预应力混凝土连续道岔梁桥温度效应分析

Analysis of the Temperature Effects on the Pre-Stressed Concrete Bridge with a Continuous Turnout Beam

某在建十三跨预应力混凝土连续箱梁桥由于连续跨数多、超静定次数高、受温度影响显著,采用Midas/Civil软件对其梁体在温度梯度作用下应力分布进行分析,同时采用美国AASHTO规范中的分地区温度标准值进行对比分析。结果表明:截面的最大拉应力出现在箱梁顶板的底面位置且数值已远大于混凝土抗拉强度,设计中应采取措施预防裂缝的产生;大跨度高次超静定混凝土箱梁桥的温度敏感性更高,不同温度标准值下,桥梁温度应力差异明显;建议对温度标准值的取值采取按地区温度差异来选取,但可行性还待进一步检验。

Since the number of the spans of the thirteen-span pre-stressed concrete continuous box girder bridge under construction is great, the number of times of statical indetermination is high, and the bridge is significantly affected changes in temperature, the stress distribution caused by the temperature gradient is analyzed with the software of Midas/Civil, with the standard values for the temperature in various districts prescribed in the American AASHTO specifications used to compare with and analyze the calculated results. The results show that the maximum tensile stress appears at the bottom of the top plate of the box girder,and the value is far greater than the tensile strength of the concrete, in which case some measures have to be taken to prevent cracks during the design; the temperature sensitivity of the highly indeterminate large-span concrete bridge is higher, and under the action of different standard temperature values,the difference in bridge temperature stress is significantly obvious; As a result, the temperature standard values ） should be taken according to the difference in temperature of different districts. Even so, the feasibility still needs further testing.