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预应力混凝土部分斜拉桥的整体钢绞线用量由斜拉索与体内预应力钢筋两部分组成,两者用量直接影响结构整体受力。该文基于两者对截面预压应力的计算公式,采用Midas/Civil建立全桥有限元模型,控制斜拉索及预应力钢筋的初始张拉应力,通过改变两者的面积控制两者用量,分析两者的用量比例对结构受力性能的影响。计算结果表明:部分斜拉桥索、筋比值越大,跨中在恒载、活载及时变效应下的变形值越小,对应拉索应力幅值越小;但预应力所占比例过小时,跨中在恒载作用下即会出现拉应力。当索、筋分配比值为1.22左右时主梁压应力储备最为安全且变形值均满足规范要求。
The amount of the whole steel strand of the prestressed concrete partial cable-stayed bridge is composed of two parts of the stay cables and the prestressed steel bars in the body, and the amount of both directly affects the overall force of the structure. Based on the formula of prestressing stress of the two sections, Midas / Civil is used to establish the full-bridge finite element model to control the initial tensile stress of stay cables and prestressing rebar. The amount of both are controlled by changing the area of both. Analysis of the proportion of the two effects on the performance of the structure. The calculation results show that the smaller the deformation value of the midline under constant load, live load and time-varying effect, the smaller the corresponding stress amplitude of the cable; while the proportion of prestressed cable is too small , Cross in the role of dead load that will appear tensile stress. When the rope and tendon distribution ratio is about 1.22, the main girder compressive stress reserve is the safest and the deformation values meet the specifications.