混凝土曲线箱梁桥的空间日照温度场

Spatial sunshine temperature field of concrete curved box girder bridge

为研究混凝土曲线箱梁桥的空间日照温度场及其变化规律,首先,基于传热学理论和太阳辐射三维遮挡理论,考虑混凝土封闭空间内部空气换热,提出了基于有限元法的曲线箱梁桥空间日照温度场计算流程;然后,以河北省某在建混凝土曲线箱梁桥为工程案例,分析了2019年夏至日桥梁空间日照温度场的时变规律,并研究了曲率半径和翼缘板宽度对混凝土曲线箱梁桥空间日照温度场的影响。研究结果表明:由于曲线箱梁桥翼缘板的遮挡效应和太阳东升西落入射角的变化,不同截面腹板的温度时变规律有差异,西侧腹板比东侧腹板截面最高温出现的时间滞后约3 h;曲线箱梁桥外侧腹板的正向竖向温度梯度温差最大,约为15.3℃,不同截面外侧腹板温差最大约0.8℃;翼缘板宽度对混凝土曲线箱梁桥的空间温度分布特征影响较为明显,而曲率半径对其影响较小。

In order to study the spatial sunshine temperature field and its variation law of concrete curved box girder bridge,firstly,based on the theory of heat transfer and the three-dimensional shielding theory of solar radiation,the air heat transfer in concrete enclosed space was considered,the calculation process of spatial sunshine temperature field of curved box girder bridge based on finite element method was proposed.Then,a concrete curved box girder bridge under construction in Hebei Province was chose as an engineering case,the time-varying law of the spatial sunshine temperature field of the bridge on the summer solstice of 2019 was analyzed,and the influence of curvature radius and flange width on the spatial sunshine temperature field of the concrete curved box girder bridge was analyzed.The results show that due to the shielding effect of the flange plate of the curved box girder bridge and the change of the incident angle of the sun rising in the east and setting in the west,the temperature time-varying law of the webs of different sections is different.The time of the highest temperature of the west web section is about 3 hours later than that of the east web section.The positive vertical temperature gradient temperature difference of the outer web of the curved box girder bridge is the largest,about 15.3℃,and the maximum temperature difference of the outer web of different sections is about 0.8℃.The width of flange plate has obvious influence on the spatial temperature distribution characteristics of concrete curved box girder bridge,while the radius of curvature has little influence on it.2 tabs,18 figs,25 refs.