Safety Analyzing Of Dams Of The Upper And Lower Reservoirs At Tongbai Pumped Storage Power Station

Based on safety monitoring projects of Tongbai Pumped Storage Power Station, the field monitoring and numerical simulation of the homogeneous earth dam and concrete face rock-fill dam at the upper and lower reservoirs were done in this article. The deformation and seepage of the dams at the upper and lower reservoirs were analyzed.The main conclusions are as follows.The monitoring data analysis of earth dam shows that settlement of homogeneous earth dam increased with an increase in height of dam section. When the upper reservoir rises, the horizontal displacement oriented to downstream and increased with the water level rise.The simulation analysis of earth dam seepage and stability shows that short-term cyclical changes of water level only rises to saturation line in local area at the upper side of dam, and saturation line in the rest dam body remains unchanged. When quickly lowering the water level, seepage to the upper foot of the dam will come up. This causes a negative impact on the upper side stability of dam. The numerical analysis indicates that stability factor of homogeneous earth dam is greater than 1.3.The monitoring data analysis of concrete face rock-fill dam shows that settlement of concrete face rock-fill dam increased with an increase in filling height of dam and water storage level. Most of settlement of the dam has been completed during construction. After reservoir filling, the more is close to the upstream side, the new settlement account for the greater proportion of the total settlement. After dam base grouting, the exudation pressures of fault and mudstone strip rapidly decay with an increasing of the distance from the upside, which indicated that dam base has a good impermeability.The deformation of vertical joints of concrete face rock-fill dam was affected by atmospheric temperature and water level. The deformation of vertical joints inverses with temperature variation, and agrees thermal expansion and shrinkage theory. Water level rising causes the width of vertical joints under water level to decrease. The deformation of vertical joints located at middle portion of the dam is compression, while vertical joints located at shoulder of the dam is opening.