自锚式悬索桥混凝土主缆锚固区受力特性研究

Study on the stress characteristics of the anchorage zone of the concrete main cable of a self-anchored suspension bridge

摘要:

为研究双边箱主梁自锚式悬索桥主缆锚固区的传力机制及应力分布,以某实际双边箱主梁自锚式悬索桥为例,采用Midas建立杆系全桥模型验证ANSYS实体模型的准确性,结合ANSYS有限元软件的最不利工况(主缆力最大时)锚固区实体模型,研究了双边箱锚固区在三向预应力、主缆力等作用下端横梁、次横梁、散索区等主要部位的应力云图,得到了双边箱混凝土主缆锚固区的传力路径和应力分布规律。结果表明：实体局部模型与整体模型仅有3.8%的竖向力误差,间接验证了实体局部模型的准确性；主缆力快速的通过后锚板扩散至端横梁,顺桥向压应力从后锚面最大值-7.07MPa,在端横梁范围内迅速扩散下降至-1.6MPa,再由端横梁传递给纵向箱室；锚固段散索区混凝土主应力-1.1MPa,在三向预应力作用下,受力状态良好；双边箱结构传力路径明确,顺桥向传递路径为：主缆→主缆锚板→散索区混凝土→端横梁→锚固段主梁。

Abstract:

SIn order to study the force transmission mechanism and stress distribution of the main cable anchorage zone of a bilateral box girder self anchored suspension bridge, taking an actual bilateral box girder self anchored suspension bridge as an example, Midas was used to establish a full bridge model of the rod system to verify the accuracy of the ANSYS solid model. Combined with the most unfavorable working condition (when the main cable force is maximum) of the ANSYS finite element software, the stress cloud maps of the main parts such as the lower crossbeam, secondary crossbeam, and scattered cable zone of the bilateral box girder anchorage zone under the action of three-dimensional prestress, main cable force, etc. were studied, and the force transmission path and stress distribution law of the bilateral box concrete main cable anchorage zone were obtained. The results indicate that there is only a 3.8% vertical force error between the local model and the overall model, indirectly verifying the accuracy of