Three-dimensional numerical simulation for immersion prediction of left bank of Songyuan reservoir project

Aiming at the immersion problem caused by impoundment in plain area, taking the Songyuan reservoir project as an example, and on the base of generalizing the hydrogeologic structure of the left bank of Songyuan reservoir for a minding model, a three-dimensional transient flow numerical simulation model for predicting the immersion of the left bank of Songyuan reservoir project was built. The theory of three-dimensional finite difference numerical simulation was applied and the immersion area was obtained by simulation according to four impoundment schemes of non-diaphragm wall from the end of each month of April to October and with 4.05, 8.05 and 12.05 km diaphragm wall in the end of August. The results show that the total area of minimum immersion of non-diaphragm wall scheme is 127.62×104 m2 in April, and then gradually increases. It reaches the maximum with 1473.94×104 m2 in August, and then decreases. As the diaphragm walls are arranged along the left bank of reservoir in the unconfined aquifer, the immersion area decreases slightly.