Lateral Displacement Analysis And Optimum Of Outrigger-braced Frame-tube Structure

The resistance to lateral force system of high-rise building is the key to whether it is reasonable, secure and economical, which is needed to develop constantly in company with the structural height and the development demand of function. Major lateral displacement of frame-tube structure, which is a usual adopted structural system of high-rise structure, results from lateral rigidity shortage. Therefore, horizontal story with outriggers are usually located to satisfy the requirement of controlling the lateral displacement when designing. In this dissertation, a plane analytical model to horizontal outriggers-braced frame-tube structure and numerical analytic method are adopted to discuss the optimum number,the optimum locations, structural parameters effects and structural optimization after story of outriggers is located.Firstly, the dissertation introduced the action mechanism of the frame-tube structure when story with outriggers was located. Then we discussed the shortage of the current theoretical models, a more reasonable model and a relevant static analytic approach were presented , which were based on certain assumption. In this approach, it Simplify the floor beams into continuous medium, and also considered the bent and shear deformation of main members as well as the axis deformation of the frame-columns. Then structural deformation energy expression under the action of lateral load was found. By the minimum potential energy principle, the governing equilibrium equation of structure under lateral loads was set up. At last, combining variation principle with Rayleigh-Ritz method, lateral displacement expression of outriggers-braced frame-tube structure was solved out.Based on the structural lateral displacement expression, the optimum quantity of story with outriggers had been found according to a simple numerical analysis. Structural parameters effects to the top displacement and the optimum locations of story with outriggers were showed after changing the rigidity of each member while some ideas about structural parameters selection and structural optimization were suggested.