高铁矮塔斜拉桥索梁锚固结构的传力机理研究OA
Research on Force Transmission Mechanism of Cable-Girder Anchorage Structure of a Low-Tower Cable-Stayed Bridge for a High-Speed Railway
[目的]本文主要研究高铁矮塔斜拉桥索力最大处主梁节段锚固区的应力状态及索力传递机理,分析锚块与主梁腹板、翼缘板接触面的荷载分配比例,以及箱内横隔梁、锚下钢筋对传力的影响规律.[方法]以某高铁矮塔斜拉桥为依托,采用 MIDAS/FEA 软件建立索力最大处主梁节段及锚固区有限元模型,分析锚固区各部件应力状态及索力传递机理;引入"荷载传递比"指标,研究锚块与主梁腹板、翼缘板两个接触面的荷载分配比例;同时,研究箱内横隔梁、锚下钢筋对传力的影响规律.[结果]锚垫板、预埋管存在小部分应力集中区域,最大等效应力分别达68.6 MPa 和94.6 MPa;由于附加弯矩的作用,混凝土锚块在短斜边处存在较为危险的应力集中区域;索力经由锚垫板传递给锚块,锚块通过与主梁腹板、翼缘板的接触面将索力较为平顺地传递至主梁;随着斜拉索倾角变大,锚块与腹板接触面所传递顺桥向荷载比例由 35.7％逐渐增大至 44.3％,传递竖桥向荷载比例由 58.9％逐渐增大至63.5％;箱内横隔梁的配置可使腹板与锚块接触尖端处的拉应力减小 2～4 MPa,缓解应力集中现象;锚下钢筋的配置使锚块与腹板接触面上的应力不均匀系数降低 10％左右,整个截面的应力分布更为均匀,锚下钢筋直径与间距在常规范围内对结构应力状态无明显影响.[结论]矮塔斜拉桥锚固区设计中需关注锚垫板、预埋管及混凝土锚块短斜边的应力集中问题;通过设置箱内横隔梁可有效缓解腹板与锚块接触尖端的拉应力,加强锚下钢筋可改善应力分布均匀性,保证结构安全;斜拉索倾角增大会提高锚块与腹板接触面传递的荷载比例.
[Objective]To investigate the stress state and cable force transmission mechanism in the anchorage zone of the main girder segment under maximum cable force in a high-speed railway cable-stayed bridge,and to analyze the load distribution on anchor-block-web and anchor-block-flange interfaces,as well as the effects of inner transverse diaphragms and under-anchor reinforcement.[Methods]Using MIDAS/FEA,a finite element model of the main girder segment under maximum cable force and its anchorage zone was established based on a high-speed railway cable-stayed bridge.The"load transfer ratio"index was introduced to quantify load distribution on the two contact interfaces.The influences of inner transverse diaphragms and under-anchor reinforcement on force transfer were also studied.[Results]Minor stress concentrations occurred in the anchor plate(68.6 MPa)and embedded duct(94.6 MPa).Due to additional bending moment,a relatively critical stress concentration appeared at the short inclined side of the concrete anchor block.The cable force was smoothly transferred from the anchor plate to the anchor block,and then to the main girder via the web and flange interfaces.As cable inclination increased,the longitudinal load ratio on the anchor-block-web interface rose from 35.7％to 44.3％,and the vertical ratio from 58.9％to 63.5％.Inner transverse diaphragms reduced the tensile stress at the web-anchor block tip by 2～4 MPa.Under-anchor reinforcement reduced the stress non-uniformity coefficient by about 10％,improving stress distribution,while its diameter and spacing(within conventional ranges)had no significant effect on the structural stress state.[Conclusion]Design of the anchorage zone should address stress concentrations at the anchor plate,embedded duct,and short inclined side of the anchor block.Inner transverse diaphragms can effectively relieve local tension,and proper under-anchor reinforcement can enhance stress uniformity and structural safety.Larger cable inclination increases the load transferred through the anchor-block-web interface.
朱泽众;曹振杰;傅青松;张迅
西南交通大学桥梁工程系,成都 610031中铁十五局集团有限公司,上海 200070中铁十五局集团有限公司,上海 200070西南交通大学桥梁工程系,成都 610031||西南交通大学桥梁智能与绿色建造全国重点实验室,成都 611756
交通工程
铁路桥梁混凝土锚固结构应力状态荷载传递锚下钢筋
railway bridgeconcrete anchorage structurestress stateload transferunder-anchor rein-forcement
《铁道标准设计》 2026 (8)
64-72,9
国家自然科学基金项目(52478470)
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