钢锚梁-钢牛腿组合索塔锚固结构混合剪力连接件受力特性研究

STUDY OF BEHAVIORS OF MIXED SHEAR CONNECTORS FOR CABLE-PYLON COMPOSITE ANCHOR STRUCTURE WITH STEEL ANCHOR BEAM AND STEEL CORBEL

鉴于混合剪力连接件受力特性的复杂性,以厦漳跨海大桥北汊主桥为工程背景,在模型试验研究的基础上,采用壳-梁-实体精细化有限元数值方法对钢锚梁-钢牛腿组合索塔锚固结构混合剪力连接件受力状态、传力机理及其影响因素进行研究。结果表明:焊钉群竖向剪力横桥向上整体呈现边缘大、中间小的分布趋势;竖向上牛腿顶板以上钉群竖向剪力自上向下逐渐增加,顶板以下区域呈马鞍形分布。焊钉群较大轴向拉力出现在牛腿顶板对应位置,较大轴向压力出现在牛腿腹板高度对应位置。PBL剪力键群承担的竖向力和水平力均表现出中间大、边缘小的分布规律。混凝土塔壁承压、竖向力的变化以及面外弯矩的作用,对索力竖向分力在混合剪力连接件间分配的影响依次增大。

Because of the complexity of the mechanical features of mixed shear connectors,mechanical behaviors of the shear connectors in cable-pylon composite anchor structure with steel anchor beam and steel corbel were studied in the backdrop of the northern branch bridge of Xiazhang Bay Bridge through the finite element analysis（ FEA） and model test. The results showed that the shear force of studs for the outer column was larger than that of the middle. In the areas of the above of corbel roof,the shear force of studs for the top was less than that of the bottom. And in areas of below of corbel roof,the shear force distribution of the studs was like the shape of a saddle. The studs at the corresponding position of corbel＇s roof had the larger axial tension,and there was the larger axial pressure in the studs at the corresponding position of corbel＇s web. The vertical force and the horizontal force carried by PBL shear connectors in the middle column were larger than those of the outer one. The influence degree of the vertical pressure of the concrete pylon,the change in vertical force and the role of out-plane bending moment for the ratio of the shear force on the distribution of the vertical component of the cable force distributed between the mixed shear connectors was increased gradually.