高墩大跨连续刚构不对称浇筑施工受力特点及稳定性分析
发布时间：2018-11-08 14:30
【摘要】：高墩大跨连续刚构桥以其施工简便、受力合理、造价经济的优点，在国内得到了广泛的应用。对于修建在山区峡谷地区的连续刚构桥，由于受到地貌限制，主梁边中跨比不得不做的异于普通桥梁，这就使得采用悬臂浇筑施工的连续刚构桥在对称悬臂浇筑的基础上单悬臂浇筑剩余梁段。为了保证施工过程中的安全性，研究此类施工方法在桥梁施工阶段的结构受力特点与稳定性显得尤为重要。 四川甘孜洲大渡河特大桥是一座典型的采用不对称浇筑施工的连续刚构桥，在边跨合拢后中跨侧单悬臂浇筑多达5个号块，，本文以大渡河大桥施工过程作为分析对象，针对施工过程中的有关问题进行了研究与分析： ①利用平面分析软件Midas建立不对称悬臂浇筑、对称悬臂浇筑施工阶段有限元模型，分析两种施工方法在施工阶段的应力差异，并针对边跨支座反力随不对称悬臂浇筑施工阶段变化规律进行了相关研究。 ②利用零初始位置安装法与切线位置安装法在空间有限元软件ANSYS中实现悬臂浇筑施工阶段分析，并且验证了其可行性与精度。利用零位置安装法建立大渡河大桥施工阶段空间仿真模型，针对施工阶段剪力滞效应进行分析，得出剪力滞效应随施工阶段变化规律，并对该桥最大单悬臂、双悬臂施工阶段进行空间应力分析。 ③大渡河大桥不对称浇筑施工全过程弹性稳定分析：通过对不对称悬臂浇筑施工、对称悬臂浇筑施工，施工阶段稳定特征值对比分析，发现不对称悬臂浇筑施工在中跨侧单悬臂浇筑阶段稳定特征值跃阶提升的现象。 ④最大悬臂状态的稳定性研究：针对施工过程中的风荷载、挂篮跌落荷载、节段自重、施工荷载，考虑了四种可能的荷载工况。针对不对称浇筑施工最大单悬臂、双悬臂施工阶段进行弹性稳定性与考虑了几何非线性与材料非线性的非线性屈曲分析，得出在以上四种荷载工况作用下的稳定特征值与荷载加载系数，能够对该桥在最大单悬臂、双悬臂阶段的施工稳定性做出评价，可给实际工程提供参考。
[Abstract]:The continuous rigid frame bridge with high piers and long span has been widely used in China because of its advantages of simple construction, reasonable force and economical cost. For continuous rigid frame bridges built in mountain canyons, due to geomorphological constraints, the ratio of the middle to middle span of the main girder must be different from that of ordinary bridges. This makes the continuous rigid frame bridge constructed by cantilever pouring on the basis of symmetrical cantilever pouring the residual beam segment with a single cantilever. In order to ensure the safety of the construction process, it is particularly important to study the structural stress characteristics and stability of this kind of construction method in the bridge construction stage. The Ganzizhou Dadu River Bridge in Sichuan Province is a typical continuous rigid frame bridge constructed by asymmetric pouring. After the closure of the side span, there are up to 5 blocks of single cantilever in the middle span. The construction process of the Dadu River Bridge is taken as the analysis object in this paper. The related problems in the construction process are studied and analyzed: 1 the finite element model of asymmetric cantilever pouring and symmetrical cantilever pouring construction stage is established by using plane analysis software Midas. The stress difference between the two construction methods in the construction stage is analyzed, and the law of the reaction force of the side span bearing with the construction stage of asymmetric cantilever pouring is studied. (2) the method of zero initial position installation and tangent position installation is used to analyze the construction stage of cantilever pouring in ANSYS, and the feasibility and accuracy of the method are verified. The spatial simulation model of Dadu River Bridge in construction stage is established by using the zero-position installation method. The shear lag effect in construction stage is analyzed, and the variation law of shear lag effect with construction stage is obtained, and the maximum single cantilever of the bridge is obtained. The spatial stress analysis of double cantilever construction stage is carried out. (3) elastic stability analysis of Dadu River Bridge during the whole process of asymmetric pouring construction: through the construction of asymmetric cantilever pouring, the characteristic values of stability in construction stage are compared and analyzed. It is found that the steady eigenvalue of asymmetric cantilever construction in the stage of mid-span single cantilever placement is elevated by step. (4) study on the stability of the maximum cantilever state: considering the wind load, basket drop load, segment weight and construction load during construction, four possible load conditions are considered. According to the maximum single cantilever and double cantilever in asymmetric pouring construction, the elastic stability and nonlinear buckling analysis of geometric nonlinearity and material nonlinearity are carried out. The stability eigenvalues and load loading coefficients under the above four load conditions can be obtained to evaluate the construction stability of the bridge in the maximum single cantilever and double cantilever stages, which can be used as a reference for practical engineering.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.23
本文编号：2318755
[Abstract]:The continuous rigid frame bridge with high piers and long span has been widely used in China because of its advantages of simple construction, reasonable force and economical cost. For continuous rigid frame bridges built in mountain canyons, due to geomorphological constraints, the ratio of the middle to middle span of the main girder must be different from that of ordinary bridges. This makes the continuous rigid frame bridge constructed by cantilever pouring on the basis of symmetrical cantilever pouring the residual beam segment with a single cantilever. In order to ensure the safety of the construction process, it is particularly important to study the structural stress characteristics and stability of this kind of construction method in the bridge construction stage. The Ganzizhou Dadu River Bridge in Sichuan Province is a typical continuous rigid frame bridge constructed by asymmetric pouring. After the closure of the side span, there are up to 5 blocks of single cantilever in the middle span. The construction process of the Dadu River Bridge is taken as the analysis object in this paper. The related problems in the construction process are studied and analyzed: 1 the finite element model of asymmetric cantilever pouring and symmetrical cantilever pouring construction stage is established by using plane analysis software Midas. The stress difference between the two construction methods in the construction stage is analyzed, and the law of the reaction force of the side span bearing with the construction stage of asymmetric cantilever pouring is studied. (2) the method of zero initial position installation and tangent position installation is used to analyze the construction stage of cantilever pouring in ANSYS, and the feasibility and accuracy of the method are verified. The spatial simulation model of Dadu River Bridge in construction stage is established by using the zero-position installation method. The shear lag effect in construction stage is analyzed, and the variation law of shear lag effect with construction stage is obtained, and the maximum single cantilever of the bridge is obtained. The spatial stress analysis of double cantilever construction stage is carried out. (3) elastic stability analysis of Dadu River Bridge during the whole process of asymmetric pouring construction: through the construction of asymmetric cantilever pouring, the characteristic values of stability in construction stage are compared and analyzed. It is found that the steady eigenvalue of asymmetric cantilever construction in the stage of mid-span single cantilever placement is elevated by step. (4) study on the stability of the maximum cantilever state: considering the wind load, basket drop load, segment weight and construction load during construction, four possible load conditions are considered. According to the maximum single cantilever and double cantilever in asymmetric pouring construction, the elastic stability and nonlinear buckling analysis of geometric nonlinearity and material nonlinearity are carried out. The stability eigenvalues and load loading coefficients under the above four load conditions can be obtained to evaluate the construction stability of the bridge in the maximum single cantilever and double cantilever stages, which can be used as a reference for practical engineering.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.23
【参考文献】
相关期刊论文 前2条
1 王海蛟;;浅析世界连续刚构桥的发展历程[J];黑龙江交通科技;2006年05期
2 周军生,楼庄鸿;大跨径预应力混凝土连续刚构桥的现状和发展趋势[J];中国公路学报;2000年01期
本文编号：2318755
本文链接：https://www.wllwen.com/kejilunwen/jiaotonggongchenglunwen/2318755.html
