Numerical investigation of capillary barrier performance with transport layer

Abstract

A capillary barrier is a promising alternative measure for controlling rainfall infiltration in unsaturated residual soil slopes. Although, capillary barriers have been successfully applied to avert rainfall infiltration in dry and semi-dry climates, its application in humid climates with high precipitation rate is still unsatisfactory. Therefore, this paper evaluates the performance of modified capillary barrier with transport layer under humid climates. The capillary barrier was simulated with Grade V and Grade VI soil and the transport layer was made with gravel material. The complete slope model was subjected to a 24-hour rainfall intensity of 14.6 mm/hr using saturated/unsaturated seepage analysis software (Seep/W). The results show that the diversion length and breakthrough time were greatly improved in the modified capillary barrier with transport layer than the conventional capillary barrier system. Therefore, the inclusion of transport layer in a residual soil capillary barrier improved its performance.