时变效应对缓粘结预应力连续梁线形的影响  

Influence of Time-Dependent Effect on Alignment of Retard-Bonded Prestressed Continuous Beam

作　　者：崔跃 CUI Yue(China Railway Construction Group Co.Ltd.,Beijing 100040,China)

机构地区：[1]中铁建设集团有限公司,北京100040

出　　处：《铁道建筑技术》2024年第11期74-77,156,共5页Railway Construction Technology

基　　金：中铁建设集团有限公司基金资助项目(21-36c)。

摘　　要：为揭示时变效应对缓粘结预应力连续梁线形的影响规律,采用数值模拟,系统分析了收缩徐变、昼夜及季节温差、温度梯度等时变效应对缓粘结预应力桥主梁线形的影响。研究结果显示:成桥后的1~5年内,梁体由于收缩徐变产生的竖向变形增长速度最快,这一阶段的变形量可达到成桥后总变形量的75%;适当提高混凝土强度等级,可有效减小由收缩徐变引起的梁体下挠;在季节升温及降温作用下,最大纵向位移均出现在靠近固定支座的梁端,升温时为8.16 mm,降温时为5.53 mm,最大横向位移均出现在远离固定支座的梁端,升温时为13.9 mm,降温时为9.53 mm;由日照温差引起的梁体线形变化相对较小,其变化值小于2 mm,这表明日照温差对缓粘结预应力连续梁线形的影响不如其他时变效应显著。This study investigates the time-dependent effects on the spatial configuration of retard-bonded prestressed continuous beams through comprehensive numerical simulation.The research analyzes the influence of shrinkage,creep,diurnal and seasonal temperature variation,as well as temperature gradients.Key findings include shrinkage and creep cause significant vertical deformation,with 75%of the deformation occurring within the first five years after the completion of the bridge.To mitigate downward deflection,it is recommended to increase the concrete grade.Seasonal temperature fluctuations induce maximum longitudinal displacement at the fixed support end,with 8.16 mm during temperature rise and 5.53 mm during temperature drop.Seasonal temperature variations result in maximum lateral displacement at the end furthest from the fixed support,with 13.9 mm during temperature rise,and 9.53 mm during temperature drop.Diurnal temperature differences have a relatively minor impact on the beam′s spatial configuration,with variations below 2 mm.These findings demonstrate that the spatial configuration of retard-bonded prestressed continuous beams is primarily influenced by shrinkage,creep,and seasonal temperature fluctuations,while diurnal temperature variations have a lesser effect.

关 键 词：时变效应 缓粘结预应力 连续梁桥 桥梁线形 

分 类 号：U448.215[建筑科学—桥梁与隧道工程]