移动模架施工变宽箱梁线形控制参数敏感性分析研究
发布时间：2018-12-14 20:54
【摘要】：移动模架施工技术因其施工速度快、机械化程度高、占用场地少及不影响通行和通航,在高墩多跨中等跨径(30-50m)桥梁现浇施工中已得到广泛地应用。现阶段该法在等宽截面箱梁桥中得到了大量的应用和研究,而对在变宽异性箱梁桥中的应用和研究尚存不足。本文以一多跨的变宽度连续PC梁桥为依托,运用有限元仿真模拟及正交试验相结合的手段分析施工及成桥后各参数对主梁竖向挠度的影响。提出了各设计参数对桥梁竖向挠度敏感度系数及其计算式,分析变宽度移动模架施施工过程中及成桥各桥梁线形影响因素关于不同截面的系数值,旨在确定各因素的重要性和线形关键控制点,为采用变宽度移动模架法的PC连续梁桥施工线形监控提供理论依据和指导,为今后变宽移动模架法施工的同类桥梁提供经验和参考。具体研究内容和相关结论如下:1)在论述剪力柔性梁格法理论的基础上,对泉州湾跨海大桥秀涂互通主线桥上一五跨一联变宽度PC连续箱梁桥的下行式移动模架施工过程进行仿真分析,验证了梁格法分析异性宽箱梁结构的可靠性。2)为削弱下行式移动模架施工桥梁悬臂端出现上挠现象,且借用斜拉桥斜拉索索力优化的思路,利用未知荷载法确定施工过程中施加在各悬臂端的反顶力值。以施工过程中悬臂端的挠度值±5mm为控制目标,对悬臂端的临时反向顶推力进行了优化设计,寻求合理的顶反力值,使成桥线形更为平顺。3)提出各参数对桥梁竖向挠度敏感系数计算式,分析下行式移动模架施工过程中及成桥后混凝土容重和弹性模量,钢束锚下张拉控制应力,预应力管道的摩阻系数和每米局部偏差对摩擦的影响系数,环境平均相对湿度,加载龄期,同步升降温,移动模架刚度等设计参数对梁体多个节点的竖向挠度影响的敏感性。分析显示:五跨一联变宽变截面连续梁桥下行式移动模架施工结构过程中,第三个悬臂段端部挠度对多数设计参数均较为敏感,为线形控制最敏感点,而中间两跨的3L/4和第一悬臂段端部为较敏感点。4)引用多因素水平的正交试验,对比分析了3种水平7种不同参数对下行式移动模架施工的PC连续箱梁桥主梁最敏感点的挠度影响的敏感性,第三悬臂段端点挠度对锚下张拉控制应力、混凝土的容重、混凝土弹性模量较敏感,其中对锚下张拉控制应力最敏感。
[Abstract]:Because of its high construction speed, high mechanization, less occupied space and no influence on traffic and navigation, the construction technology of moving formwork frame has been widely used in the cast-in-place construction of multi-span and medium-span bridges with high piers (30-50m). At present, the method has been widely used and studied in box girder bridges with equal width section, but the application and research of this method in variable-width and heterosexual box-girder bridges are still insufficient. Based on a multi-span continuous PC girder bridge with variable width, the influence of the parameters on the vertical deflection of the main beam is analyzed by means of finite element simulation and orthogonal test. The sensitivity coefficient of the design parameters to the vertical deflection of the bridge and its calculation formula are put forward, and the coefficient values of the factors affecting the different sections of the bridge are analyzed during the construction of the variable width moving mould frame and the influence factors of the bridge alignment. The purpose of this paper is to determine the importance of each factor and the key linear control points, and to provide theoretical basis and guidance for the linear monitoring of PC continuous girder bridge with variable width moving die frame method. It provides experience and reference for similar bridges constructed by widening moving mould frame method in the future. The specific research contents and related conclusions are as follows: 1) on the basis of the theory of shear flexible beam method, This paper simulates and analyzes the construction process of downlink movable mould frame of PC continuous box girder bridge with variable width and one span on the main line bridge of Xiutu interchange of Quanzhou Bay Crossing Sea Bridge. It verifies the reliability of the beam lattice method to analyze the heterosexual wide box girder structure. 2) in order to weaken the upwarping phenomenon at the end of the cantilever of the downlink movable formwork construction bridge, and borrow the train of thought of cable force optimization of the cable-stayed bridge, In this paper, the method of unknown load is used to determine the value of countertop force applied to each cantilever during construction. Taking the deflection value of the cantilever end 卤5mm as the control target, the temporary reverse thrust of the cantilever end is optimized and the reasonable value of the top reaction force is sought. The formula for calculating the sensitivity coefficient of the parameters to the vertical deflection of the bridge is put forward. The bulk density and elastic modulus of concrete during and after the construction of the downlink movable die frame are analyzed, and the tension control stress under the steel bundle anchor is analyzed. The influence of friction coefficient and local deviation per meter on friction, average relative humidity, loading age, synchronous rising and cooling, stiffness of moving mould frame, and so on, are sensitive to the vertical deflection of beam body. The analysis shows that the end deflection of the third cantilever segment is sensitive to most of the design parameters during the construction of the downlink moving formwork of a continuous beam bridge with variable cross-section and variable cross-section, and is the most sensitive point for linear control. The intermediate two-span 3L/4 and the end of the first cantilever are more sensitive points. 4) the orthogonal test with multi-factor level is used. The sensitivity of three different levels and seven different parameters on the deflection of the main girder of the PC continuous box girder bridge under the downlink moving mold frame is analyzed. The end deflection of the third cantilever section controls the stress under the anchor tension and the bulk density of concrete. The elastic modulus of concrete is more sensitive, among which the tensile stress under anchor is the most sensitive.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.463
本文编号：2379300
[Abstract]:Because of its high construction speed, high mechanization, less occupied space and no influence on traffic and navigation, the construction technology of moving formwork frame has been widely used in the cast-in-place construction of multi-span and medium-span bridges with high piers (30-50m). At present, the method has been widely used and studied in box girder bridges with equal width section, but the application and research of this method in variable-width and heterosexual box-girder bridges are still insufficient. Based on a multi-span continuous PC girder bridge with variable width, the influence of the parameters on the vertical deflection of the main beam is analyzed by means of finite element simulation and orthogonal test. The sensitivity coefficient of the design parameters to the vertical deflection of the bridge and its calculation formula are put forward, and the coefficient values of the factors affecting the different sections of the bridge are analyzed during the construction of the variable width moving mould frame and the influence factors of the bridge alignment. The purpose of this paper is to determine the importance of each factor and the key linear control points, and to provide theoretical basis and guidance for the linear monitoring of PC continuous girder bridge with variable width moving die frame method. It provides experience and reference for similar bridges constructed by widening moving mould frame method in the future. The specific research contents and related conclusions are as follows: 1) on the basis of the theory of shear flexible beam method, This paper simulates and analyzes the construction process of downlink movable mould frame of PC continuous box girder bridge with variable width and one span on the main line bridge of Xiutu interchange of Quanzhou Bay Crossing Sea Bridge. It verifies the reliability of the beam lattice method to analyze the heterosexual wide box girder structure. 2) in order to weaken the upwarping phenomenon at the end of the cantilever of the downlink movable formwork construction bridge, and borrow the train of thought of cable force optimization of the cable-stayed bridge, In this paper, the method of unknown load is used to determine the value of countertop force applied to each cantilever during construction. Taking the deflection value of the cantilever end 卤5mm as the control target, the temporary reverse thrust of the cantilever end is optimized and the reasonable value of the top reaction force is sought. The formula for calculating the sensitivity coefficient of the parameters to the vertical deflection of the bridge is put forward. The bulk density and elastic modulus of concrete during and after the construction of the downlink movable die frame are analyzed, and the tension control stress under the steel bundle anchor is analyzed. The influence of friction coefficient and local deviation per meter on friction, average relative humidity, loading age, synchronous rising and cooling, stiffness of moving mould frame, and so on, are sensitive to the vertical deflection of beam body. The analysis shows that the end deflection of the third cantilever segment is sensitive to most of the design parameters during the construction of the downlink moving formwork of a continuous beam bridge with variable cross-section and variable cross-section, and is the most sensitive point for linear control. The intermediate two-span 3L/4 and the end of the first cantilever are more sensitive points. 4) the orthogonal test with multi-factor level is used. The sensitivity of three different levels and seven different parameters on the deflection of the main girder of the PC continuous box girder bridge under the downlink moving mold frame is analyzed. The end deflection of the third cantilever section controls the stress under the anchor tension and the bulk density of concrete. The elastic modulus of concrete is more sensitive, among which the tensile stress under anchor is the most sensitive.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.463
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