Cable-stayed bridge design itself has a sense of rhythm, and the special-shaped bridge tower structure can be used to make its aesthetic attributes outstanding, but the use of special-shaped bridge towers often makes the stress state more complicated, and the results are not universal, and targeted research needs to be carried out. Based on the Dongping River Bridge project where the main bridge is a special-shaped cable-stayed bridge, this paper analyzes two types of stability problems of the herringbone rigid frame and diagonal brace tower structure, and considers the influence of different cable forces. The results show that for such special-shaped bridge towers, the use of the first type of stability analysis may lead to a great overestimation of the stability safety factor, and the true instability mode cannot be obtained. The instability of the special-shaped bridge tower structure is significantly affected by the nonlinear factors of the material, and increasing the cable force will make the local structure more prone to plastic deformation, resulting in a significant reduction in the second type of stability safety factor.

上海嘉定惠平路桥主桥由于建筑景观要求很高而采用针形独塔斜拉桥方案。斜拉桥结构主梁和主墩固结，墩梁节点构造设计复杂，借助3D空间有限元了解节点区域内荷载作用下的应力分布情况。利用结构分析软件ANSYS，建立符合圣维南原理并被验证有效的节点分析仿真模型；利用仿真模型，分析得到该节点区域的钢箱梁节段与固结区内钢结构应力，主墩混凝土的应力与裂缝宽度，为有关节点结构设计提供意见与建议。

Aiming at the calculation example of a prestressed concrete ramp curved girder bridge,the internal force contrast of the straight line and the curved girder bridges has been done.When the ramp curved radius is greater than or equal to 40 m,the result precision can meet the design requirements totally according to the straight line girder bridge.And the calculation way should provide convenience for the design.