预应力混凝土T型梁温度分布分析

发布时间：2018-04-10 03:14

本文选题：混凝土T型梁　切入点：水化热温度　出处：《东北林业大学》2014年硕士论文

【摘要】：随着中国国民经济持续稳定的增长,交通运输业蓬勃兴起,需要修建的桥梁数量巨大,桥梁建设行业空前的繁荣。在众多的桥型中,预应力混凝土T型梁桥以其结构刚度大、抗扭能力强、整体性好、行车平顺等突出优点常被选为最佳桥型方案。但是近年来,国内外的许多预应力混凝土连续T型梁桥在使用过程中均出现了不同程度的裂缝。这一现象引起了国内外桥梁专家和科研人员的重视,这些学者证明了桥梁结构产生裂缝的主要原因是温度应力。混凝土导热性能较差,在温度效应作用下,桥梁结构产生较大温差,容易产生温度裂缝,影响桥梁的耐久性和安全性。本文以内蒙古宝贝河大桥预应力混凝土连续T型梁桥为研究对象,对试验梁的温度数据进行了观测,获得了大量的实测温度数据。以试验梁实测温度数据为依据,分别对混凝土水化热作用与日照温度作用下的试验梁温度分布模式进行了分析。研究了截面尺寸、砼入模温度对水化热温度分布的影响。以传热学理论为基础,使用大型有限元软件ABAQUS模拟混凝土T型梁在水化热阶段的热量变化过程。采用《大体积混凝土温度应力与温度控制》一书中给出的复合指数式,计算混凝土水化放热量。通过模型计算值与现场实际测量的温度值进行对比,得出了适用于计算混凝土T型梁水化放热量的参数a、b。运用修正后的有限元模型,分析了混凝土T型梁水化热温度场的分布情况。
[Abstract]:With the sustained and steady growth of China's national economy, the transportation industry is booming, the number of bridges needed to be built is huge, and the industry of bridge construction is booming.Among the many bridge types, prestressed concrete T-beam bridge is often chosen as the best bridge type with its outstanding advantages such as large stiffness, strong torsional resistance, good integrity and smooth running.However, in recent years, many prestressed concrete continuous T-beam bridges at home and abroad have different degree of cracks in the process of use.This phenomenon has attracted the attention of bridge experts and researchers both at home and abroad. These scholars have proved that the main cause of cracks in bridge structure is temperature stress.The thermal conductivity of concrete is poor. Under the effect of temperature, the temperature difference of bridge structure is large, and the temperature crack is easy to occur, which affects the durability and safety of the bridge.This paper takes Prestressed concrete continuous T-beam bridge of Baohe Bridge in Inner Mongolia as the research object. The temperature data of the test beam are observed and a large number of measured temperature data are obtained.Based on the measured temperature data of the test beam, the temperature distribution model of the test beam under the action of hydration heat of concrete and sunshine temperature is analyzed respectively.The effect of cross section size and concrete injection temperature on the temperature distribution of hydration heat is studied.Based on the theory of heat transfer, a large-scale finite element software ABAQUS is used to simulate the heat change process of concrete T-beam in hydration heat stage.The heat release of concrete hydration is calculated by using the compound exponential formula given in the book "temperature stress and temperature Control of Mass concrete".Based on the comparison between the calculated values of the model and the temperature values measured in the field, the parameters a / b suitable for the calculation of the hydration heat release of concrete T-beams are obtained.Based on the modified finite element model, the distribution of temperature field of concrete T-beam hydration is analyzed.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.5

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