大跨度铁路钢箱梁斜拉桥对接式锚拉板受力及传力特性研究

Forces and Their Transmission Characteristics of Butt-Type Tensile Anchor Plate of Long-Span Railway Cable-Stayed Bridge with Steel Box Girder

针对新型大跨度铁路钢箱梁斜拉桥对接式锚拉板,采用仿真分析与室内足尺模型试验相结合的研究方法,研究原结构在最不利索力下的受力传力特性,并分析不同设计参数对结构受力传力的影响。结果表明:斜拉桥对接式锚拉板主要传力板件为锚筒、锚筒加劲肋和锚板;锚板与锚筒连接焊缝及锚板与腹板对接焊缝是关键传力部位;仅在锚板开孔圆弧过渡处、锚筒及其加劲肋与承压板相接处、锚板与锚筒连接焊缝端点、承压板与锚板焊缝端点存在小范围应力集中,结构整体应力水平在150 MPa以内;试验实测与理论应力结果吻合较好;随着锚筒与锚板焊缝长度缩短,焊缝应力分布曲线整体向高应力区移动,且低应力区段应力增长幅度大于高应力区段;随锚板厚度的增加,锚筒与锚板焊缝整体应力呈现显著降低的趋势,但应力降低的速率随锚板厚度增加而降低;锚拉板结构具有良好的受力传力性能。

Aiming at the new type of butt-type tensile anchor plate for long-span railway cable-stayed bridge, the force transmission characteristics of the original bridge structure under the most unfavorable cable force were studied by means of simulation analysis and full-scale model test in laboratory, and the influence of different design parameters on the force transmission of the structure was analyzed. Results show that the main force transferring plates for the butt-type tensile anchor plate of cable-stayed bridge are anchor pipe, anchor pipe rib and anchor plate. The joint weld between the anchor plate and anchor pipe as well as the butt weld between the anchor plate and web are the key force transferring parts. There is only a small range of stress concentration at the arc transition of the anchor plate opening, the connection between the anchor pipe, anchor pipe rib and bearing plate, the end point of the joint weld between anchor plate and anchor pipe, and the end point of the joint weld between the bearing plate and the anchor plate. The overall stress level of the structure is less than 150 MPa, and the experimental results are in good agreement with the theoretical stress results. With the shortening of the weld length between the anchor pipe and the anchor plate, the stress distribution curve of the weld moves towards the high stress area as a whole, and the stress increase amplitude in the low stress section is higher than that in the high stress section. With the increase of the thickness of the anchor plate, the overall stress of the weld between the anchor pipe and the anchor plate decreases significantly, but the rate of stress reduction decreases with the increase of the thickness of the anchor plate. The tensile anchor plate structure has good force transmission performance.