大跨径下承式钢管混凝土系杆拱桥吊杆张拉力控制优化分析

发布时间：2018-04-05 19:07

本文选题：钢管混凝土拱桥　切入点：有限元仿真分析　出处：《兰州交通大学》2014年硕士论文

【摘要】：拱桥作为一种古老的桥型，在我们国家的桥梁史上留下了光辉的历史。钢管混凝土拱桥则是基于对钢管混凝土新技术应用于古代拱桥中发展起来的新型拱桥。近年来，异军突起的钢管混凝土系杆拱桥，是60-200m主跨径范围内非常具有竞争力的桥型之一。吊杆是重要的结构在下承式系杆拱桥中，桥梁的受力状况受吊杆张拉力影响较大，尤其是对主梁和拱肋。本文的工程背景为沈丹线太子河系杆拱桥，利用MIDAS CIVIL计算软件对全桥建立了有限元模型，，并且对该模型进行了有限元分析。吊杆的张力根据力的平衡法确定，确保了拱肋和主梁有更理想的恒载弯矩分布，吊杆的受力更均匀。利用倒装法计算出施工阶段的吊杆初始张力。通过优化调整吊杆张拉力，令主梁以及拱肋的内力更趋于合理。对成桥前后吊杆的受力变化进行了对比，看出活载使得吊杆张力增加，索力有大概一致的增幅，活载对吊杆的影响较大。本文的主线是系杆拱桥吊杆力张拉调整，利用三种不同的方法对吊杆力优化调整并从不同的角度进行了比较分析，这三种方法分别是刚性吊杆法、一次落架法、刚性支承梁法。根据该桥的实际情况以及计算结果，不论从设计还是施工上，一次落架法都能够满足要求；接着对太子河系杆拱桥的吊杆张拉顺序方案1、方案2作对比计算分析，通过张拉顺序方案的比较，得出方案2更为合理可靠。最后对索力测试原理进行了介绍，重点介绍了频率法。该桥的索力测试应用了频率法。通过对吊杆索力实测值和本阶段目标索力值比较，相对误差均在10%以内，满足落架条件，可以进行系梁落架。待落架完成后，测试了各个吊杆的索力，并且通过与设计值的比较确定是否调索，以保证每根吊杆的索力均没有超过设计误差的允许范围。根据索力的测试结果并根据设计院提供的目标索力进行了两次调索，由调索完成后的结果可以看出，全桥吊杆力控制均匀，每根吊杆的目标值与实际测量值吻合较好，目标值与实际测量值的误差都在合理的误差范围以内，从全桥和局部来看都是理想的，满足设计对吊杆力的要求。
[Abstract]:As an ancient bridge type, arch bridge has left a glorious history in the history of bridges in our country.Concrete-filled steel tubular (CFST) arch bridge is a new arch bridge based on the application of new concrete filled steel tube (CFST) technology to ancient arch bridges.In recent years, Concrete-filled steel tubular tied arch bridge is one of the most competitive bridges in the range of 60-200 m main span.The suspension rod is an important structure in the through tie arch bridge, the stress condition of the bridge is greatly affected by the tension of the suspender, especially to the main beam and arch rib.In this paper, the finite element model of the whole bridge is established by using MIDAS CIVIL software, and the finite element analysis of the model is carried out.The tension of the suspender is determined by the method of force balance, which ensures that the arch rib and the main beam have more ideal distribution of dead load bending moment, and the force of the suspender is more uniform.The initial tension of the suspender in the construction stage is calculated by using the inversion method.By optimizing the tension of the suspender, the internal force of the main beam and arch rib is more reasonable.By comparing the stress changes of the suspenders before and after the bridge, it is found that the live load increases the tension of the suspenders, and the cable force increases roughly, and the live load has a great influence on the suspenders.The main line of this paper is the tension adjustment of suspenders of tied arch bridge. Three different methods are used to optimize and analyze the force of suspenders. The three methods are rigid suspension method, primary fall method and rigid support beam method.According to the actual situation of the bridge and the result of calculation, the single drop frame method can meet the requirements in both design and construction.Through the comparison of tensioning sequence scheme, it is concluded that scheme 2 is more reasonable and reliable.Finally, the principle of cable force measurement is introduced, and the frequency method is emphasized.The frequency method is used to test the cable force of the bridge.The relative error is less than 10% by comparing the measured value of suspension cable force with the value of target cable force at this stage, which satisfies the condition of falling frame, and can be used to tie beam drop frame.After the drop frame is finished, the cable force of each suspender is tested, and whether the cable is adjusted or not is determined by comparing with the design value to ensure that the cable force of each suspension does not exceed the allowable range of the design error.According to the test results of the cable force and the target cable force provided by the design institute, the cable is adjusted twice. From the results of the cable adjustment, it can be seen that the force of the suspension rod of the whole bridge is controlled evenly, and the target value of each suspender is in good agreement with the actual measured value.The error between the target value and the actual measurement value is within the reasonable error range, which is ideal from the whole bridge and the local point of view, and meets the requirements of the design for the suspender force.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.225

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