独塔斜拉桥换索施工控制研究

发布时间：2018-04-26 21:16

本文选题：斜拉桥 + 换索方案　；参考：《浙江大学》2014年硕士论文

【摘要】：斜拉索作为斜拉桥最主要受力构件之一,常常因为工作环境恶劣、受力状态不合理及运营管理不善等原因,容易导致PE套管破裂腐蚀、钢绞线(或钢丝)锈蚀严重甚至拉索突然断裂等病害,导致拉索承载能力降低,严重威胁着斜拉桥的安全使用。为了对损坏的斜拉索进行修复并恢复桥梁承载能力,国内外纷纷对此类斜拉桥采取了斜拉索更换措施。但目前换索施工的理论研究远远滞后于工程实际,为此,本文以上虞市人民大桥换索工程为背景,选择斜拉桥换索过程中的关键问题进行了研究,研究内容如下： (1)在恢复斜拉桥换索前成桥状态的基础上,分别建立了逐根换索、正对称更换2根拉索和反对称更换2根拉索三种典型的独塔斜拉桥拉索更换方案的有限元模型,通过比较三种换索方案下的斜拉索索力增量、桥面线形、主梁应变等桥梁受力指标变化量得到了更优的换索方案,即正对称更换2根斜拉索；然后通过比较换索施工阶段主梁弯曲应变能的大小,得到了更优的换索施工顺序,即从短索向长索更换斜拉索。 (2)把阻尼减震器对拉索振动的影响考虑到拉索体系振动微分方程中,通过有效模拟阻尼减震块的力学特性,建立了考虑阻尼器影响的斜拉索的振动能量方程,推导出了拉索索力与其自振频率的关系,即索力计算公式；把该公式应用到人民大桥斜拉索索力计算结果表明,新公式比传统公式计算误差更小,更能满足实际工程的精度要求。 (3)通过比较各国关于温度荷载的计算规范,选择出了合适于人民大桥的温度计算模式,用有限元软件MIDAS/Civil对人民大桥进行了温度效应分析,结果表明体系温差和桥塔温度梯度对桥梁内力影响较小,而索梁(塔)温差和主梁温度梯度对桥梁内力影响较大；同时提出了在换索施工监控时温度对索力监测、主梁应力监测影响的初步修正建议。
[Abstract]:As one of the main stress components of cable-stayed bridge, the cable often leads to the rupture and corrosion of PE casing because of the bad working environment, unreasonable stress condition and poor operation management, etc. The serious corrosion of steel strands (or wires) and even the sudden breakage of cables lead to the reduction of cable bearing capacity, which seriously threaten the safe use of cable-stayed bridges. In order to repair the damaged cable-stayed cables and restore the bearing capacity of the bridges, the cable-stayed bridges have been replaced one after another at home and abroad. However, the theoretical study of cable replacement construction lags far behind the engineering practice. In this paper, the key problems in cable replacement process of cable-stayed bridge are studied based on the cable changing project of Shangyu people's Bridge. The research contents are as follows: 1) on the basis of restoring the state of the cable-stayed bridge before cable replacement, the finite element models of three typical cable-stayed bridge cable replacement schemes, one by one, two cables symmetrically and two cables are established, respectively. By comparing the force increment of cable-stayed cable, the line shape of bridge deck and the strain of main beam, the better scheme of cable exchange is obtained, that is, two cable-stayed cables are replaced symmetrically. Then by comparing the bending strain energy of the main beam in the stage of cable replacement construction, a better sequence of cable exchange construction is obtained, that is, replacing the stay cable from short cable to long cable. (2) the effect of damping damper on cable vibration is taken into account in the vibration differential equation of cable system. By effectively simulating the mechanical characteristics of damping damper, the vibration energy equation of stay cable considering the influence of damper is established. The relation between cable force and its natural vibration frequency is derived, that is, the formula of cable force, which is applied to the calculation of cable force of people's Bridge, shows that the new formula has less error than the traditional formula. More can meet the actual engineering accuracy requirements. 3) by comparing the calculation codes of temperature loads in different countries, the temperature calculation model suitable for the people's Bridge is selected, and the temperature effect of the people's Bridge is analyzed by using the finite element software MIDAS/Civil. The results show that the temperature difference of the system and the temperature gradient of the bridge tower have little influence on the internal force of the bridge, while the temperature difference of the cable beam (tower) and the temperature gradient of the main beam have great influence on the internal force of the bridge. The preliminary correction suggestion of the influence of the main beam stress monitoring.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27;U445.4

【参考文献】