practicability of'six-point'method are proved by three instances.A disease diagnosis database and a maintenance decision-making database of cable-stayed bridges are established, which are applied to Digitization Maintenance and Management System of Harbin Sifangtai Cable-stayed Bridge. The database could provide important references of disease recognition and maintenance decision-making for maintenance personnel. The durability theory and aging analysis theory are used to predict the long-term performance of cable-stayed bridges, and the results could provide quantitive reference for bridge management department. Besides, bearing capacity theory based on criterion is studied, and the variable weight theory is applied.Digitization Maintenance and Management System of Harbin Sifangtai Cable-stayed Bridge, which called DMMS, is programmed with SQL Server 2000 and Visual studio.net 2003. DMMS establishes an integrative maintenance and management system for long-span cable-stayed bridges. Based on the data from Manual Inspection Database, Bridge Basic Database and Health Monitoring Subsystem, this system could accomplish the functions such as disease diagnosis, structural pre-warning, life prediction, maintenance and management by updating spatial FE models. DMMS adopts two sets of comprehensive assessment methods and bearing capacity assessment methods to evaluate the state of bridge scientifically. In addition, the system establishes an integrated database of maintenances and diseases for cable-stayed bridges, and provides more comprehensive Maintenance and Management Directory and Experiment Methods Manual. Therefore, the system provides detailed technical instruction for long-span cable-stayed bridges and assistant instrument to ensure the safe service of bridges.