在役连续刚构桥顶升技术及应用

以某连续刚构桥顶升改造为背景,采用施工过程仿真分析方法,研究了顶升不同步性对上部结构承载力、支点反力的影响及顶升过程中原桥墩、临时墩荷载变化对承台、桩基内力的影响,并提出桥梁顶升施工方法、步骤和顶升过程的监测控制方法。研究结果表明:顶升施工过程中,下部结构最不利主拉应力仅为1.15 MPa,最大主压应力仅为4.72 MPa,临时墩最不利水平变位仅为1.57 mm,应力与变形均满足要求;但上部结构承载力不足,需采取体外预应力加固补强措施。应用结果表明,桥梁顶升施工技术工期短、造价低,不影响桥下通行,可以明显改善桥梁使用性能。

Elevation technology for raising continuous rigid frames of existing bridges

An existing rigid frames bridge was reformed with elevation method.The reforming process was studied with simulation analysis to study the effect of nonsynchronous rising on the bearing capability of the superstructure and the reaction force at the support,and the influence of the original piers and temporary piers on the internal force of the pile cap.The elevation method,procedure as well as its monitoring were presented.It was found that during the elevation period,the maximal principal tension stress is 1.15 MPa,the principal compression stress is 4.72 MPa,and the maximal horizontal displacement of the temporary pier is 1.57 mm.So the bearing capacity of the superstructure is insufficient,it needs to be strengthened by external tendon method.The application indicates that the elevation technology can obviously improves the performance of the bridge with the advantage of short construction,low cost and non-interfering of traffic.4 tabs,4 figs,8 refs.