千米级多塔连跨悬索桥中间塔适宜刚度及连跨效应研究

发布时间：2018-03-26 08:15

本文选题：桥梁工程　切入点：多塔连跨悬索桥　出处：《北京交通大学》2017年博士论文

【摘要】：千米级多塔连跨悬索桥可有效减小锚碇尺寸、大幅降低岸线和土地资源占用、降低航道资源占用、减少深水基础工程量和船只撞击概率,具有显著的经济、环保效益,是跨越宽阔水域的最佳桥型之一,发展前景广阔。由于在传统两塔悬索桥的基础上增设了中间塔,千米级多塔连跨悬索桥的结构行为特性将发生很大的变化,“中间塔效应”和“连跨效应”是千米级多塔连跨悬索桥工程应用中需要重点研究的两个核心问题。目前,“中间塔效应”和“连跨效应”的力学特征、影响规律尚不明确,计算分析方法需进一步深化。本文以泰州长江公路大桥的工程建设为背景,依托“十一五”国家科技支撑计划重点项目“多塔连跨悬索结构及工程示范”(2009BAG15B00),重点针对多塔连跨悬索桥的中间塔适宜刚度、偏位计算方法、连跨效应等开展研究。主要工作如下:(1)通过数值分析的方法,研究了不同塔梁连接、中间塔刚度变化对三塔、四塔、五塔悬索桥在活载作用下的中间塔效应,分析了中间塔刚度变化对跨中挠度和主缆抗滑移系数的影响规律。在此基础上,进一步提出了中间塔适宜刚度的取值方法,并讨论了-《公路悬索桥设计规范》(JTG/TD 65-05-2015)中关于结构容许变形限值、抗滑移安全系数参数取值对多塔连跨悬索桥的适用性。(2)基于挠度理论,建立了多塔悬索桥桥塔简化受力模型,提出了塔顶纵向水平换算刚度解析计算方法,推导了桥塔偏位的简化计算公式。采用该简化计算公式,分析了主缆矢跨比、边中跨比、桥塔刚度、主缆刚度和恒载等参数对多塔悬索桥中间塔塔顶最大纵向偏位的影响规律。(3)基于结构影响线分析方法,通过有限元分析,研究了不同桥塔刚度、缆-梁连接及塔-梁连接型式等结构参数对三塔悬索桥结构性能的影响。进而将桥塔数量扩展到四塔至六塔,进一步探讨了大跨度多塔悬索桥的连跨效应特征。(4)开展1: 80三塔连跨悬索桥的静动力特性模型试验,分析了三塔连跨悬索桥施工阶段和成桥阶段的结构特征和受力特性。在此基础上,建立了五塔悬索桥试验模型,分析了五塔连跨悬索桥成桥阶段受力特征和多塔连跨效应,为数值分析结果和解析计算的结果的验证提供数据支持。通过上述研究工作,揭示了中塔刚度、塔梁连接、主缆垂跨比、边中跨比、恒载变化等对中塔效应的影响规律,提出了综合考虑加劲梁竖向挠度控制和主缆抗滑移的中间塔适宜刚度区间取值方法,推导了塔顶纵向水平偏位的简化计算公式,掌握了多塔连跨悬索桥“连跨效应”特征。研究成果为突破千米级多塔连跨悬索桥计算分析和设计建造的关键制约、支撑该类工程的建设起到了重要作用。
[Abstract]:Multi-tower and multi-span suspension bridges of kilometer scale can effectively reduce the Anchorage size, greatly reduce the occupation of shoreline and land resources, reduce the occupation of waterway resources, reduce the quantity of deep-water foundation works and the probability of ship collision, and have remarkable economic and environmental benefits. Is one of the best bridges across wide waters, and has a bright future. Because of the addition of the middle tower to the traditional two-tower suspension bridge, The structural behavior of the multi-tower and span suspension bridges of kilometer scale will change greatly. The "intermediate tower effect" and "continuous span effect" are the two key problems that need to be studied in the engineering application of the multi-tower continuous span suspension bridge of the kilometer scale. The mechanical characteristics of "intermediate tower effect" and "continuous span effect", The law of influence is not clear, and the method of calculation and analysis needs to be further deepened. This paper takes the construction of Taizhou Changjiang River Highway Bridge as the background. Relying on the key project of "Multi-tower continuous span suspension structure and engineering demonstration" in the 11th Five-Year Plan of the National Science and Technology support Plan, this paper focuses on the appropriate stiffness of the middle tower of the multi-tower continuous span suspension bridge, and the calculation method of the deflection position, especially in view of the appropriate stiffness of the middle tower of the multi-tower continuous span suspension bridge. The main work is as follows: 1) through numerical analysis, the effects of different tower girder connections and stiffness changes of middle towers on three towers, four towers, five towers suspension bridges under live load are studied. The influence of the stiffness of the intermediate tower on the midspan deflection and the anti-slip coefficient of the main cable is analyzed. On the basis of this, the method of determining the appropriate stiffness of the intermediate tower is put forward. The applicability of JTG / TD65-05-2015) about the allowable deformation limit and the safety factor of anti-slip to multi-tower and multi-span suspension bridge is discussed. Based on the deflection theory, the simplified stress model of the tower of multi-tower suspension bridge is established. In this paper, an analytical method for calculating the longitudinal horizontal conversion stiffness of the tower is presented, and a simplified formula for calculating the deflection of the bridge tower is derived. The main cable span ratio, the side to middle span ratio, the bridge tower stiffness are analyzed by using the simplified calculation formula. The influence of the main cable stiffness and dead load on the maximum longitudinal deflection of the top of the middle tower of a multi-tower suspension bridge is studied. Based on the structural influence line analysis method, the stiffness of different towers is studied by finite element analysis. The influence of structural parameters such as cable-beam connection and tower-beam connection on the structural performance of three-tower suspension bridge. Further, the number of towers is extended to four to six towers, The characteristics of continuous span effect of long-span multi-tower suspension bridge are further discussed. (4) the static and dynamic model test of 1: 80 three-tower suspension bridge is carried out. The structural and mechanical characteristics of the three-tower continuous span suspension bridge during the construction and completion stages are analyzed. Based on this, the test model of the five-tower suspension bridge is established, and the stress characteristics and the multi-tower continuous span effect of the five-tower continuous span suspension bridge are analyzed. This paper provides data support for the verification of numerical analysis results and analytical calculation results. Through the above research work, the effects of mid-tower stiffness, tower beam connection, main cable vertical span ratio, side-to-middle span ratio, dead load change on the mid-tower effect are revealed. In this paper, a method for determining the appropriate stiffness interval of the intermediate tower considering the vertical deflection control of stiffened beam and the resistance of the main cable to sliding is put forward, and the simplified formula for calculating the vertical horizontal deflection of the tower top is derived. The characteristics of "continuous span effect" of multi-tower and multi-span suspension bridges are grasped. The research results play an important role in breaking through the key constraints of calculation, analysis, design and construction of multi-tower and multi-span suspension bridges of kilometer scale, and supporting the construction of this kind of projects.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U448.25

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