高海拔地区日照对箱式渡槽热力效应分布研究

Impacts of sunshine on thermal distribution of box aqueduct in high altitude areas

为研究高海拔地区日照对箱式渡槽的热力效应分布特征,为箱式渡槽结构的设计和施工提供指导,根据热传导理论及水工渡槽的温度边界条件对某高海拔地区箱式渡槽利用ANSYS进行了日照辐射的热力分布仿真分析,得出其各壁板总体温度呈外高内低的二次曲线分布状态,壁板温度应力表现为外表面受压内表面受拉的分布状态,横向与竖向最大温度拉应力分别出现于顶板内侧与腹板内侧,最大温度压应力出现于顶板与腹板外侧,各壁板内外表面的温度应力呈先增后减趋势。因此,在进行箱式渡槽结构的设计和施工中通过配置温度钢筋、施加横向预应力或增加表面隔热措施来改善渡槽在日照作用下的热力分布状态,保证结构安全运行。

The impacts of sunshine on thermal distribution of box-type aqueducts in high-altitude areas provide guidance for the design and construction of box-type aqueduct structures.The ANSYS is used in this study for a high-altitude box-type aqueduct,based on the heat conduction theory and the temperature boundary conditions of hydraulic aqueducts.The simulations of thermal distributions of the solar radiation show that the temperature of each wall is higher outside and lower inside with a quadratic distribution.The temperature stress of the wall is under expansion for the inner surface and under compression for the outer surface.The vertical maximum tensile stress appears on the inside of the top plate and the inside of the web.The maximum temperature compressive stress appears on the outside of the top plate and the web.The temperature stress on both inner and outer surfaces of each wall increases firstly and then decreases.Therefore,installation of temperature steel bars,lateral prestressing or surface heat insulation measures should be provided to improve the stress state of the aqueduct under the action of sunlight,and to make sure the safe operation of the structure,in the design and construction of the box aqueduct structure.