波折钢腹板组合箱梁预应力体系研究

通过采用混合单元建立波折钢腹板预应力混凝土组合简支箱梁空间有限元计算模型,研究体内外混合配索结构的预应力参数,包括体内外索比例分配、张拉应力、锚固点位置以及转向装置的间距等对力学性能的影响。分析结果表明,跨中转向点之间各截面的正应力只与张拉力有关;而锚固点至转向点区域各截面的正应力随预应力参数变化,建议采用合理比例的体内外索混合配筋形式,张拉应力不宜小于标准抗拉强度的60%。为该新型结构体内外混合预应力设计提供参考。

Research on Internal and External Tendon System of Composite Box Girder Bridge with Corrugated Steel Webs

A 3D finite element model of an internal and external tendon concrete simple-supported composite box girder bridge with corrugated steel webs was established by means of the composite element method.The mechanical behaviors of the structure with different internal and external tendon parameters were analyzed,including the arrangement of the internal and external tendon,the tensile force,the position of the anchorage point and the distance of the diversion point.The conclusions show that the normal stresses of the sections between two diversion points in the mid-span only depend on the tensile force,while those between the anchorage point and the diversion point change with the parameters.The reasonable ratio of the external tendon and external tendon is suggested,and the prestressing force should be no less than 60% of characteristic value of tensile strength.The conclusions provide a reference for the design of internal and external tendons of composite box girder bridge with corrugated steel webs.