波形钢腹板体外预应力连续组合箱梁桥开裂扩展机制及失效过程研究

The prestressed composite continuous box-girder bridge with corrugated steel webs because of the advantages of light weight, good seismic performance, short construction period, lower cost, good durability, which has been widely used in foreign countries and caused the domestic engineering circles, but the domestic application was relatively small. At present, the domestic and foreign research achievement of prestressed composite box-girder bridge with corrugated steel webs were mostly based on simply supported box-girder, and the research on the mechanical behaviour and failure mechanism of prestressed composite continuous box-girder bridge with corrugated steel webs were lack. Through the research of this project,the mechanical properties and failure mechanism of prestressed composite continuous box-girder bridge with corrugated steel webs will be clearly knew, and the calculated model for external prestressing strand stress increment of prestressed composite continuous box-girder bridge with corrugated steel webs will be established, furthermore the calculate method of the moment modulation coefficient, the deflection considering second effect and the carrying capacity considering shear slip effect will be built. The research achievements of this project will be the important supplement and improvement on the theories of the prestressed composite continuous box-girder bridge with corrugated steel webs,and the new design calculation theory of this kind bridge will be provided simultaneously.

波形钢腹板体外预应力组合箱梁桥因具有自重轻、抗震性能好、施工工期短、成本低、耐久性好等优点，其在国外得到了广泛的应用并引起国内工程界的关注，但在国内应用相对较少。目前国内外对于波形钢腹板体外预应力组合箱梁桥的研究成果大部分都是基于简支梁得出的，缺乏对其连续结构受力行为和破坏机理的研究，即开裂扩展机制及失效过程的研究。本项目通过研究明确波形钢腹板体外预应力连续组合箱梁桥的开裂扩展机制及失效过程，建立适宜波形钢腹板体外预应力组合箱梁桥结构特点的体外预应力增量计算模型，提出弯矩调幅系数、考虑二次效应的挠度及考虑抗剪连接键界面剪切滑移效应的截面承载能力计算方法。本项目的研究成果将是对波形钢腹板体外预应力连续组合箱梁桥分析理论的重要补充和完善，同时也将为该类桥的设计计算提供新的理论依据。

摘要.本项目拟应用材料力学和结构力学的基本理论和方法，结合模型试验及数值仿真技术并根据波形钢腹板预应力组合箱梁本身的结构特点研究其受力行为和破坏机理，即其开裂扩展机制及失效过程，重点研究梁体裂缝扩展及失效过程的两大关键控制因素——体外预应力筋应力增量及内力重分布机制，建立适宜波形钢腹板体外预应力组合箱梁桥结构特点的体外预应力增量计算模型，提出弯矩调幅系数、考虑剪切变形的梁挠度及考虑抗剪连接键界面剪切滑移效应的截面承载能力计算方法。