Construction and Test of an Instrumented 2D Channel with Rainfall and Insolation Control

Abstract

This paper presents the construction and testing of a large instrumented 2D channel for the simulation of the performance of compacted barriers under controlled conditions of insolation and rainfall. Details of the main apparatus devices and capabilities and the results of a long-term test performed on a capillary barrier (CB) are presented. The performed test aimed to simulate the behavior of the CB over 1 year in typical semi-arid conditions. The channel behavior was considered very promising. Boundary conditions in terms of rainfall and insolation were adequately properly imposed and suction values, moisture content, runoff and bottom drainage were measured throughout the test. As for the CB performance, the upper clayey layer of soil presented undesirable shrinkage cracks that impacted the CB performance, mainly at the end of the period of evaluation. The obtained results point to the need to use of thicker layers than used in the experiments in order to preserve the integrity of the clayey soil near the interface with the bottom coarse soil layer.