【作者】 陈湛荣；

【导师】 周水兴；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 斜拉桥施工过程仿真计算是实施施工控制的基础,本文以湖北省恩施洲施州大桥为工程背景,应用结构仿真技术和施工控制理论,对PC斜拉桥施工仿真与控制进行了研究。首先,本文应用控制论的方法对目前的PC斜拉桥施工控制方法进行分类研究,寻求合理的控制思路;通过对斜拉桥施工过程仿真计算理论的分析研究,提出了一种适用于中小跨径混凝土斜拉桥索力计算的“二阶段法”。该方法省去了中间的倒装过程,计算速度快,用时少,利用该方法可以两步到位求出合理成桥与施工索力,能够考虑混凝土的收缩徐变以及合龙段不闭合力的影响,也能考虑非线性的影响。用“二阶段法”计算得出的成桥索力与施工索力闭合良好,误差不超过5%,且与经典方法计算得出的索力几乎一致,且满足施工阶段及运营阶段的要求,应力分布均匀。然后以五座斜拉桥有限元模型作为研究对象,得出考虑几何非线性效应与不考虑非线性效应的结构索力、弯矩及位移的响应情况。并对数据进行比较分析,得出是否考虑斜拉桥几何非线性效应的临界点,提出了几何非线性影响系数的经验表达式。采用桁架单元线性分析的结果乘以几何非线性系数即可得出非线性近似解答。在这基础上,建立有限元模型对施州大桥进行施工过程仿真计算,确定了施州大桥合理的成桥状态与施工状态。最后,结合仿真计算结果,具体阐述了施州大桥施工控制系统,在各施工阶段中,进行了状态变量(控制点位移、索力、控制截面应力及塔顶偏位)的实测值与相应理论值的差别分析研究,用以验证所作施工控制系统的有效性。本文的相关成果对PC斜拉桥的施工仿真计算与控制具有一定的参考价值。并为合理索力计算及非线性效应的计算提供了一种新的简化方法。更多还原

【Abstract】 The simulation analysis for constructing of Cable-Stayed Bridge is the foundation of the construction control. Based on the Shizhou Cable-Stayed Bridge in Enshi City,Hubei Province, according to structural simulation analysis technology and construction controlling theory, the simulation analysis and construction control of prestressed concrete Cable-Stayed Bridge is studied in detail.First, the methods which construction control of prestressed concrete Cable-Stayed Bridge currently used are studied separately by using controlling theory,and then a rational thinking of control for the bridge is sought. Through the analysis and research of the simulation analysising theory to the constructing of Cable-Stay Bridge, proposed the“Two-Stage Method”which used for the cable tension optimization on short or medium span prestressed concrete Cable-Stayed Bridges. This method can get the reasonable cable tensions in two steps without the back running analysis. It calculates faster than the classical methods. It can consider the concrete shrinkage and creep and the non-closure force of the closure section, and it can consider nonlinear influence too. The result of "Two-Stage Method" whose error inside 5% is trusty, and it is nearly identical with classical method. It can meet construction stage and using stage, and the stress is distributed evenly.Then regard finite element model of five cable-stay bridges as the research object, obtain the response of cable tension, moment and displacement, which consider the geometrical nonlinearity and don’t consider geometrical nonlinearity. And compare and analysis to the data, obtain the critical point of what consider geometrical nonlinearity or not of Cable-Stay Bridge. Propose the experience formula of the influence coefficient of geometrical nonlinearity influence coefficient. Then geometrical nonlinearity approximately answer can be obtained which adopt the result of linear analysis of the truss to multiply by the influence coefficient of geometrical nonlinearity influence coefficient. On the basis of this, set up finite element model and carry on the structural simulation analysis to confirm the reasonable construction stage and using stage of the Shizhou Cable-Stayed Bridge.At last, combined with the results of simulating analysis the construction control system of Shizhou Cable-Stayed Bridge is expatiated in detail, and in every construction stage ,disparities between actual value and theoretical value of the state variation(including controlling point displacement, cable force, controlling section stress) are analyzed and studied, by which the validity of the construction control is validated.The achievements of this paper are valuable for the simulation analysis and construction control of Cable-Stayed Bridge, and it offers a new simplified method for the calculating of the reasonable cable tension and nonlinear effect.更多还原