混凝土拱桥缆索吊装施工的成桥线形控制研究

发布时间：2018-06-19 05:50

本文选题：钢筋混凝土拱桥 + 无支架缆索吊装法　；参考：《重庆交通大学》2014年硕士论文

【摘要】：拱桥，作为最古老的基本桥型，到现在已经有三千多年历史。而钢筋混凝土箱型拱桥，，由于造型宏伟，造价经济，在桥梁工程中得到了广泛应用。无支架缆索吊装施工方法是目前该类型桥梁施工方法中应用最为广泛的一种，由于使用该方法施工过程中桥梁存在结构体系的变化，使桥梁结构在施工过程中和成桥阶段结构内力和位移变得较为复杂。为了使桥梁结构成桥状态下，内力与线性满足设计要求，对其进行施工监控是十分必要的。本文对目前国内外大跨径混凝土拱桥的发展及其现状介绍，总结了现行大跨径混凝土拱桥的施工方法，并详细阐述了无支架缆索吊装施工的施工特点以及吊装系统的组成。在此基础上进一步阐述了在混凝土拱桥吊装过程中施工控制要点及其必要性。进而介绍了在对支架缆索吊装施混凝土拱桥施工监控中应涉及到的主要方面及内容，总结了现有混凝土拱桥缆索吊装施工中扣索索力及其线形计算方法，并对缆索吊装拱桥施工过程中线形调整方法进行了说明。本文以重庆市两江新区龙门大桥为依托工程，介绍了龙门大桥的工程背景及概况，并根据其吊装施工方案明确在该桥梁施工监控中的监控要点。本文通过建立龙门大桥的有限元计算模型，在对龙门大桥线形控制过程中进行了如下工作： ①本文通过综合考虑拱圈合拢后预拱度设置的各种相关因素，给出了无支架缆索吊装混凝土拱桥预拱度计算方法，结合拢门大桥工程实例，通过建立其成桥后有限元计算模型，计算得出各影响因素包括成桥后静力恒载、活载、温降以及结构收缩徐等对其拱圈线形的影响，根据前述公式，计算得出合理拱圈预拱度值。并根据该预拱度值通过施工放样对拱圈预制线形进行监控。②本文通过综合考虑拱圈在吊装施工过程中可能对拱圈线形产生影响的各种相关因素，结合拢门大桥工程实例，定量计算各影响因素对其拱圈线形的影响，其中包括浪风索设置和风荷载对拱圈横向线形的影响，浪风索设置、风荷载共同作用下塔架偏移量、吊装过程中拱箱节段设置预抬量以及拱桥合拢固结后松索顺序对拱圈纵向线形的影响。通过设置各因素对拱圈线形的影响值的反向值得出施工预抬量设置值。③本文也对浪风索在不同初张力控制量设置下以及拱桥合拢固结后不同松索顺序对拱圈线形的影响进行了横向研究，得出了不同浪风索初张力以及不同松索顺序对拱圈线形的影响，为类似桥梁提供参考。④通过综合考虑以上计算所得各影响因素对桥梁线形的影响，本文得出了龙门大桥拱圈横向及纵向线形监控理论依据，以此指导龙门大桥实际施工过程及监控。
[Abstract]:Arch bridge, as the oldest basic bridge, has a history of more than three thousand years. Reinforced concrete box arch bridge is widely used in bridge engineering because of its magnificent shape and economical cost. The construction method of cable hoisting without support is one of the most widely used construction methods of this type of bridge at present, because of the structural system change in the construction process of the bridge with this method. It makes the internal force and displacement of the bridge structure more complicated during the construction process and the bridge completion stage. In order to make the internal force and linearity of the bridge structure meet the design requirements, it is necessary to monitor the construction of the bridge structure. This paper introduces the development and present situation of long span concrete arch bridge at home and abroad, summarizes the current construction method of long span concrete arch bridge, and expounds in detail the construction characteristics of cable hoisting without support and the composition of hoisting system. On this basis, the construction control points and its necessity in the hoisting process of concrete arch bridge are further expounded. Furthermore, this paper introduces the main aspects and contents that should be involved in monitoring and controlling the construction of concrete arch bridge with support cable hoisting, and summarizes the cable buckling force and its linear calculation method in cable hoisting construction of existing concrete arch bridge. The alignment adjustment method in the construction process of cable-mounted arch bridge is explained. Based on the Longmen Bridge in Liangjiang New District of Chongqing, this paper introduces the engineering background and general situation of Longmen Bridge, and according to its hoisting construction plan, it makes clear the main points of monitoring and control in the construction of the bridge. In this paper, by establishing the finite element model of Longmen Bridge, the following work has been done in the process of linear control of Longmen Bridge: (1) in this paper, the factors related to the setting of pre-arch degree after the closure of arch ring are considered synthetically. In this paper, the calculation method of pre-arched degree of concrete arch bridge without support cable crane is given. By establishing the finite element calculation model after completion of the bridge, the calculation results show that the influencing factors include static dead load and live load after completion of the bridge. The effect of temperature drop and structural shrinkage and creep on the arched ring alignment is obtained. According to the above formula, the reasonable arch ring pre-arched degree is calculated. According to the pre-arch value, the preform of arch ring is monitored by construction lofting. 2. By considering comprehensively all kinds of relevant factors which may affect the shape of arch ring in the process of hoisting construction, this paper combines with the engineering example of Guanmen Bridge. Quantitative calculation of the influence factors on the shape of the arch ring, including the installation of wind cable and the influence of wind load on the transverse alignment of arch ring, the installation of wind cable and the offset of tower under the combined action of wind load, wind load and wind load, In the process of hoisting, the influence of the pre-lifting of arch box segment and the sequence of loosening cable after the closure and consolidation of arch bridge on the longitudinal alignment of arch ring is discussed. By setting the reverse value of the influence value of various factors on the arch ring alignment, this paper also sets the value of pre-lifting value of construction. 3. 3. This paper also deals with the arch ring line in different initial tension control settings and after the arch bridge is closed and consolidated with different loose cable sequence. The influence of shape is studied horizontally. The influence of different initial tension of wave wind cable and different order of loosening cable on the shape of arch ring is obtained, which provides reference for similar bridges. In this paper, the theoretical basis of horizontal and longitudinal linear monitoring of arch ring of Longmen Bridge is obtained to guide the actual construction process and monitoring of Longmen Bridge.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4;U448.22

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