空腹式梯形箱梁连续刚构桥施工过程结构分析与监测

发布时间：2018-03-09 23:39

本文选题：空腹式　切入点：刚构桥　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：空腹式梯形箱梁连续刚构桥的造型新颖,具有拱桥和连续刚构桥的力学性能特点。以涪江一桥为依托工程,建立该空腹式梯形箱梁连续刚构桥的有限元模型,对桥梁结构各个施工阶段的内力、应力以及施工阶段稳定性问题进行了理论分析,并由此确定了施工重点监测点,通过监控实测并结合理论值指导施工。有如下结论： (1)阐述了预应力混凝土连续刚构桥的模拟施工阶段结构计算方法,即正装法和倒装法,经过分析比较,确定了模拟空腹式梯形箱梁连续刚构桥的施工阶段采用正装计算法,能够明显减小计算量。 (2)以涪江一桥为依托工程,按照现有施工组织设计建立了有限元模型,采用了正装法模拟计进行分析计算,分析了该桥在各个施工阶段在静荷载作用下内力的分布情况和各梁段可能出现的最大内力,分析结果表明各阶段在静荷载作用下内力分布合理,在整个施工过程中各梁段的最大内力均在规范限值内,结构是安全可靠的。 (3)分析了主梁最大悬臂状态和成桥状态结构的稳定性!结果表明成桥状态整体结构弹性屈曲安全系数为81.4,失稳模态为主梁竖向弯曲失稳；最大悬臂状态整体结构弹性屈曲安全系数为67.6,失稳模态为桥墩侧向弯曲失稳。 (4)施工过程中对各施工阶段的应力进行了监测,分析了三个主要控制截面的应力,结果表明主要控制截面的应力实测值和理论计算值的变化趋势吻合度较好,只有个别测点因混凝土龄期、收缩徐变以及温度等因素的影响表现出较大的波动性,但整体上是符合荷载施加时产生的应力分布规律。 (5)通过对成桥后的标高进行测量,发现成桥线形与设计理想线形吻合度较好,大部分测点与设计值之间的误差均在20mm以内。
[Abstract]:The continuous rigid frame bridge with hollow trapezoidal box girder is novel in shape and has the characteristics of mechanical properties of arch bridge and continuous rigid frame bridge. The finite element model of the continuous rigid frame bridge of the hollow trapezoid box girder is established based on the Fujiang first bridge. In this paper, the internal force, stress and stability of the bridge structure in each construction stage are theoretically analyzed, and the key monitoring points of construction are determined. The construction is guided by monitoring and measuring and combining with the theoretical value. The conclusions are as follows:. This paper expounds the calculation methods of the structure of prestressed concrete continuous rigid frame bridge in the simulated construction stage, that is, the normal loading method and the inversion method. Through the analysis and comparison, it is determined that the construction stage of the continuous rigid frame bridge with simulated empty web trapezoidal box girder is based on the normal fitting calculation method. The computational complexity can be reduced obviously. Based on the Fujiang Bridge, the finite element model is established according to the existing construction organization design, and the analysis and calculation are carried out by using the formal dress method simulator. The distribution of internal force under static load and the maximum internal force in each section of beam are analyzed in this paper. The results show that the distribution of internal force in each stage under static load is reasonable. In the whole construction process, the maximum internal force of each beam section is within the limit value of the code, and the structure is safe and reliable. The stability of the maximum cantilever state and the bridge state structure of the main beam is analyzed. The results show that the safety factor of elastic buckling of the whole structure is 81.4, the main mode of instability is the vertical bending instability of the beam, and the safety factor of elastic buckling of the whole structure under the maximum cantilever state is 67.6, and the instability mode is the lateral bending instability of the pier. 4) during the construction process, the stress of each construction stage is monitored, and the stress of the three main control sections is analyzed. The results show that the variation trend of the measured stress values and the theoretical calculated values of the main control sections is in good agreement. Only a few measuring points show great fluctuation due to concrete age, shrinkage, creep and temperature, but as a whole accord with the law of stress distribution under load. 5) by measuring the elevation of the bridge, it is found that the alignment between the completed bridge and the ideal design is good, and the error between most of the measured points and the design value is less than 20mm.
【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

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