某特大简支梁桥墩身开裂的事故排查

发布时间：2018-04-25 09:21

本文选题：桥墩开裂 + 临时连接螺栓　；参考：《土木建筑与环境工程》2015年S2期

【摘要】：桥梁裂缝严重影响结构安全性和耐久性,不符合"绿色建造"和"可持续发展"的相关理念。文章对某特大简支梁桥桥墩开裂现象进行事故排查,为裂缝修复工作提供依据,以促进桥梁施工各个环节的规范化。考虑支座中未拆除的临时连接螺栓对墩、梁的约束作用,首先以Abaqus分析未拆除的临时连接螺栓对支座水平剪切变形的约束作用,然后以Midas计算了3种最不利工况下桥墩墩顶处的支座反力,最后以ANSYS分析3种最不利荷载组合时墩身应力。结果表明,即使按墩顶的4个纵向活动支座临时连接被同时破坏的最不利情况考虑,墩身在3种最不利工况下的最大主拉应力也仅为0.08MPa,远未达到C30混凝土的拉应力容许值0.73MPa。因此,架梁完成后未及时拆除支座临时连接的限位螺栓并不是导致该桥墩身开裂的主要原因,事故调查需从其他方面入手。但该疏忽会在桥墩中引起拉应力,应尽量避免,确保桥梁建造的各个环节更为规范。
[Abstract]:Bridge cracks seriously affect the safety and durability of structures, and do not conform to the related concepts of "green construction" and "sustainable development". This paper investigates the cracking phenomenon of pier of a super simple beam bridge in order to provide the basis for repairing cracks and to promote the standardization of each link of bridge construction. Considering the constraint effect of unremoved temporary connection bolt on pier and beam, Abaqus is used to analyze the constraint effect of unremoved temporary connection bolt on horizontal shear deformation of support. Then Midas is used to calculate the support reaction forces at the top of the piers under three most unfavorable conditions. Finally, the stress of the piers under the three most unfavorable loads is analyzed by ANSYS. The results show that the maximum main tensile stress of piers under three most unfavorable conditions is only 0.08MPa even if the temporary connection of four longitudinal movable supports at the top of the pier is damaged simultaneously, which is far from the allowable value of tensile stress of C30 concrete (0.73 MPA). Therefore, the failure to remove the limit bolt of temporary support connection after the completion of the erection beam is not the main cause of the cracking of the pier body, and the accident investigation should be started from other aspects. However, the neglect will cause tensile stress in the pier and should be avoided as far as possible to ensure that each link of the bridge construction is more standardized.
【作者单位】：重庆大学土木工程学院;重庆大学山地城镇建设安全与防灾协同创新中心;
【基金】：国家自然科学基金(51578098) 重庆科委项目(20130844)
【分类号】：U447

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