空间三撑杆双环索索穹顶考虑自重的预应力计算方法及参数分析

基于传统索穹顶构造形式的单一性和力学性能的不足，提出了一种空间三撑杆双环索索穹顶。提出了一种基于位移法与节点平衡法结合求解索、杆预应力的方法，并运用该方法计算比较了该索穹顶结构在是否考虑自重情况下预应力分布的差别；给出了索穹顶在考虑不同参数影响下的预应力计算表，对比了各种参数对结构性能的影响。结果表明：在考虑结构自重情况下，该索穹顶绝大部分索、杆预应力值都有不同程度的增大；撑杆高度与矢跨比的增大，会导致索穹顶结构中几乎所有构件的初始预应力值呈现减小的趋势，但增大撑杆高度相较于增大矢跨比影响更大。因此，在实际工程中，更多采用增大撑杆高度的方案。

CALCULATION METHOD AND PARAMETRIC ANALYSIS OF PRESTRESS DISTRIBUTION FOR CABLE DOMES WITH SPATIAL THREE-STRUTS AND DOUBLE-HOOP CABLES CONSIDERING THE SELF-WEIGHT

Based on the simplicity and the insufficiency of the mechanical properties of traditional cable domes, a spatial three-strut and double-hoop cable dome was proposed. A method for calculating the prestress of the struts and cables which integrated the displacement method and the nodal equilibrium method was proposed to calculate and compare the difference of prestress distribution of the cable domes under the conditions of considering self-weight or not. Calculation tables of the prestress were given and the influence of various parameters on the structural performance was compared under different parameters. The results showed that the prestress values for most members increased in various degrees when the self-weight was considered, that the increase of the strut height and span ratio would reduce the initial prestress of almost all the members in the cable dome, and that the increase of the strut height had more significant effects than that of the increase of the span ratio. Therefore, the scheme of increasing the strut height was more often adopted in engineering practice.