大跨度曲线钢箱梁上跨双线铁路施工全过程性能监测研究

Research on Whole Process Performance Monitoring of Large-span Curved Steel Box Girder Overcrossing Double-track Railway Construction

针对曲线钢箱梁上跨双线铁路施工安全风险高的问题,文章以宁马高速公路改扩建涉铁工程为依托,基于Midas Civil建立了钢箱梁推拉施工有限元模型,对施工过程桥梁结构进行了仿真计算分析,并实时监测了拖拉过程中钢箱梁的线形及导梁应力变化,研究了拖拉过程导梁的应力变化趋势和钢箱梁的变形规律。研究结果表明,监测数据和数值模拟数据的变化趋势一致,两种方法对比分析可有效反映结构受力状态。钢箱梁在拖拉施工过程中的不利状态为导梁上墩之前的最大悬臂状态和上墩阶段,保证导梁上墩前的合理施工状态是顺利完成钢箱梁拖拉施工的关键。

Aiming at the problem of high safety risk in the construction of curved steel box girder overcrossing double-track railway,based on Nanjing-Ma'anshan Expressway reconstruction and expansion railway related engineering,the finite element model of steel box girder dragging construction is established based on Midas Civil.The bridge structure during the construction process is simulated and analyzed,and the alignment and guide beam stress changes of the steel box girder during the dragging process are monitored in real time.The stress change trend of the guide beam and the deformation law of the steel box girder during the dragging process are studied.The results show that the change trend of monitoring data and numerical simulation data is consistent,and the comparative analysis of the two methods can effectively reflect the stress state of the structure.The unfavorable state of the steel box girder during the dragging construction process is the maximum cantilever state before the guide beam reaching the pier and the reaching pier stage.Ensuring the reasonable construction state before the guide beam reaching pier is the key to successfully completing the dragging construction of the steel box girder.