Abstract |
The report discusses and evaluates different approaches to solving transient groundwater-flow problems associated with the two-dimensional drainage of a phreatic aquifer in a homogeneous isotropic soil, presents a new method to describe the transient flow under these conditions, and describes the experimental techniques used to evaluate the analytic solutions. Exact analytical treatment of the problem of groundwater flow toward tile drains or trenches is difficult because of the complicated non-linear boundary condition on the free surface. Based on the conformal mapping technique proposed by Kalinin, the cases of a single drain, two parallel drains, and periodic drains were considered under the assumption of a semi-infinite solution domain. The results indicate that solutions based on the Dupuit-Forcheimer assumption produce highly unrealistic results, even for use as rough approximations. The applicability of the analytic technique is limited to relatively small values of the time parameter, T less than 1.5, and to semi-infinite seepage domain. (Author) |