大跨径PC连续箱梁桥零号块水化热温度效应及裂缝控制研究

发布时间：2018-04-07 00:25

本文选题：PC箱梁桥　切入点：水化热　出处：《长安大学》2015年硕士论文

【摘要】：近些年来,采用悬臂施工的大跨径预应力混凝土连续箱梁桥得到了广泛应用,该类桥梁由于零号块空间形状复杂,体积大,混凝土强度高,浇筑时可能由于水化热反应而产生较大的温度应力,进而容易出现裂缝,然而零号块是大跨径桥梁悬臂施工的最重要的部件之一,因此零号块的水化热温度效应分析及裂缝控制成了工程建设的重中之重。本论文依托河北老漳河预应力混凝土连续箱梁桥,选取具有代表性的零号块作为研究对象,跟踪观测其在浇筑过程中的温度分布和变化规律,并验证了有限元仿真分析结果。通过仿真分析大跨度PC连续箱梁桥施工时分层浇筑及采取管冷措施的施工时的温度效应,提出裂缝预防对策。本文具体做了以下研究工作:(1)根据现场箱梁零号块断面各测点的温度实测数据,分析零号块各截面温度分布规律,同时拟合零号块各截面温度梯度。(2)对比分析箱梁温度场试验实测数据和有限元理论计算结果,验证有限元仿真计算软件MIDAS FEA对水化热温度效应计算的有效性,可用于估计水化热引起的温度裂缝区域。(3)利用MIDAS FEA计算和模拟采用分层施工和采用管冷措施的零号块施工时混凝土水化热引起的零号块温度场,比较两种工况下温度分布和温度应力值,提出裂缝控制措施。(4)从设计方面及施工方面,提出PC连续箱梁桥零号块防裂控制措施。
[Abstract]:In recent years, long-span prestressed concrete continuous box girder bridges constructed by cantilever have been widely used.However, block zero is one of the most important components in cantilever construction of long-span bridges.Therefore, the analysis of hydration heat temperature effect and crack control of zero block become the top priority of engineering construction.Based on the prestressed concrete continuous box girder bridge of Laozhang River in Hebei Province, this paper selects the representative zero block as the research object, tracks and observes the temperature distribution and variation law during the pouring process, and verifies the results of finite element simulation analysis.Based on the simulation analysis of the temperature effect during the construction of PC continuous box girder bridge with long span and pipe cooling measures, the countermeasures of crack prevention are put forward.In this paper, the following research work is done: (1) based on the measured temperature data of the zero section of box girder, the temperature distribution of each section of zero block is analyzed.At the same time, fitting the temperature gradient of each section of block zero, comparing and analyzing the measured data of the box girder temperature field test and the results of the finite element theory calculation, the validity of the finite element simulation software MIDAS FEA for the calculation of the temperature effect of hydration heat is verified.It can be used to estimate the temperature crack area caused by hydration heat. (3) using MIDAS FEA to calculate and simulate the zero block temperature field caused by hydration heat of concrete under stratified construction and zero block construction with pipe cooling measures,By comparing the temperature distribution and temperature stress value under two working conditions, the crack control measures are put forward. From the aspects of design and construction, the crack control measures of block zero of PC continuous box girder bridge are put forward.
【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】：U448.213;U445.57

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