大跨度箱涵下穿铁路的顶力智能控制研究

Research on Intelligence Control for Jacking Forces of Long-span Box Culvert Underpassing Railway

大跨度箱涵下穿既有铁路时顶力较难控制,易发生箱涵姿态的较大偏移从而影响施工质量.本文以大跨度箱涵下穿既有铁路工程为研究对象,通过对箱涵底板内力的实时监测,并根据由有限元软件建立的大跨度五孔箱涵模型模拟其顶进过程,探究其在顶力与进尺不同情况下箱涵轴线偏移情况,为顶力的实时调整提供依据.基于上述研究在工程中实现了对顶力的智能控制,并通过分析箱涵中轴线偏差实测数据对工程质量进行了评估.研究结果表明,通过底板内力监测数据实时调整总顶力可使其每镐顶力与摩阻力基本相当,未造成顶力浪费;箱涵顶进过程中总顶力、左右顶力比值与总进尺均与轴线偏移存在一定关系,为顶力智能控制提供了参考;在大跨度箱涵顶进过程中对顶力的智能控制能较好地控制箱涵的姿态,将轴线偏差控制在50mm以内,实现工程的高效性与精准性.

When the long-span box culvert is underpassing the existing railway,it is difficult to control the jacking force,and the axis is likely to lie greatly offset,affecting the construction quality.The paper made research for the long-span box culvert underpassing the existing railway to realize the real-time monitoring of the internal force of box culvert floor,and a kind of finite element software was used to establish a long-span five-hole box culvert model to simulate its jacking process which was able to make research for the displacement of box culvert axis under different conditions of top force and footage,and according to this information,the intelligence control of jacking force had been realized.The measured data of the central axis deviation of the box culvert was analyzed to evaluate the project quantity.Research indicated that according to the internal force monitoring data of the box culvert floor,the total jacking force was able to be adjusted in real time to make the jacking force be basically equal to resistance during the jac king process which could be thought of the jacking force had not been too large to cause jacking force wasted.There were some functional relationships among the total jacking force,the ratio of left jacking force and right jacking force,total footage and box culvert axis deviation,which could provide a reference.The attitude of the box culvert was controlled more effectively by the intelligence control of jacking force and the axis deviation was controlled within 50mm to achieve high efficiency and precision of the project during the process of jacking the long-span box culvert.