Experimental Study And Theoretical Analysis Of Steel Truss Transfer Story With Large Span In Tall Buildings

Currently, along with the quick development of tall buildings, the requests to architectural function become more and more complicated. Due to good performance while suffering static and seismic loading, steel structure is extensively used in civil engineering. For transfer member with large span, it is a kind of good choice to adopt a steel structure. Because of large span, the steel truss transfer member in a tall building will get a huge load effect with a vertical loading. Furthermore, there are many factors on load effect of steel truss, especially temperature function and the constraints at truss end.Studies concerning to steel truss transfer member with large span, have not been reported yet. It is the first time to set up the research to load effect factors of steel truss transfer member, stage construction methods, and seismic performance by the means of test research and theories analysis.First, the load effect influence factor to the steel truss transfer story, including temperature load effect and differential constrains at the truss end, relative stiffness change between the transfer story with its upper frame structure, and relative stiffness change between transfer story and its lower frame structure, is studied. At the mean time, discussion about selecting the transfer story's number of upper and lower floor in local analysis is performed. Based on the study, some advices to the staged construction project are suggested.Next, the simulation experiment of the whole staged construction process of the steel truss transfer story is conducted. In staged construction process, study is primarily aimed at the truss load resistance capacity and flexural performance under construction and design load, combination performances of steel trusses in conjunction with concrete beam, the vertical displacement difference of two steel trusses with different span and their lateral stability, the glide displacement of the steel truss end during construction, the load resistance performance of steel trusses and concrete structure at the designed load, and the extreme limit loads and thebreaking appearance of the combined steel trusses.According to the whole model experiments process, the theoretical model is constructed and analyzed. Theoretically, studies are primarily on steel trusses combination in conjunction with concrete beam, the vertical displacement difference of two steel trusses with different span and their lateral stability, etc. And the loading resistance performance of the steel truss and concrete structure are studied in staged construction process and non-staged process. With the experiment's result and theoretical studying result, the discussion about character of staged construction is performed. Some problems and solutions in staged construction are put forward. In tall buildings, for frame-shearwall structure with steel truss transfer story with large span, studies on its dynamic characters and seismic performance are performed. With different transfer story location at the structure, the difference analysis about the structures to period and mode, displacement, and shear etc. is performed in detail. And the vertical load effect to the steel truss transfer story with large span is analyzed.Finally, according to research results, some suggestions to the design and construction of steel truss transfer story are put forward.