钢绞线切断回缩对拆除预应力梁桥的影响研究  

Research on Influence of Steel Strand Cutting Retraction on Demolition of Prestressed Beam

作　　者：王慧慧 Wang Huihui(Guangzhou Municipal Engineering Design&Research Institute Co.,Ltd.,Guangzhou 510095,China)

机构地区：[1]广州市市政工程设计研究总院有限公司,广东广州510095

出　　处：《市政技术》2023年第9期235-241,248,共8页Journal of Municipal Technology

摘　　要：采用SPMT(Self-Propelled Module Transporters)拆除某预应力梁桥过程中,钢绞线切断后产生了回缩现象。因此,为保证施工安全顺利进行,采用Midas FEA软件建立全桥实体模型,研究了钢绞线切断后回缩对该梁桥拆除过程的影响;确定了切割后钢绞线“先张+后张”的理论预应力分布;在模型中输入锯齿状钢束简单模拟了理论预应力分布。计算结果表明,切割后在简支状态下结构变形和应变随钢绞线回缩量的增大而增大;对预估梁桥预应力损失和实际预应力损失进行了对比,其结果印证了梁桥拆除施工方案的安全性。During the process of dismantling a prestressed concrete beam bridge with self-propelled module transporters(SPMT),the retraction phenomenon happened after the steel strand was cut.In order to ensure the safe and smooth construction,a solid unit was established by Midas FEA software to study the influence of steel strand retracting after cutting on the dismantling process of the girder bridge;The theoretical prestress distribution of“pre tensioning+post tensioning”has been determined,which was simply simulated by inputting serrated steel beams into the model.The calculation results show that the deformation and strain of the structure increase with the increase of the shrinkage of the steel strand in the simply supported state after cutting;The estimated prestress loss of the girder bridge is compared with the actual prestress loss,and the results confirm the safety of the demolition construction scheme of the girder bridge.

关 键 词：预应力 连续梁 钢绞线回缩 SPMT 快速拆除 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]