斜拉桥塔索锚固区空间应力分析

结合恩施市施州大桥的设计,运用大型通用分析软件ANSYS,采用空间有限元的方法,分2种工况,对其空心预应力混凝土桥塔塔索锚固区进行了空间应力分析,并且比较了传统U形布束方式和井字方式的优缺点。分析结果表明:通过合理布置预应力粗钢筋,可以抵抗斜拉索水平力产生的不利影响,满足结构的使用要求;斜索锚固区段采用箱形截面的桥塔,索力的水平分量在没有斜索锚固的箱体部分内引起较大的顺桥向拉应力,在斜索直接锚固的箱体部分,引起靠外壁部分、横桥向较大的拉应力;顺桥向预应力筋应布置在没有斜索锚固的箱体内,横桥向预应力筋则重点布置在斜索直接锚固的箱体靠外侧部分;塔索锚固区的受力以正应力为主,只要控制塔索锚固区正应力分布,塔索锚固区的受力就可得到有效控制。

Spatial Stress Analysis of the Cable Anchorage Zone of Cable-stayed Bridge

According to the design of Shizhou bridge in Enshi city,the analysis of the spatial stress distribution of the cable anchorage zone is carried out in two cases by making use of the common analysis software-ANSYS.The advantages and disadvantages of traditional U type and # type layout of prestressed tendons are analyzed.The results indicate that,the affection caused by the horizontal components of the cable can be resisted by reasonable layout of the prestressed tendons and the requirement of usage can be reached,the horizontal components of cable forces cause a rather large longitudinal tense stress at the non-anchorage zones and great transverse tense stress at outside zones of anchorage.So the prestressed tendons should be put in the right places according to the analysis.The normal stress is the main part in the anchorage zone,when the normal stress be controlled,the force in the anchorage zone be controlled also.