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1、答辩信息中文题目：顶推独塔钢箱梁斜拉桥的索力优化英文题目：Optimum post-tensioning cable forces of cable-stayed bridge of steel-girder and single plyon with incremental launching construction摘 要随着国民经济的快速发展和交通量的日益增长，我国大跨度桥梁的修建规模越来越大， 体系也越来越柔，斜拉桥和悬索桥都是大跨度的索成桥。斜拉桥是大跨径桥梁中最具竞争 力的桥型，根据结构各部分采用的形式和材料的多样性，斜拉桥的施工方法也不尽相同。 钢箱梁因其重量轻，良好的整体性能而
2、被广泛应用于大跨径桥梁中，钢箱梁由于其显著的 剪力滞效应，在施工和营运过程中其受力逐渐引起工程界的广泛关注。 斜拉桥合理成桥状态的确定是衡量斜拉桥设计好坏的重要标准之一。目前国内外许多 学者相继提出了合理成桥状态确定的多种方法，各有优劣，往往单一的方法很难兼顾桥梁 各构件的受力最优。本文在国内外相应研究的基础上，以青银高速济南黄河大桥为工程背 景，对大跨径独塔钢箱梁斜拉桥的剪力滞后效应及合理成桥状态进行分析，主要包括以下 几个方面的内容： 首先，简单总结了斜拉桥顶推施工的特点及适用范围，在基于导主梁模型所确定最 不利工况的基础上，采用混合单元法建立最不利工况的有限元模型，将数值模型、实测结 果
3、进行比较，确定该方法是否可行。 其次，在斜拉桥各种设计理论的基础上，分析了目前各种索力优化方法的优劣，在综 合法的基础上提出了一种更适合于钢箱梁斜拉桥的索力优化方法。首先采用最小弯曲能量 法初定成桥状态，然后采用应力平衡法确定主梁的弯矩可行域，以此作为进一步有约束优 化的约束条件。 再次，在有约束优化方法的基础上，采用惩罚函数将有约束优化问题转化为无约束优 化问题，通过 ANSYS 中的 APDL 语言使优化得以实现。针对钢主梁斜拉桥，采用有别于 混凝土主梁以拉压和弯曲应变能为目标函数的优化方法，而以钢主梁线形平顺、塔的偏位 较小为目标函数进行索力优化，得到成桥状态线形平顺，塔的偏位较小，且混
4、凝土塔和钢 主梁受力合理。 最后，对本文的研究工作进行了总结，给出了研究中的一些结论，并指出了在进一步 研究中有待解决的问题。关键词：斜拉桥；钢箱梁；索力优化；剪力滞；顶推施工；目标函数 ;优化模型AbstractWith the rapid development of the national economy and the increasing rise of the traffic,the scale and number of bridges with long span increase daily in our country,the structure becomes soft
5、er and softer,the Cable-stayed bridge and Suspension bridge are both large span bridge with cable. The Cable-stayed bridge is a competitive bridge type of bridges with long span,according to the diversity of the form and material of the structure,construction method of cable-stayed bridge is endless
6、 also the same.The steel-box girder are widely applied in the super span bridges with its light weight and good performance.The stress of the steel-box girder causes extensive concern of engineering gradually because of significant shear-lag effect.The distributing of internal force of the cable-sta
7、yed bridge at completion stage is one of the important standards to evaluate the design quality.At the present time, there are various methods with there own characteristics to optimize the cable tension, its hard to meet the optimal stress of all structure with a single method. On the background of
8、 Jinan Huanghe River Bridge on Qingdao-Yinchuan Expressway this paper analyses the shear-lag effect and determining the reasonable completed status of Cable-stayed Bridge of steel-box girder with single plyon, including the following several aspects.Firstly,this paper describes the characteristics a
9、nd applicable scope of the incremental launching, confirms the most dangerous condition in the incremental launching construction based on the analysis of model combined the launching nose with main girder and calculates the flat-shear-lageffects coefficient. A FEM modal of the Incremental Launching
10、 of Cable-stayed Bridge with Steel Box Girder is established by ANSYS which proposed by finite mixed element method. Comparing the data we got, the results show that the iternal force is accurate by finite mixed element method which is very important for the similar project.Secondly, by the design t
11、heory of cable-stayed bridge, this paper summarizes and analyzes the present optimization method of the cable,then proposes a new optimization method more suitable for cable-stayed bridge of steel-box girder on the basis of comprehensive method. First, bending energy method is used to determine the
12、initial state,then the stress-balance method is uesd to determine the bending moment of the main beam on the condition of control as the constraint conditions of a further optimize.Again,introducing the principle of optimization,the problem of constrained optimization is transformed into a no-constr
13、ained optimization problem by penalty function,then the optimize comes true through the parameter design language-APDL of ANSYS.For cable-stayed bridge of steel-box girder,this paper adopts the linear smooth of steel-girder and the small deviation of pylon as objective function which is different fr
14、om concrete girders by pressing and bending strain energy.The reresults obtained reveals that the reasonable state of linear smooth of steel-girder and small deviation of plyon,at the same time,the force of concrete pylon and steel girder is reasonable.At the end of the paper, the work in this paper
15、 was summarized and some conclusions about the study were drawn. Besides, the further research problems were indicated in the passage. Key words：cable-stayed bridge; steel-box girder;optimization of cable tension; shear-lag effect; the incremental launching construction; objective function;optimization modal
