丹江口水库特大桥地锚式桥台设计  

Design of Anchorage-Type Abutment of Danjiangkou Reservoir Bridge

作　　者：陶辰亮 刘朝辉 覃作伟 丁望星 TAO Chenliang;LIU Zhaohui;QIN Zuowei;DING Wangxing(Hubei Provincial Communications Planning and Design Institute Co.,Ltd.,Wuhan 430051,China;Hubei Communications Investment Group Co.,Ltd.,Wuhan 430050,China)

机构地区：[1]湖北省交通规划设计院股份有限公司,湖北武汉430051 [2]湖北交通投资集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2024年第5期16-21,共6页Bridge Construction

基　　金：湖北省交通运输厅科技项目(2020-2-2-1)。

摘　　要：丹江口水库特大桥为主跨760 m的双塔双索面部分地锚式混合梁斜拉桥,1号、4号桥台采用地锚式设计。基于桥台规模限制及结构耐久性考虑,地锚式桥台创新采用了空腔式箱形台身结构(由底板、墙身、盖板和锚台段主梁等组成)。桥台全长45.8 m、顶宽31.6 m,共设置18个空腔,采用矩形扩大基础。为实现传力平顺,地锚式桥台台梁过渡段台身采用肋墙式构造;为降低桥台整体应力水平、提升桥台的抗裂性能,在台身侧墙设置竖向预应力;为增强1号桥台的抗滑稳定性,在台身侧墙设置CFRP岩土锚杆,锚杆锚入中风化基岩。采用有限元法对地锚式桥台构造的受力性能及抗滑稳定性进行验证,结果表明:桥台总体应力分布均匀,台梁过渡段应力过渡平顺,桥台纵、横隔墙应力以压应力为主,并且关键部位有一定的压应力储备;1号桥台设置CFRP岩土锚杆后其抗滑稳定系数提升了20%以上。The Danjiangkou Reservoir Bridge is a two-pylon,hybrid girder cable-stayed bridge with a main span of 760 m and double planes of stay cables.The abutments No.1 and No.4 are anchorage-type structures to accommodate the pairs of earth-anchored stay cables.The anchorage-type abutments are hollow box structures that are composed of bottom slabs,walls,cap slabs as well as the main girder in the anchor section and the abutment foundation.Measuring 45.8 m in total length and 31.6 m in top width,the rectangular-spread-foundation-supported abutment comprises 18 cells.To achieve smooth force transfer,the transition between the abutment and main girder is designed as a ribbed wall structure.To reduce the integral stress level and improve the anti-cracking performance of the abutment,the walls of the abutment are fitted with vertical prestressing tendons.To enhance the anti-sliding stability of the abutment No.1,the walls are equipped with CFRP anchor rods that are socketed in the moderately-decomposed bedrock.The mechanical property and anti-sliding stability of the anchorage-type abutment were verified by numerical simulation.It is demonstrated that the overall stress distribution in the abutment is even,and stress transition in the joint section of the abutment and main girder is smooth.The longitudinal and transverse walls of the abutment are mainly in compression,with a degree of compressive stress margin in the key locations.After equipped with CFRP anchor rods,the anti-sliding stability coefficient of the abutment No.1 is improved by 20%.

关 键 词：部分地锚式斜拉桥 地锚式桥台 空腔式箱形台身 肋墙式台身 竖向预应力 岩土锚杆 结构设计 有限元法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.21[交通运输工程—道路与铁道工程]