Research on Bearing Capacity of Tall Piers During Incremental Launching Construction Considering Horizontal Thrust Effects
-
摘要: 在采用顶推施工的高墩桥梁中,高墩顶部在施工过程中会因摩擦力和上部结构重量的共同作用,造成墩顶发生位移,并在水平位移和上部结构重量作用下进一步影响桥墩承载力。此外,施工偏差等造成的墩身弯曲会进一步降低承载力。为研究水平推力与施工偏差对顶推施工中的高墩墩顶位移及承载力的影响,提出了一种考虑墩顶水平推力和墩身存在初始弯曲的高墩墩顶位移近似计算公式。同时,根据边缘屈服准则推导包含水平推力影响的极限承载力计算公式。以某多跨连续梁桥桥墩为研究对象,建立有限元模型验证公式的正确性,并开展敏感性分析。研究结果表明:公式计算结果与有限元模拟结果误差均在1%以内;由于工程中的高墩多为长柱,此时二阶弯矩的影响不可忽视,在顶推过程中桥墩受到水平推力和初始偏位的影响,偏心距增大系数增大,造成墩底弯矩增大,严重时会发生破坏风险;在实际工程中,水平推力和初始偏位对高墩极限承载力具有一定削弱作用。Abstract: In bridges with tall piers constructed using the incremental launching method, the pier top experiences displacement during construction due to the combined action of friction and superstructure weight. This horizontal displacement, coupled with the superstructure weight, further affects the bearing capacity of the pier. Furthermore, bending of the pier body caused by construction deviations further reduces the bearing capacity. To investigate the influence of horizontal thrust and construction deviations on both pier top displacement and bearing capacity during incremental launching, an approximate calculation formula for tall pier top displacement was proposed, considering both the horizontal thrust at the pier top and the presence of initial bending in the pier body. Simultaneously, a formula for calculating the ultimate bearing capacity incorporating the influence of horizontal thrust was derived based on the edge yield criterion. Taking the piers of a multi-span continuous girder bridge as the research object, a finite element model was established to verify the accuracy of the formulas, and a sensitivity analysis was conducted. The research results indicated that the errors between the formula calculation results and the finite element simulation results were within 1%. For tall piers (mostly long columns) commonly encountered in engineering, the influence of second-order bending moments could not be neglected. During incremental launching, piers subjected to horizontal thrust and initial eccentricity exhibited an increase in the eccentricity magnification factor, leading to larger bending moments at the pier base and posing a risk of failure under severe conditions. In practical engineering, horizontal thrust and initial eccentricity have a certain weakening effect on the ultimate bearing capacity of tall piers.
-
Key words:
- incremental launching /
- P-Δ effect /
- ultimate bearing capacity /
- geometric nonlinearity
-
[1] 李旭.曲线开口钢槽梁顶推施工阶段受力特性研究[D].西安:长安大学,2023. [2] 刘武,邓涛,袁梦雄,等.高墩小半径曲线钢箱梁桥顶推施工桥墩稳定性分析[J].建筑安全,2021,36(6):19-23. [3] 王志坚,卓卫东,刘迅,等.考虑高墩二阶效应的简化迭代计算方法[J].福州大学学报(自然科学版),2023,51(2):178-183. [4] 邓惠株.简支梁桥桥墩偏位对承载力影响及容许限值研究[D].重庆:重庆交通大学,2021. [5] 陆言,李鸿晶,杨筱朋,等.任意轴向荷载作用下高耸结构P-Δ效应高阶精确分析方法[J].固体力学学报,2025,46(1):79-92. [6] 左家强.复杂条件下顶推小半径连续弯梁设计研究[J].铁道工程学报,2019,36(6):56-61. [7] 胡平,杜钊,陈家龙,等.铁路连续刚构桥合龙顶推力分析[J].世界桥梁,2020,48(2):61-65. [8] 郭波.基于ISSA-GRU模型的顶推施工引起桥墩位移预测研究[J].施工技术(中英文),2025,54(10):95-99. [9] 盛兴旺,文颖,曾庆元.结构稳定理论[M].北京:中国铁道出版社有限公司,2021. [10] 龙驭球,包世华.结构力学[M].北京:高等教育出版社,2012. [11] 王超.塔式起重机位移及二阶效应研究[D].济南:山东建筑大学,2023. [12] 叶见曙,李国平.结构设计原理[M].北京:人民交通出版社股份有限公司,2021. [13] 交通运输部公路科学研究院.公路工程质量检验评定标准第一册土建工程:JTG F80/1-2017[S].北京:人民交通出版社,2018. -
点击查看大图
计量
- 文章访问数: 25
- HTML全文浏览量: 9
- PDF下载量: 0
- 被引次数: 0
登录
注册
E-alert
登录
注册
E-alert
下载: