预应力超静定结构的等效荷载计算

预应力对超静定结构的作用,除产生主弯矩外还产生次弯矩。等效荷载法是计算次弯矩的最简便方法,但现有等效荷载的计算公式是通过预应力沿预应力筋不变的静定梁求得的,而在实际结构中,尤其是在多跨曲线配筋的预应力超静定结构中,预应力沿预应力筋有明显的变化,因而按现有方法计算等效荷载存在较大的误差。本文提出预应力沿预应力筋变化的超静定结构的等效荷载计算方法,以供设计应用。文末并附有计算实例。

Calculation of Equivalent Loads in Statically Indeterminate Prestressed Concrete Structures

In addition to primary moments, secondary moments will also be introduced in prestressing of statically indeterminate pre-stressed concrete structures. The simplest method for computing such secondary moments is the Equivalent Loads Method. However, the formulas available are based on statically determinate structures with constant prestress along the tendons. While in practice, especially in multispan statically indeterminate structures, the prestress are varying appreciable along the tendons. In this case a considerable error lies in the results computed from the conventional method. In this paper, a computing method of equivalent loads in statically indeterminate structures with varying prestress along the tendons is presented.