温度变化对水电站蜗壳结构配筋的影响

水电站厂房下部结构是一个多孔洞的大体积混凝土结构，受力状况复杂，尤其是在温度变化作用下，蜗壳周边混凝土的应力状态更是难以确定，为此，运用三维有限元对某水电站地下厂房下部结构进行了数值分析，确定其在运行期间的最高温升、最大温降、半数磁极短路以及蜗壳未充水最大温降4种工况下的应力分布状态．根据数值计算的结果得到平行机组安装高程6个平面的环向应力和8个典型纵剖面的环向应力，然后进行配筋计算，分析温度变化对水电站厂房下部结构配筋的影响，为今后分析水电站厂房下部结构的温度应力以及优化水电站蜗壳外围混凝土的配筋提供了可靠依据。

Influence of Changing Temperature on Reinforcing Bars of Spiral Casing Structure in a Hydropower Station

The powerhouse has an underside structure of mass concrete with many holes.Its stress is complex. The stress of the surrounding concrete around the spiral case is especially difficult to be ascertained,when the underside structure is affected by changing temperature.The underside structure of an underground powerhouse in a hydropower station was analyzed using 3-D finite element method (FEM),and the stress distribution was determined under four conditions,including maximum temperature rising,maximum temperature falling,half of the magnetic pole shorting during the runtime,and maximum temperature falling with the spiral case no water. The circumferential stresses of six cross sections parallel to the altitude where the water turbine is fixed and eight typical longitudinal sections were obtained according to the numerical analysis results.Then the reinfor- cing bars were calculated and the influence of the changing temperature on the reinforcing bars of the underside structure of the powerhouse was analyzed,the result of which provides a reliable basis for the temperature stress analysis of the underside structure of the powerhouse and the optimization of the reinforcement of the surround- ing concrete around the spiral case.