公路混合梁斜拉桥主梁钢混交界面合理位置分析

Analysis of Rational Position of Steel-concrete Interface in Main Girder of Highway Hybrid Girder Cable-stayed Bridge

摘要:

混合梁斜拉桥因其主梁充分发挥钢梁和混凝土梁各自的优势而应用广泛。主梁钢混交界面在主梁上位置的选取对斜拉桥的受力状态有重要影响，如何快速选取钢混交界面的位置成为斜拉桥方案设计中一个重要技术难点。基于斜拉索索面膜化的假定，推导了混合梁斜拉桥桥塔水平力之和与塔高、边中跨长度、混凝土和钢主梁恒载活载集度的关系，从斜拉桥合理成桥状态出发，由桥塔水平受力平衡得出混合梁斜拉桥的合理主梁钢混交界面位置的计算方法。并参考两篇混合梁斜拉桥文献的有限元计算分析结果验证了本方法的可行性和适用性。

Abstract:

The hybrid beam cable-stayed bridge is widely used for fully utilizing the advantages of steel girders and concrete girders. The range of the interface position between the steel girder and the concrete girder significantly affects the internal force distribution of the cable-stayed bridge. Determining this interface location expeditiously remains a crucial technical challenge to bridge conceptual design. Hypothesizing the dependent cables as a membrane model， the influence factors of the sum of horizontal component forces on the bridge tower are investigated， such as tower height， span length， live load and constant load of concrete and steel girders. Based on the rational dead load state of cable-stayed bridge and the horizontal force balance of bridge tower， the calculation methods for determining the optimal range of the interface position between the steel girder and the concrete girder are derived. The feasibility and applicability of the methods are confirmed by the finite element analysis results of hybrid girder cable-stayed bridges in two references.