大吨位连续刚构桥转体施工控制及稳定性研究

发布时间：2018-07-10 02:33

本文选题：连续刚构 + 参数敏感性　；参考：《兰州交通大学》2016年硕士论文

【摘要】：桥梁的转体施工拥有诸多优点,并能很好的适应现代交通技术发展的需要,因此桥梁转体施工工艺被广泛采用。但是,针对每个不同的转体桥,转体施工的控制和力学特性不尽相同。因此,本文依托某(68+116+68)m连续刚构转体桥为工程背景,对该桥影响主梁线形和内力的参数及转体施工桥梁的稳定性进行研究。主要研究工作如下:(1)建立Midas Civil全桥有限元模型,分别计算并提取合龙前安装防护棚与合龙后安装防护棚两种施工顺序下主梁的理论预拱度值,对比分析防护棚安装顺序对主梁线形的影响,结合现场实际情况,确定最优的施工顺序。同时结合实际施工中可能出现的情况,运用控制变量法,对影响本桥线形和内力的混凝土容重、预应力张拉力、弹性模量、单侧超重及合龙时间延长等参数进行了敏感性分析,结果表明混凝土容重、预应力张拉力对本桥施工精度的控制有显著的影响,施工时应严格控制参数值的变化,确保桥梁成桥后的线形与内力与设计值相符。(2)以某(40+64+40)m转体桥施工为例,用球铰转动法对该桥进行了平衡称重试验,根据现场实际平衡称重试验为(68+116+68)m连续刚构转体桥提出了合理的平衡称重试验方案。通过对现场实测数据分析,总结出每个测试墩在首次称重时,达到临界荷载值时所需的顶力加载级数较少,为转体桥测试墩首次称重顶力加载级数控制提供了有价值的经验。(3)桥梁转体前和转体过程中,考虑风荷载及不平衡重的影响,通过解析法分别计算了不同球铰摩阻系数下桥梁的安全稳定性系数。得到了风荷载单独作用下桥梁稳定性系数很高,而且不平衡重量对桥梁结构的安全稳定性影响很大。同时通过对比分析不同球铰摩阻系数下转体桥安全稳定性系数,提出了根据现场平衡称重试验测出的静摩阻系数值确定转体配重方案的方法,确保桥梁转体时纵向安全稳定。(4)应用ANSYS有限元软件,分别计算了转体前自重作用下上球铰、下球铰、下承台混凝土的局部应力及撑脚位移和匀速转动时主梁、桥墩与主梁连接处的应力响应。得到了自重作用下,各构件的强度均能满足规范要求;匀速转动时,不同的转动角速度对主梁、桥墩与主梁连接处的应力影响较小。
[Abstract]:The bridge rotary construction has many advantages and can meet the needs of modern traffic technology development. Therefore, the bridge rotary construction technology is widely used. However, the control and mechanical properties of rotary construction are different for each different rotary bridge. Therefore, based on the engineering background of a (68,11668) m continuous rigid frame rotary bridge, this paper studies the parameters that affect the alignment and internal force of the main beam and the stability of the rotating bridge. The main research works are as follows: (1) the finite element model of Midas Civil full bridge is established to calculate and extract the theoretical pre-camber value of the main beam under the two kinds of construction sequence respectively. The influence of installation sequence of protective shed on the alignment of main beam is analyzed, and the optimal construction sequence is determined in combination with the actual situation on the spot. At the same time, combined with the possible situation in actual construction, the sensitivity analysis of the parameters such as concrete bulk density, prestressed tension force, elastic modulus, unilateral overweight and lengthening of closing time, which affect the linear and internal force of the bridge, is carried out by using the control variable method. The results show that the concrete bulk density and prestress tension have a significant effect on the control of the construction precision of the bridge, and the change of the parameters should be strictly controlled during the construction. It is ensured that the alignment and internal force of the bridge are in accordance with the design value. (2) taking the construction of a (4064 40) m rotary bridge as an example, the balance weighing test of the bridge is carried out by using the ball hinge rotation method. According to the actual balance weighing test in the field, a reasonable balance weighing test scheme is put forward for the (68 116 68) m continuous rigid frame rotating bridge. Based on the analysis of the field measured data, it is concluded that when each test pier reaches the critical load value for the first time, it needs less top force loading series. It provides valuable experience for the series control of the first load of the test piers. (3) the influence of wind load and unbalanced weight is considered before and during the rotation of the bridge. The safety and stability coefficients of bridges with different ball hinge friction coefficients are calculated by analytical method. It is concluded that the bridge stability coefficient is very high under the action of wind load alone, and the unbalance weight has a great influence on the safety stability of the bridge structure. At the same time, by comparing and analyzing the safety and stability coefficient of the rotary bridge under different ball hinge friction coefficient, the method of determining the rotating weight scheme is put forward according to the static friction coefficient value measured by the field balance weighing test. (4) by using ANSYS finite element software, the local stress of the upper ball hinge and the concrete under the bottom cap, the displacement of the supporting foot and the main beam with uniform rotation speed are calculated respectively by using ANSYS finite element software, which is used to ensure the longitudinal safety and stability of the bridge. The stress response at the junction between the pier and the main beam. Under the action of self-weight, the strength of each member can meet the requirements of the specification, and when the rotation speed is constant, the influence of different rotation angular velocity on the stress of the main beam, the connection between the pier and the main beam is relatively small.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.4

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