城市预应力混凝土曲线梁桥温度场及温度效应研究

发布时间：2018-03-24 17:59

本文选题：曲线梁桥　切入点：城市　出处：《南京工业大学》2015年硕士论文

【摘要】：随着我国城市化进程的不断推进,混凝土曲线梁桥在城市高架和大型互通立交中的应用越来越广泛。但混凝土曲线梁桥在使用过程中不断发现的“典型病害”问题值得关注,而温度作用是曲线梁桥产生典型病害的原因之一,而现行城市桥梁设计规范中的温度场规定是参照公路规范制定的。为了研究清楚城市混凝土曲线梁桥在温度场及温度对典型病害的贡献情况,本文针对一座2×5m的预应力混凝土曲线箱梁模型桥进行了长达两年的温度观测和端支承反力观测,以实测数据为基础,通过仿真分析拟合了适合城市地区的温度场模型,然后对混凝土曲线梁桥的温度作用效应开展了系列的分析和研究。主要工作有以下几个方面：(1)以一座2×5m的预应力混凝土曲线箱梁模型桥为依托,设计制定了长期温度观测和支反力观测试验方案。并对观测的数据按春、夏、秋、冬进行分析,通过分析得出一年中最不利的温度场。(2)基于桥梁在大气中的热交换过程的分析,总结箱梁温度场边界热力参数计算方法,以此为基础用ABAQUS程序对该桥温度场进行了仿真模拟,仿真结果与实测数据吻合较好,从而验证了本文模拟温度场方法的正确性。(3)基于温度场的实测数据,确定了试验桥的升温温度梯度模式和降温温度梯度模式,并与现行规范中的温度梯度模式进行了对比分析。最后,对该桥的温梯度效应进行了数值分析,实测支反力与计算支反力吻合较好从而验证了本文有限元计算模型的可靠性。(4)根据实测地区的环境条件,分别研究了年温差及实测城市日照温差作用下,试验模型桥的曲线梁桥的应力、位移、支座反力等变化规律,并分析温度对曲线梁桥产生“典型病害”的关系。分析结果表明；年温差作用下曲线梁桥会产生纵向的爬移现象；温度梯度会使曲线梁桥发生明显的径向偏移或翻转,且在墩梁固结处产生的拉应力,易产生裂缝。(5)根据实测城市地区温度场与公路规范中规定的温度场进行温度效应的比较分析,并研究了城市温度梯度下,曲率半径与支座布置形式对曲线梁桥温度效应的影响,结果表明：城市温度场下的温度效应较公路规范下的温度效应偏安全；改变曲率半径,曲率半径越大,径向位移越小,且支座反力差越小,曲线梁桥受力越均匀。通过改变支撑布置形式计算可得,一般情况下小半径曲线梁桥采用抗扭支撑与点铰支撑交替布置的形式。改变端部抗扭支撑间距,在正、负温度梯度下,减小了内外侧反力差,使梁内外侧受力趋于均匀。
[Abstract]:With the development of urbanization in China, concrete curved girder bridges have been widely used in urban viaducts and large interchanges. However, the problems of "typical diseases" found in the use of concrete curved girder bridges are worthy of attention. And temperature is one of the causes of typical diseases of curved girder bridges. In order to study the contribution of temperature field and temperature to typical diseases of urban concrete curved girder bridge, the temperature field of the current urban bridge design code is formulated with reference to the highway code. In this paper, a 2 脳 5m prestressed concrete curved box girder model bridge is used for two years of temperature observation and end support reaction observation. Based on the measured data, the temperature field model suitable for urban area is fitted by simulation analysis. Then a series of analysis and research on the effect of temperature on concrete curved girder bridge are carried out. The main work is as follows: 1) based on a 2 脳 5m prestressed concrete curved box girder model bridge. The long-term temperature observation and reaction force observation test scheme is designed and established. The data of observation are analyzed according to spring, summer, autumn and winter. Through the analysis, the most unfavorable temperature field in the year is obtained, which is based on the analysis of the heat exchange process of the bridge in the atmosphere. The calculation method of the boundary thermodynamic parameters of the box girder temperature field is summarized. Based on this method, the temperature field of the bridge is simulated by ABAQUS program. The simulation results are in good agreement with the measured data. Therefore, the correctness of the method of simulating the temperature field in this paper is verified. (3) based on the measured data of the temperature field, the temperature gradient model and the temperature gradient model of the test bridge are determined. Finally, the temperature gradient effect of the bridge is numerically analyzed. The reliability of the finite element calculation model of this paper is verified. (4) according to the environmental conditions of the measured area, the annual temperature difference and the measured urban sunshine temperature difference are studied respectively. The stress, displacement and bearing reaction force of the curved girder bridge of the test model bridge are changed, and the relationship between temperature and the "typical disease" of the curved girder bridge is analyzed. The results show that the longitudinal climbing phenomenon of the curved beam bridge will occur under the action of annual temperature difference; The temperature gradient will cause obvious radial deviation or reversal of curved beam bridge and the tensile stress in the consolidation of pier beam. According to the temperature field measured in urban area and the temperature field specified in highway code, the effects of curvature radius and support arrangement on the temperature effect of curved girder bridge are studied under the urban temperature gradient. The results show that the temperature effect under the urban temperature field is more secure than that under the highway specification, the larger the radius of curvature, the smaller the radial displacement and the smaller the difference of support reaction force. The more uniform the force is, the more uniform the force is. It can be obtained by changing the form of support arrangement. In general, the small radius curved girder bridge is arranged alternately between torsional bracing and point hinge bracing. The distance between end torsional bracing and negative temperature gradient is changed. The difference of reaction force between inside and outside side is reduced, and the force inside and outside the beam tends to be uniform.
【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.5

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