拱形钢管桁架结构榀间距优化分析

Optimal analysis of spacing between arched steel tube truss structures

拱形钢管桁架结构在封闭煤场中得到广泛的运用,为研究主桁架榀间距对结构经济性的影响规律。对大跨度拱形钢管桁架整体结构进行简化,将简化结构的位移和整体结构的位移进行比较,依据对比的结果对简化结构进行主桁架榀间距分析,按照应力比优化为算法准则,计算不同主桁架榀间距结构的最大竖向位移、支座反力和单位面积用钢量。研究结果表明:以三榀主桁架组成的简化结构和整体结构最大竖向位移差值未超过3.0%,相差较小,说明简化结构和整体结构的受力特点比较一致。结构最大竖向位移和最大支座反力随着主桁架榀间距的增加而增大,主桁架榀间距为28.7m单位用钢量最少,经济性最高,主桁架榀间距在20~25.8m经济性一般,超过34.5m或小于17.1m的榀间距经济性差,在实际工程设计中应该合理选择主桁架榀间距。

Arched steel tube truss structure is widely used in closed coal yard,in order to study the influence of main truss spacing on structure economy.The overall structure of long-span arch steel tube truss is simplified.The displacement of the simplified structure and the displacement of the overall structure are compared.Based on the comparison results,the spacing of the main truss of the simplified structure is analyzed.According to the stress ratio optimization as the algorithm criterion,the maximum vertical displacement,bearing reaction force and steel consumption per unit area of different main truss spacing structures are calculated.The results show that the maximum vertical displacement difference between the simplified structure and the overall structure composed of three main trusses does not exceed 3.0%,and the difference is small,indicating that the stress characteristics of the simplified structure and the overall structure are relatively consistent.The maximum vertical displacement and maximum bearing reaction force of the structure increase with the increase of the spacing of the main truss.The steel consumption per unit of the main truss spacing of 28.7m is the least,and the economy is the highest.The economy of the main truss spacing in 20~25.8m is general,and the economy of the spacing of more than 34.5m or less than 17.1m is poor.The spacing of the main truss should be reasonably selected in the actual engineering design.