Research And Application Of Cantilever Expansion Construction Technology Of Frame

The steel space frame of Qingdao broadcast and TV building stage is a flat steelroof. The structure form of the flat steel roof is a rack with a weight of68ton which hasfour spans and has3gridding in each span. The steel rack has a span of28-metre fromeast to west and30-metre from north to south.The reticulated shell of Chinese Marine University comprehensive gymnasium is acomplex long span multi-surface shaped steel roof, which is a hyperbolic paraboloidsteel frame. The area of the rack is6600square meters. The height of the roof is35-metre.Considering the structural form of these two roofs and the difference ofconstruction circumstance, and basing on the previous work, we take the advantage ofANSYS to analyze the construction technology according to the practical situation ofengineering, We propose the method of bar support cantilever expansion.The main content of this paper include:1) The stability factor of starting element. According to the two practicalengineering, we use ANSYS to analyze the stability factor of starting element. The mainresearch contents include the effect on stability of the units by supporting frame belowstarting elements and changes of defection and stress before and after removingsupporting frame during the construction process.2) determine the construction sequence of cantilever extended spell of steel rack byfinite element analysis software ANSYS. First lift small spelled units by small lifthoisting equipment, then assemble from middle to both sides or in the opposite directionthrough the artificial. This paper analyzes the feasibility, variation of defection andstress of the above two different methods, and determine the optimal constructionsequence after comprehensive comparison.3) Contraposing the related issues of dismantling bar support in advance when flatsteel rack and hyperbolic paraboloid steel structure are assembled, combining stagehall in Qingdao radio and television building and nets shell project of comprehensivegymnasium in Ocean University of China, and then through construction simulation analysis and engineering practice research of the two different forms of steel framestructure, this paper proposes conditions of cancelling bar supporting frame and formingstable band starting units and forms cantilever extension assembling constructiontechnology of rack band starting units during which bar supporting frame can bedismantled in advance.