中文摘要：

采用ANSYS有限元软件建立了山西中部引黄工程桥头渡槽混凝土T构3号块的有限元模型。在考虑昼夜气温变化的条件下,模拟了寒潮期间该渡槽早期的瞬态温度场和应力场。结果表明：该槽段截面侧墙的外表面和顶板与侧墙重叠处内外温差大,分别出现3.4 MPa和3.9 MPa的拉应力,需采取适当温控措施;计算节点的温度和温度应力都随昼夜气温变化而波动,且波动幅度和气温变化幅度成正比;在遭遇寒潮袭击、平均气温下降6℃的情况下,内外温差变大,该渡槽表面的应力提高0.5 MPa,这对于早龄期混凝土防裂是不利的。

英文摘要：

This paper used the ANSYS finite element software and established the finite element model of the 3rd block of the Qiaotou aqueduct that was an aqueduct in the Central Shanxi Yellow River Diversion Project. Under the conditions of considering the change of diurnal temperature,the temperature field and stress field of this aqueduct were truly simulated during cold wave. Some conclusions have been obtained through the calculation results. Sections of the aqueduct,the outer surface of the side walls,roof and side wall overlap appear 3.4 MPa and 3.9 MPa tensile stresses respectively because the concrete is thicker and the internal and external temperature difference is bigger. It is recommended taking appropriate measures to control temperature. The computed nodes′ temperature and the temperature stress change according to the change of diurnal temperature,and the amplitude is proportional to the change of air temperature. Under the conditions of the temperature dropping 6 ℃ during the cold snap,the temperature stress of the aqueduct will increase by 0.5 MPa,which is a disadvantage for early age concrete.