某墩梁固结预应力T梁固结墩区域梁体腹板八字裂缝成因分析  

Analysis on Causes of Eight-figure Crack in Girder Web Plate in Prestressed T-beam Consolidation Pier Zone of Pier and Beam Consolidation

作　　者：温建兴 武建中 WEN Jianxing;WU Jianzhong(Guangdong Heli Transportation Maintenance Technology Co.,Ltd,Guangzhou 510000,China;Guangdong Transportation Planning and Design Institute Group Co.,Ltd,Guangzhou 510000,China)

机构地区：[1]广东和立交通养护科技有限公司,广东广州510000 [2]广东省交通规划设计研究院集团股份有限公司,广东广州510000

出　　处：《城市道桥与防洪》2025年第3期236-240,共5页Urban Roads Bridges & Flood Control

摘　　要：预应力先简支后结构连续T形梁桥是30~50 m跨径桥梁经常采用的一种形式,但桥梁运营期发现T梁腹板普遍存在裂缝,主要表现形式为竖向裂缝和斜裂缝。针对某高速公路墩梁固结预应力T梁固结墩区域梁体腹板八字裂缝病害成因进行研究分析,该八字裂缝与剪切裂缝方向垂直,数量多且有一定发展,缝宽超限,会影响结构安全和耐久性。通过对裂缝分布的统计分析和数值模拟,确定了产生八字裂缝的根本原因为结构体系先天不足,墩顶未设置负弯矩束,墩梁固结区域的受力复杂,属于应力扰动区;主要原因是基础形式多样,在早期沉降速率不一,当不均匀沉降大于15 mm时墩梁固结区间会产生超限的拉应力;次要原因是联长过大,收缩徐变及温度产生了不利影响;此外,运营桥梁结构材料性能的劣化与损伤累积也导致了八字裂缝的持续发展。研究成果可为此类桥梁的设计与运营管养提供参考。Prestressed simply supported and then structurally continuous T-beam bridges are a commonly used form for spans of 30~50 m.However,during operation,it was found that cracks were commonly present in the web plates of T-beams,mainly in the form of vertical and diagonal cracks.This article mainly studies and analyzes the causes of the eight shaped crack disease in the web plate of the prestressed T-beam consolidation pier area of a certain highway pier.The eight shaped crack is perpendicular to the direction of the shear crack,with a large number and certain development.The crack width exceeds the limit,which affects the safety and durability of the structure.Through statistical analysis and numerical simulation of crack distribution,it has been determined that the root cause of the eight character crack is the inherent deficiency of the structural system,the absence of negative bending moment bundles at the pier top,and the complex stress in the consolidation area of the pier beam,which belongs to the stress disturbance zone.The main reason is that the foundation forms are diverse,and the settlement rate varies in the early stage.When the uneven settlement is greater than 15 mm,excessive tensile stress will occur in the consolidation zone of the pier and beam.The secondary reasons are excessive elongation,shrinkage,creep,and adverse effects on temperature.In addition,the deterioration and accumulation of damage in the performance of bridge structural materials have led to the continuous development of"eight character"cracks.The research results can provide a reference for the design,operation and maintenance of such bridges.

关 键 词：预应力T梁 墩梁固结 梁体腹板 八字斜裂缝 裂缝成因 

分 类 号：U445.7[建筑科学—桥梁与隧道工程]