【作者】 赵晨；

【导师】 张东明；

【作者基本信息】 重庆大学 ， 安全技术及工程， 2011， 硕士

【摘要】 随着交通事业的不断发展,科学技术的不断提高,经常需要在大江、大河、深沟修建更多更大跨径、更为经济合理的大跨径连续刚构桥梁。大桥的建成要经历一个较长而复杂的施工过程,为确保桥梁结构合龙精度、成桥线形和运营一定时间后能达到设计所要求的标高,施工时预测上部结构在每一施工阶段的挠度,并根据实时监测值来分析、指导施工过程中每个阶段的行为,就非常重要。施工过程中,随着悬浇梁段的增加,结构体系不断变化,每一梁段的增加都对现有结构的线形及内力产生一定的影响,种种影响因素将导致施工过程中桥梁线形、内力与理想目标存在一定的偏差,这种偏差积累到一定程度如不及时加以识别和调整,最后使得桥梁线形扭曲、结构失稳,合拢困难,甚至对桥梁结构安全埋下隐患。本文介绍了国内外桥梁工程施工监控发展,对连续刚构桥梁的施工监控的目的,原则和方法进行了基本阐述,最终涪江一桥采用正装分析法进行计算,并分析了桥梁结构状态中的误差影响。文章以合川区涪江一桥工程项目为背景,采用空间有限元方法建立结构分析模型,利用大型有限元软件Midas/Civil对桥梁进行理论计算。根据参数的敏感性分析确定了结构设计参数中的主要设计参数,并根据实际情况调整计算参数、修正理想状态、进行反馈控制分析、预测施工立模标高,以更好的指导施工。针对涪江一桥监控的实施,介绍了测试中所采用的仪器及其原理,详细的分析了应力测试中存在的误差,通过对测试结果中混凝土收缩、徐变应变及温度应变误差的消除,最终得到较为真实的应力值。在线形监测中,利用灰色原理对立模标高进行修正,取得了较好的效果,通过对温度的监测,分析了温度对线形的影响。通过对桥梁施工过程的模拟计算分析,根据涪江一桥监控实测数据与理论计算结果进行对比,分析应力和线形变化情况,严格控制各个控制截面的挠度和应力的发展,最终顺利完成桥梁监控工作。更多还原

【Abstract】 With the continuous development of transport and the improvement of science and technology, it is need to build more greater span and reasonable bridge in the rivers and deep groove. The completion of the bridge was known to be a long-term and multi-step process. To ensure the accuracy of closure, the bridge line and design requirements after normal operation, it seemed especially important to predict the deflection of the upper structure of each construction stage and guide construction by the real-time measured value.With the increase of the girder segment cast with cantilever method and the constantly changing of the structure system, the increment of the girder segment could have effect on the line shape of bridge and the stress of structure. The influencing factors may lead to the difference of the practical value of line shape and stress and the design value. The line shape would be too twisted to shut and the structure would be unsafe if the difference wasn’t controlled timely and even brought some hidden troubles in the structure.This paper introduces the development of construction monitoring at home and abroad. Detailed summary and analyze the theories of monitoring, the objective and the methods of construction monitoring and the error influence of the structure state. At last the Fu River Bridge adoptted orderly-erecting analysis method for calculation. The Fu River Bridge in hechuan district is a continuous rigid frame bridge. Based on the finite element theory,it was relatively right to adopt software Midas/Civil for calculation. The main design parameters were determined by the consequence of sensitivity analysis. According to the actual state, the correction of structure parameters and the model, the feedback of analysis results and the prediction of formwork erection elevation were completed for guiding construction better.Aiming at implementation of monitoring, this paper presented the principle of test instruments and detailed analysis about stress test errors. Through the elimination of the strain of concrete shrinkage and creep and the strain caused by temperature, the more realistic stress value was acquired.. Based on the grey theory, the formwork erection elevation was modified. And through the temperature monitoring, the effect of temperature on line shape was analyzed.Through the calculation of construction process, the monitoring results were analyzed compare to the theoretical results. The change of stress and line shape were mastered. At last the monitoring of the bridge was completed successfully.更多还原