桥梁顶推施工对既有线高铁桥墩变位影响及沉降预测分析

Analysis of the Influence of Bridge Jacking Construction on the Displacement of the Existing High-speed Railway Pier and the Settlement Prediction

随着桥梁顶推施工在新建线路跨越既有线施工中的广泛应用,关于桥梁顶推施工对既有高铁桥墩变位影响的研究亟待深入。为研究桥梁顶推全过程施工对邻近既有高铁桥墩变位的影响,以郑济铁路ZJTLSG-1标跨京沪高铁特大桥工程为依托,基于监测数据,分析顶推施工关键施工工况对邻近既有高铁桥墩变位及沉降的影响;然后,采用先进的BP神经网络技术对相邻高铁线路工后沉降进行预测。结果表明:(1)既有高铁桥墩在顶推全过程施工完成后发生沉降且既有高铁桥墩水平移动方向与顶推方向相反;(2)既有桥墩的水平位移及竖向位移均从近施工侧到远离施工侧呈递减规律;(3)采用BP神经网络对既有桥墩进行沉降预测,预测值与实测值基本吻合,预测可靠。

With the wide application of bridge jacking construction in the construction of new lines crossing existing lines,the research on the influence of bridge jacking construction on the pier displacement of existing high-speed railway is in urgent need of development.In order to study the influence of the whole process of bridge jacking construction on adjacent existing high-speed railway pier displacement,based on the ZJTLSG-1standard cross Beijing to Shanghai high-speed railway bridge project of Zhengji Railway,the influence of key construction conditions of jacking construction on adjacent existing high-speed railway pier displacement and settlement was studied based on monitoring data.Then,the advanced BP neural network technology is used to predict the settlement of adjacent high-speed railway.The results show that:(1)the existing high-speed rail pier settlement occurs after the construction of the whole process of jacking and the horizontal movement direction of the existing high-speed rail pier is opposite to the jacking direction;(2)The horizontal and vertical displacements of the existing piers decrease from the near to the far side of construction;(3)BP neural network is used to predict the settlement of the existing pier.The predicted value is basically consistent with the measured value,and the prediction is more accurate.