Experimental Study And Theoretical Analysis Of Long Span Higher-level Steel Truss Transfer Story Structure

Higher-level long span steel truss transfer story structure is a new kind of structure type. Some theoretical and experimental studies have been carried out by scholars at home and abroad. In this paper, field test of the higher-level long span steel truss transfer story of Zhejiang electric power attempter building were carried out throughout the whole construction progress and the test result was compared with the 1:7.5 scaled model experiment done by China architecture and building research institute. The influence on the load of the transfer story caused by ground unequal settlement and temperature difference caused by sunlight was also analyzed theoretically. At last, the vertical elastic seismic response and the vertical static elastic-plastic analyze were performed.The results of field measurement and model experiment shown that there have a mount of friction force on the end of steel truss and the supporting surface, which confines the slipping of the steel truss. The horizontal displacement on the end of steel truss by the temperature changing is smaller. The stress level of steel truss is lower, and stress level of end chord is smaller than that of the mid-span chord and end web member.The stress influence of ground unequal settlement on the transfer structure was calculated according two kinds of analysis models. The results indicated that effect is not obviously. Base of the temperature distribution of the transfer structure on the field measurement, difference of temperature caused by sunlight was analyzed, then the calculated results are compared with the actual measurement stress, which indicated that the temperature effect is significant.Some vertical seismic analysis methods of large-span steel truss transfer structures were investigated, which include that choice of mode assembly and determined of mode number in the response spectra method. Then internal force distribution of transfer structure under vertical earthquake is computed.Through Push-over analysis, the produce order and the mechanism of the plastic hinges for transfer structures are disclosed. By capacity spectrum method, the seismic capacity of frame-shear wall structure was evaluated. The results show that Zhejiang electric power attempter building can resist vertical seismic action one intensity degree higher than horizontal seismic action. The seismic resistance design of the structure is quite reasonable and it has a quite large safety reserve.