太阳辐射条件下冰温度膨胀力对某水库放水塔工作桥柱裂缝的影响

寒冷地区冬季水工建筑物受冰温度膨胀力破坏严重,为研究不同方位角处太阳辐射量对混凝土柱裂缝开展的影响规律,结合某水库放水塔工作桥裂缝实测结果,采用冰热力耦合理论及扩展有限元方法模拟了混凝土柱12h冰盖升温膨胀对工作桥混凝土柱的挤压破坏过程。结果表明,模拟裂缝开展深度与现场实测结果基本吻合;阳面(方位角为30°)冰盖瞬时吸收的太阳辐射量最大值为阴面(160°)的1.3倍;由于太阳辐射,冰盖上表面逐小时温度变化值增大为未加入前的1.8倍;温度变化较大与阴面冰盖吸收的太阳辐射较少有关,阴面冰盖升温膨胀挤压混凝土柱产生的裂缝深度值为阳面的3倍。研究成果可为寒冷地区抗冰冻设计提供借鉴。

Study on Influence of Ice Temperature Expansion Force on Cracks in Working Bridge Columns under Condition of Solar Radiation

Winter hydraulic structures in severe cold regions are severely damaged by ice temperature expansion. In order to study the impact of solar radiation on concrete column cracks at different azimuth angles, combined with the crack observation data of working bridge for drain tower of a certain reservoir, the ice-thermal coupling theory and extended finite element method were used to simulate the concrete column 12 h ice sheet heating and expansion to concrete. The results show that the depth of simulated cracks is in good agreement with the field test values. The maximum amount of solar radiation absorbed by the ice cover (the azimuth angle is 30°) is 1.3 times of the gray surface (160°); The hourly temperature change of the upper surface of the ice sheet increases. The change value is 1.8 times that of the solar radiation before the addition of solar radiation. Since the solar radiation absorbed by the cloudy ice cover is less, the temperature changes greatly, and the crack depth of the extruded concrete column is 3 times that of the positive surface. The result can be used for reference to the anti-freezing design and engineering measures of hydraulic structures in the cold regions.