【作者】 何先民；

【导师】 韦成龙； 刘小燕；

【作者基本信息】 长沙理工大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 预应力混凝土连续刚构桥是目前山区桥梁中应用最为广泛的桥型,上部结构的施工主要采用对称悬臂浇注施工方法。对于高墩大跨径连续刚构桥而言,由于在施工过程中受多种因素的影响,施工阶段结构的变形、截面的应力状态不仅关系到施工质量和施工安全,还直接影响到成桥线形与成桥的受力状态,因此,对大桥进行施工控制显得尤为重要。在对现有的国内外预应力混凝土连续刚构桥的特点和施工控制的理论及研究现状进行总结和分析的基础上,本文针对野三河特大桥挂篮悬臂施工的特点,结合大桥施工方案,采用前进分析法,利用有限元程序对施工过程进行了仿真计算,得到控制过程各个控制截面的内力和控制点的预抬值,制定施工控制的应力和线形控制文件;根据自适应控制法对野三河特大桥进行施工控制,将仿真计算结果和实测数据进行监测、分析、调整,使大桥施工在有序的控制之中。为该桥的顺利合拢和成桥后的线形、内力满足设计要求提供保障。野三河特大桥在施工过程中,受到了下游水电站施工爆破的影响,剧烈的爆破振动,梁体出现开裂现象,为了探讨开裂的原因,保证大桥质量,需要了解爆破对大桥的影响,为此,本文采用时程分析法对爆破影响进行计算分析。根据现场采集的振动参数,拟合不同炸药使用量下桥梁基础振动的典型加速度时程曲线,分施工期和成桥后两个阶段,建立有限元分析模型,对该桥在不同工况一致激励下的结构时程反应作了对比分析研究,为大桥施工安全、质量及水电站施工爆破炸药量的控制提供判断依据,也为同类桥梁施工控制提供一定的参考价值。更多还原

【Abstract】 Prestressed concrete continuous rigid frame bridge, which mainly used symmetrical cantilever construction method, is a quite common bridge style in the mountains area. as the long-span continuous rigid frame bridge structure is concerned,the deformation, the cross-section of the stress and strain state in the construction phase have a direct impact on the bridge’s line shape and the finish period of force state. therefore, the construction control on bridge is particularly important.Based on the analysis of the status quo in the current domestic and foreign continuous prestressed concrete rigid frame bridge construction and the summary of the control theory, in allusion to the characteristics of cantilever bridge construction in Yesanhe bridge,combined the bridge construction plan, this paper uses the Finite element program to simulate the real construction, then, gain each control section’s internal force and pre-drive up value to establish control stress and line shape documents and institute detailed rules according to characteristics of Yesanhe bridge, analyze simulation results compared with the measured data to guarantee the line shape of the last stage and the internal force to meet the design requirements.During the construction process of Yesanhe bridge, due to the impact of intense burst in the construction of hydropower station, lying in downstream, this bridge has generated many cracks on the beam. We need to know the burst impact on the quality and safety of the bridgein the construction control, therefore, according to the acquisition of vibration parameters in the blasting locale, we establish typical acceleration-history curve in this paper,which reflect the bridge foundation’s vibration under the different volum of explosives,then,divided the construction period and the finish period into two phases, set up a finite element analysis model and use comparative analysis method to analyze the history responses of the bridge in different work conditions. This paper provided the basis for the safety, quality in the bridge construction and the rendrock volume of blasting in hydropower station construction, also provide some reference value for the control of similar bridge construction.更多还原