斜拉悬索协作体系桥梁塔-基钢混结合段受力分析

Analysis on Force of Bridge Pylon - Foundation Steel - Concrete Combined Segment of Stayed Suspension Cable Cooperative System

摘要:

为了解斜拉-悬索协作体系桥梁塔-基钢混结合段受力情况，根据某实际工程，利用ANSYS软件建立塔-基钢混结合段的三维实体有限元模型，分析计算其在最不利荷载工况下的力学特性。结果表明：运营阶段的作用效应组合工况为塔-基钢混结合段受力最不利荷载工况；塔-基钢混结合段的钢箱部分受力呈近承台面应力水平低、近结合段上分界面应力水平高的分布规律，钢箱部分最大Mises应力小于材料屈服强度；主桥塔钢箱内填混凝土在钢混结合段上分界面处及与承台顶面交界面因尺寸突变均出现小范围点状拉应力集中，峰值达8.5 MPa；最大主压应力为16.8 MPa，均小于规范限值。在不考虑极少位置应力集中开裂的情况下，塔-基钢混结合段受力安全。

Abstract:

In order to understand the force of the bridge pylon - foundation steel-concrete combined segment of stayed suspension cable cooperative system, according to a practical project, a three-dimensional solid finite element model of the pylon-foundation steel-concrete combined segment is established by ANSYS software to analyze and calculate its mechanical characteristics under the most unfavorable load conditions. The results show that the action effect combination in the operation stage is the most unfavorable load condition of the pylon - foundation steel-concrete combined segment. The stress of steel box in the steel-concrete combined segment of the pylon and foundation presents the distribution law that stress level near the base slab surface is low and the stress level near the interface on the combined segment is high. The maximum Mises stress of the steel box is less than the yield strength of material. A small area of point-like tensile stress concentration appears at the interface on the steel-concrete combined segment and at the interface on the top surface of the base slab when the concrete is filled into the steel box of the main bridge pylon due to the sudden change of size. The peak value reaches 8.5 MPa, and the maximum principal compressive stress is 16.8mpa, which are all less than the specification limit. Under the condition of not considering the stress concentration cracking at the minimum positions, the force at the pylon - foundation steel - concrete combined segment is safe.