气温骤降条件下混凝土面板温度应力及其保护措施研究

Research on the concrete face slab temperature stress and the protective measures under the condition of temperature sudden drop

结合某在建的混凝土面板堆石坝,针对施工期日温差及发生寒潮等气温骤降情况,进行了气温骤降条件下面板温度场及温度应力的全过程仿真分析。结果表明,在气温骤降条件下,面板表面及中心的温度将随气温骤降的发生而持续降低,其中面板表面温度降幅最大;此时面板表面和中心均出现拉应力,面板表面的最大主应力大于面板中心的最大主应力;面板表面和中心的最大主应力均发生在高程约为坝高一半的位置。采取保护措施,可以明显削减气温骤降所产生的面板降温幅度及最大主应力增幅,保护措施越强其削减效果越明显。

Combined with a concrete face rock-fill dam in process, the simulation analysis on the face slab＇s temperature field and temperature stress is processed in connection with the condition of temperature sudden drop caused by daytime temperature differences and cold wave and so on during the construction period. The result indicates that under the condition of temperature sudden drop, the temperature of face slab＇s surface and centre will fall consecutively along with the temperature sudden drop,and the face slab＇s surface temperature drop-out range will reach maximum;under this condition,the tensile stress appears in the face slab＇s surface and centre,the maximum principal stress in the face slab＇s surface is larger than that in the face slab＇s center;the maximum principal stress in the face slab＇s surface and centre both occurs in the position that the elevation equals approximately to half of the dam＇s height. Taking protective measures can obviously reduce the face slab＇s surface temperature drop-out range and the maximum principal stress amplification caused by temperature sudden drop, and the stronger protective measures are, the more obvious reduced effect is.