Ring Beam String Structure Ultimate Bearing Capacity And Reliability Analysis Of Considering Construction Error

Large span ring beam string structure is an important part of the public building,and plays a very important role. Because of its diverse forms, complex construction process and easily affect by environmental temperature, etc., so that it is susceptible of various errors. This thesis analyzed the performances of overall stability and reliability of the large span ring beam string structure considering the effect of construction errors.There are less research of large span ring beam string structure in construction errors in the current, taking the roof of Wuwei stadium large span ring beam string structure as an research object, using the SAP2000 to create the FEM. Firstly,According to the date of measured structure response, the structure finite element model was updated with the improved response surface method, then the benchmark model was created. Then analyzed the static and dynamic characters of the structure and simulated of measured construction error, under construction error, the structure performances of overall stability was analyzed, and the structure curve of load-displacement was drawn. Lastly, reliability performances of large span ring prestressed beam string structure was analyzed with the response surface method under displacement control failure modes. The main research contents and conclusions can be drawn as follows:(1) According to the content of health monitoring scheme, the displacement、cable tension、strain、stress and temperature of Wuwei stadium large span ring beam string structure were monitored. The monitoring result shows that main construction errors are strut inclined and the cables of super or owe tension.(2) Based on the measured displacement and cable tension, the improved response surface method is applied to update a large span annular string structural finite element model. Amended structure response deviation decreases about 20% on average, and the structural displacement deviation control less than 10%, cable tension deviation control less than 5%. Indicating that the relationship between the actual structural response and the parameters was well expressed by the response surface model, so the modified model can be used as a benchmark model.(3) Static analysis, dynamic analysis, time history analysis, IDA and fragility analysis were made for the benchmark model; Static bearing performance analysisshows that the structural stresses and cable tension is less than the allowable value,structure have a greater vertical displacement; Dynamic characteristics analysis shows that the structural short axial stiffness weaker than length axial and the vertical stiffness is weakest; Four different combinations of response spectra analysis shows that, although the seismic force is not control action, the structure is more sensitive to the vertical earthquake action; Time history analysis is compared with spectra analysis shows that the former has larger internal force, and the structural analysis under ground motion is closer to the actual structure; IDA and structural fragility analysis shows that the structural stiffness effect of the outer ring stays inclined is slightly larger than the inner strut inclined, the construction error of strut inclined is limited for the structural stiffness effect, and the construction error of prestressed is relatively large for the structural stiffness effect; Regardless of what construction errors exists, structure requires intensive earthquake action to damage.(4) Considered separately strut inclination 5%,10%,15% and the cables of super or owe tension, the structural analysis of linear and non-linear overall stability shows that stable factors can met the requirements of code. When the number of inclined struts reaches a total of about 3/4, stability factor is minimum. The stability under half span load is lower than full span load, cable tension and full span load is better than other favorable conditions for structural stability, but in terms of the variation of stability factor, structural stability is less sensitive to struts inclined and ultra-tensioned cables.(5) Using the response surface method to calculate the structural reliability of displacement control failure modes under the strut inclination of 5%, 10%, 15% and the cables of super or owe tension. When the number of structure inclined struts increase, the structural reliability at first is decrease and then increase, the impact of structural reliability outer strut inclination is greater than the inner pole, the super or owe tension cable have a certain impact on the reliability, but the structure remains safe.