波折钢腹板内衬混凝土组合梁力学性能与设计方法研究

The composite girders with corrugated steel webs have excellent properties, such as lightness, efficiency of introducing prestress forces, short construction period, optimum force distribution, good seismic performance, and aesthetics appearance etc., which have greatly promoted the application in bridge engineering. . A new type of partially encased composite I-girder with corrugated steel web has been proposed to improve the structural performance of continuous girders under hogging moment. The mechanical behaviors of such partially encased composite I-girders under shear and flexural loading have been experimentally and analytically investigated. The partially encased composite girders has superior shear and bending strength compared to steel I-girders, since shear bucking of steel web and local buckling of flange are restricted by concrete encasement. A three dimensional finite element model with material and contact nonlinearity is established and verified by the experiments. Subsequently, a parametric study is carried out to examine the effects of geometric and material properties on the mechanical behaviors which include corrugation, height, thickness, connection degree between steel web and concrete encasement. Finally, calculation models of stiffness and strength for partially encased composite girder with corrugated web are proposed. In addition, the predicted shear, bending strength and shear-bending interaction curve are compared with the experimental and numerical results to prove the accuracy and applicability of those proposed calculation models. All the findings including calculation models, design methods and curves from experimental, numerical and analytical studies may provide reference for design and construction of composite bridges with corrugated steel webs.

波折钢腹板组合梁以其优越的力学性能: 自重轻；预应力施加效率高；施工周期短；受力合理；良好的抗震性能等广泛应用于桥梁工程。 . 提出波折钢腹板内衬混凝土构造提高组合梁负弯矩区的结构性能。采用模型试验、理论分析、数值模拟相结合的方法系统研究波折腹板内衬混凝土组合梁的承载性能以及传力机理。由于钢腹板剪切屈曲以及翼缘局部屈曲受内衬混凝土约束，波折腹板组合梁剪切与弯曲承载性能大大提高。基于模型试验，建立考虑材料与接触非线性的实体有限元模型，分析研究波折腹板内衬混凝土梁几何与材料参数、以及波折腹板与内衬混凝土连接程度对承载性能的影响。最终提出建立波折钢腹板内衬混凝土组合结构的刚度与强度计算理论与设计方法，完善波折钢腹板组合桥梁设计理论与方法，为波折腹板组合结构桥梁在我国的应用与推广提供理论基础和依据。

通过提出波折钢腹板内衬混凝土构造提高组合梁负弯矩区的结构性能，改善抗剪、抗弯以及抗裂性能。采用模型试验、理论分析、数值模拟相结合的方法系统研究波折腹板内衬混凝土组合梁的承载性能以及传力机理。首先，对波折钢腹板与内衬混凝土之间的连接件进行系统研究，确保波折腹板与内衬混凝土之间相互作用、共同受力，提出了连接件抗剪刚度的计算方法以及改进的焊钉拉、剪相互作用强度曲线，并且建立了考虑拉力与峰值滑移影响的剪切刚度折减系数与荷载-滑移关系的合理表达式。其次，开展波折钢腹板内衬混凝土组合结构在剪力、弯矩以及弯剪耦合作用下的受力机理模型试验，并结合有限元与有限弹簧元数值模拟，以及经典的断裂力学和界面力学分析，提炼出波折钢腹板内衬混凝土组合结构的力学模型，明确了波折钢腹板与内衬混凝土承担荷载的比例及原则，探讨了波折钢腹板与内衬混凝土连接构造的传力机理，提出了波折钢腹板内衬混凝土组合梁抗剪、抗弯的刚度与强度理论计算模型，以及弯、剪共同作用的相关曲线，建立了波折钢腹板内衬混凝土组合梁的合理设计方法。最后，对波折钢腹板作为导梁进行先行架设施工的组合梁桥合理线形控制、考虑剪切变形影响的波折腹板组合梁动力特性分析、以及波形腹板与钢管混凝土板组合箱梁桥结构性能等方面进行系统、深入的研究，研究成果为波折腹板组合结构桥梁在我国的应用与推广提供理论基础和依据。