Study On Key Technology Of Several Gymnasiums

In this dissertation, key technology and some behaviors of three different gymnasiums were studied.The first was a reconstructing project of the cantilever roof structure. After preliminary calculating, some imperfections of the former design in this structure, such as weak stiffness, large horizontal force at both end supports and so on, were found. To each problem, some measures were taken to satisfy the codes through calculating and designing. Besides, this situation by considering the connection stiffness of the stand structure was analyzed, the results were shown that the carrying capacity of this structure was strengthened and the lateral stiffness of the concrete pillars were increased. Then the effects of the elastic stiffness of the supports to the roof were studied. Based on it, the nonlinear behaviors of this cantilever roof were studied, and found that this structure maintained good mechanics under all-area or semi-area loads. The dynamic response of the cantilever roof under seismic load also was analyzed by defining the coefficient of dynamic internal force of the truss. At last the dynamic stability under the seismic load and stepped load were discussed. Based on the present dynamic stability judging criterion,a new judging criterion was brought forward--the method of changing rate of stressand checked the feasibly.The second gymnasium was of the cable-stayed latticed structure, which composed of cables, members and concrete pillars. It was necessary to study the effects of these factors to this structure, such as the changing of the initial pre-stressed of cables, the error of the section area of trusses, and the weakening of the section area. In this chapter, orthogonal design method and Monte Carlo method were adopted to study the sensitivity of cables and trusses. Both the two methods could offer parameters to sort order the variables. The results were very significant for the design and construction. In additional, the results were also showed that the sensitivity conclusions of two methods were coincident.The length and width of the third gymnasium were 157m and 127m respectively. Four design projects were summarized out through considering steel weight, construction, rise-to-span ratio, joint form, and so on. Being compared with others, the spatialpipe-truss pre-stressed in bottom chord was considered more appropriate in this structure. Moreover, its working principal, the joint form and calculating method of sliding cables were discussed. As to calculating the sliding cable, tension distributing method and simulation method of short bar were adopted, which were compared with fixed cable. Finally some useful conclusions were summarized and the problems that should be studied further are put forward in the end of the article.