【作者】 丁琦；

【导师】 虞庐松；

【作者基本信息】 兰州交通大学 ， 防灾减灾工程及防护工程， 2006， 硕士

【摘要】 近年来，随着我国大跨径拱桥的不断发展，拱肋无支架缆索吊装的施工方法得到了越来越多的应用，而拱肋的合理成拱状态的计算也越来越成为施工控制的关键。大跨度拱桥的拱肋吊装是一个复杂的过程，为了保证最终的成桥线形和受力状态满足设计要求，需要采用施工控制仿真计算。而且大跨度拱桥作为生命线工程之一，它的破坏会造成震后救灾工作的巨大困难，使次生灾害加重，因此，对大跨度拱桥进行抗震分析是十分必要的。本文以某大跨外倾拱桥为工程背景，进行了以下工作：(1)以大型分析软件ANSYS为平台，采用正装分析法，模拟拱桥拱肋的吊装过程，编制相应的ANSYS命令流程序。(2)将“单元生死技术”引入到拱桥施工过程的模拟分析中，一次性建好全桥吊装结构模型。在以后每阶段的结构分析中，通过生死开关来杀死或激活相应的施工节段，以此来实现对整个施工过程的模拟计算。(3)针对千斤顶斜拉扣挂体系调索次数与方法限制的难题，将最优化计算理论引入到拱桥拱肋吊装计算中，采用一阶分析法来确定拱桥的合理施工状态，求出各施工状态的扣索索力和拱肋吊装高度，模拟拱肋的拼装过程。(4)在基于优化理论计算合理扣索力的基础上，利用修改目标函数，研究扣索用料最少的扣索优化设计。(5)针对该大桥，建立合理的计算模型，分析结构体系的动力特性，并采用反应谱法和弹性时程分析法对该桥进行抗震分析。得到以下一些主要结论：(1)将“单元生死技术”引入到大跨度拱桥拱肋施工过程的模拟分析中，解决了计算分析中繁琐的反复建模问题，从而使得该桥的施工控制结构分析过程程序化、简单化。(2)将最优化的计算理论引入到大跨度拱桥拱肋节段吊装及拱肋线形和内力调整的扣索索力计算中，所计算出的索力能确保结构的受力状态始终处在安全范围内，架设和调整后的拱肋线形符合设计期望，而且索力的计算精度较高，能直接作为施工控制依据，避免了施工中繁琐的调索工作。(3)利用多步优化计算方法，既有效的确定拱肋的合理拱轴线形，同时节省了扣索用料，减小了施工费用，获得了更佳的经济效益。(4)建立了某大跨度外倾拱桥的动力计算模型，分析了该桥的动力特性，并利用反应谱方法和弹性时程法计算了该桥各主要截面的地震力。更多还原

【Abstract】 Along with the ceaseless development of large span arch bridges in our country, cablehanging construction without scaffolding of arch rib obtains more and more applications inrecent years, and the analysis of reasonable arch rib closure state also more and more becomesthe key of the construction control. The arch rib hanging construction of large span archbridge is a complex process, in order to guarantee the final bridge line-shape and the forcingcondition satisfying the design request, it needs to use the construction control simulationcalculation. As one of lifeline projects, the destruction of large span arch bridges creates hugedifficulty to earthquake relief, aggravates parasitic infestation, so it is very necessary to carryon the aseismic analysis of large span arch bridge.This article take some large span outside leaning arch bridge as the project background,carried on the research as follows:(1)This thesis takes large-scale analysis software ANSYS as the platform, and uses thenormal direction analysis method, simulates arch rib hanging construction process of the archbridge, works out the corresponding ANSYS order flow.(2) This thesis introduces "the element birth and death technology" into the arch bridgeconstruction simulation analysis process, builds up the whole bridge hanging constructionmodel at one time. In the later each stage structure analysis, kills or alives correspondingconstruction section through the life and death switch, so as to complete simulation analysisof the entire construction process.(3) Aiming at the difficult problem of adjusting cable times and the method limit in jackcable-stayed suspension system, this thesis introduces the optimum analysis theory into archrib hanging construction computation of arch bridge, uses the first order analysis method todetermine the arch bridge reasonable construction condition, analyzes the cable force and archrib hanging elevation in each construction condition, simulates the arch rib hangingconstruction process.(4) On the basis of analyzing reasonable cable force with optimum analysis theory, Thisthesis amends the objective function, studies cable optimum design of the lowest materialconsumption.(5) This thesis establishes the reasonable analysis model of this bridge, calculates thestructure dynamic property, and carries on the seismic analysis to this bridge with responsespectrum method and elastic time-history method.Some conclusions can be drawn as follows:(1) By introducing "the element birth and death technology" into the arch bridge construction simulation analysis process, solves the tedious repeated modeling problem inanalysis, make the process of construction control analysis of the bridge formalization andmore simple.(2) By introducing the optimum computation theory into arch rib hanging constructioncomputation of arch bridge, the calculated cable force can guarantee the structure forcingcondition always to be in the bound of safety, the constructed and adjusted arch rib line-shapeconformed to the design expectation, moreover the computed cable force has high precision,and it can be the basis of construction control directly, avoided the tedious adjusting cablework in construction.(3) Using multiple steps optimizations analysis method, effectively confirms the reasonablearch rib axis line-shape, at the same time, economizes the cable materials, reduces theconstruction charges, obtaines the better economic efficiency.(4) Establishes the dynamic computation model of some large span outside leaning archbridge, analyzes the dynamic property of the bridge, and analyzes each main section seismicforce of this bridge with response spectrum method and elastic time-history method.更多还原