热沥青混合料桥面铺装对箱型桥梁温度效应的影响

发布时间：2018-05-04 10:45

本文选题：室内 + 钢筋混凝土箱梁　；参考：《苏州科技学院》2015年硕士论文

【摘要】：虽然混凝土箱梁桥面热沥青混合料摊铺过程在整个施工期间较短,但是在此过程中桥梁产生了比较大的应变与应力,会造成箱梁桥,特别是连续箱梁桥产生顶板、腹板、底板及翼缘等多处开裂。本课题组在室内按1:2预制了长2m,宽1.2m的标准混凝土简支箱梁模型,并在箱梁内部共埋设117个混凝土及钢筋应变片,120个温度传感器。在箱梁顶板摊铺4cm厚155℃SMA沥青混合料,对摊铺后箱梁顶板、翼缘、腹板及底板处温度及应变进行采集。观测混凝土箱型在高温沥青摊铺状态下其温度场及温度应力、应变的分布规律,探究在危险时刻本混凝土箱梁的温度梯度及应力、应变沿箱梁截面分布规律。本研究通过试验室模拟试验研究混凝土简支箱梁结构在沥青高温摊铺状态下箱梁内部温度场及温度效应分布情况,得到了以下主要结论:(1)该试验箱梁在本次沥青高温摊铺试验时最不利时刻沿箱梁腹板高度方向温度分布曲线大致呈双曲线分布规律,其中顶板处温度值T1取38℃,转折点出现在距顶板上缘16cm处,底板处温度值取0℃;(2)本试验箱梁最不利时刻出现在高温沥青混合料摊铺后45min,此时应变沿截面高度方向呈曲线分布,拉应变最大值为-127.6uε,出现在距顶板16cm处,顶板位置主要为压应变,最大压应变达240uε,腹板主要表现为拉应变,底板处主要表现为压应变;(3)箱梁应力分布规律与(2)中应变分布规律相似,与之对应的最大拉应力为-2.80MPa,最大压应力为5.27MPa。
[Abstract]:Although the paving process of the hot asphalt mixture of concrete box girder bridge is shorter during the whole construction period, the bridge produces a lot of strain and stress in this process, which will cause the cracking of the roof, web, floor and flange of the box girder bridge, especially the continuous box girder bridge. The subject group prefabricated a long 2M and wide 1.2m standard in the 1:2. In the box girder, 117 concrete and steel strain gauges and 120 temperature sensors are embedded in the box beam, and the temperature and strain of the top plate, flange, web and bottom of the box girder are collected at the top of the box beam, and the concrete box type in the high temperature asphalt paving state is observed. The temperature field, the temperature stress and the distribution of the strain, explore the temperature gradient and stress and the distribution of the strain along the section of the box girder at the dangerous time. This study has studied the distribution of temperature and temperature effects in the box girder of concrete simply supported box girder structure under the high temperature spread of asphalt. The following main conclusions are as follows: (1) the temperature distribution curve of the test box beam along the height direction of the box girder web is approximately hyperbolic distribution curve at the most unfavorable time of the asphalt high temperature spreading test, of which the temperature value of the roof is T1 38, the turning point appears at the top edge of the top plate 16cm, the temperature of the bottom plate is 0 degrees C; (2) the worst case of the test box girder is the worst. The moment appears at 45min after the high temperature asphalt mixture spread. At this time the strain is distributed along the height of the cross section, the maximum tensile strain is -127.6u e, which appears at the top of the top plate 16cm. The top plate position is mainly pressure strain, the maximum pressure strain reaches 240u e, the web is mainly tensile strain, and the floor is mainly compressive strain; (3) the stress distribution gauge of the box girder. The law of strain distribution is similar to that in (2), and the maximum tensile stress is -2.80MPa, and the maximum compressive stress is 5.27MPa.

【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U443.33

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