Causes of Ponding in Foundation Gallery of Fenhe Reservoir II Gravity Dam

The multi field coupling mechanism of seepage, stress and temperature coupling of concrete gravity dam is analyzed, and its coupling control equation is deduced. Based on the analysis of the temperature effect of cracked concrete dam, a three field coupling model of seepage, stress and temperature based on pore crack dual medium suitable for the characteristics of RCC gravity dam is established, and its implementation strategy in COMSOL Multiphysics is studied. The three-dimensional finite element model of the overflow dam of Fenhe Reservoir II is established, and the annual working behavior of the overflow dam section is simulated in COMSOL Multiphysics. The variation law of dam seepage characteristics under the coupling action of seepage, stress and temperature is obtained. It is considered that the ponding in the gallery mainly comes from the crack leakage, and the temperature and headwater elevation are the main factors affecting the crack leakage of the dam.