| Long-span spatial structure buildings can represent the architectural level of a country and are often the symbols of a city,which has important social significance.However,due to environmental corrosion and aging of materials during long-term service,structural performance may be degraded,which may cause safety hazards in the structure.Structural health monitoring can eliminate potential safety hazards of structures,predict structural performance changes,which could reduce the occurrence of engineering accidents and the result loss of life and property.Taking the key project of Qingdao Jiaodong International Airport Terminal as the background,this paper studies the long-term health monitoring of the structure,This paper proposes a method based on cuckoo search algorithm to improve the support vector machine to process the missing data in the later monitoring.This method is verified in the data processing of the steel roof structure health monitoring in the main stadium of Shenzhen Universiade.The main contents are as follows:(1)This paper discusses the importance and necessity of structural health monitoring,introduces the development status and history of health monitoring systems at home and abroad,points out the existing problems and deficiencies in the current research,explains the importance of data missing research for safety assessment,puts forward several repair methods,and expounds their basic principles and advantages and disadvantages.(2)This paper introduces the research object of Qingdao Jiaodong International Airport terminal in detail,and explains its structural layout in detail.The self-developed health monitoring system is composed of sensor system,data acquisition and transmission system,data processing and control system,safety evaluation system and safety early warning system.Each subsystem has a clear division of labor and is interdependent.Together,it carries out long-term health monitoring on structural member stress,structural vertical displacement,support horizontal displacement and overall vibration,thus fully ensuring structural safety.(3)According to the 3D3 S model of terminal steel grid made by China Southwest Architecture design and research institute provided by the airport,the finite element model of Qingdao Jiaodong International Airport terminal steel grid structure was reestablished.The parameter setting and load distribution of the models are introduced.The stress,displacement and vibration mode frequency of members in the structure under the limit state of bearing capacity are analyzed.The finite element analysis results of the two softwares are compared,and the best measuring point arrangement scheme is determined based on the comparison.In addition,when monitoring is started,the structure is in a nearly completed state,so it is necessary to determine the initial state of the structure.By using reverse thinking,the applied load on the current structure can be subtracted item by item to obtain the initial state of the structure.Through analysis,this method has higher reliability.(4)This paper introduces the support vector machine algorithm,the significance of important parameters,the existing problems and improvement ideas,proposes to optimize the important parameters of support vector machine with cuckoo search,explains them in detail,and applies them to the interpolation and reconstruction of missing data.The data from the health monitoring of the steel roof structure of the main stadium of Shenzhen Universiade are verified and compared with the linear regression of single measuring point,the linear regression of multiple measuring points and the regression of traditional support vector machine.The results show that the cuckoo’s improved support vector machine repair ability is better than that of linear regression and traditional support vector machine regression in a small range of data repair.This method can greatly reduce the workload and calculation during data repair,ensure the accuracy of reconstructed data,and meet the requirements of evaluation index and engineering accuracy. |
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