Abstract
The area of desolated field caused by an excess spring water is increasing, especially in the low lying paddy field at valley bottom. In this paper, the authors reported the method for controlling spring water by mean of horizontal interceptive layer. This method enables one to capture the spring water with interceptive layer and guides the intercepted water to underdrains. The dynamic characteristics of spring water in several conditions were analyzed by finite element method, and reliability of calculated results were confirmed with sand model examination.
The results obtained are summarized as follows;
1) The separately installation of underdrains and interceptive layer produces higher drainage effect in comparison with closely installation.
2) When the spacing between underdrains and interceptive layer attains to a specified length, mean groundwater level becomes minimum and water table shows flat.
3) In case the interceptive layer has less permeability than a critical value (Kc), drain capability of that method is a almost equal to impermeable layer method. When interceptive ratio (Ls) is estimated at 25%, Kc is about 1% of coefficient of saturated water conductivity.
