The seepage under a dam foundation is mainly controlled by the performance of the curtain.Its anti-seepage behavior may be weakened by the long term physic-chemical actions from groundwater.According to seepage hydraulics and geochemistry theory,a coupling model for assessing the behavior of the curtain under a dam foundation is set up,which consists of seepage module,solute transport module,geochemistry module and curtain erosion module,solved by FEM.A case study was carried out.The result shows that the curtain efficiency is weakened all the time.Aqueous calcium from the curtain is always in dissolution during the stress period for simulation,which leads to the increasing amount in groundwater reaching 846.35-865.312 g/m3.Within the domain,reaction extent differs in different parts of the curtain.The dissolution of Ca(OH)2 accounts to 877.884 g/m3 near the bottom and is much higher than that of the other parts.The erosion is much more serious near the bottom of the curtain than the other parts,which is the same to the upstream and downstream.Calcium dissolution is mainly controlled by hydraulic condition and dispersion,and it varies in a non-linear way within the domain.
The seepage under a dam foundation is mainly controlled by the performance of the curtain. Its anti-seepage behavior may be weakened by the long term physic-chemical actions from groundwater. According to seepage hydraulics and geochemistry theory, a coupling model for assessing the behavior of the curtain under a dam foundation is set up, which consists of seepage module, solute transport module, geochemistry module and curtain erosion module, solved by FEM. A case study was carried out. The result shows that the curtain efficiency is weakened all the time. Aqueous calcium from the curtain is always in dissolution during the stress period for simulation, which leads to the increasing amount in groundwater reaching 846.35-865.312 g/m^3. Within the domain, reaction extent differs in different parts of the curtain. The dissolution of Ca(OH)2 accounts to 877.884 g/m^3 near the bottom and is much higher than that of the other parts. The erosion is much more serious near the bottom of the curtain than the other parts, which is the same to the upstream and downstream. Calcium dissolution is mainly controlled by hydraulic condition and dispersion, and it varies in a non-linear way within the domain.