The behaviour of capillary barrier covers (CBCs) subjected to rainfall has been extensively studied by many researchers. However, the patterns of rainfall are seldom considered in previous studies, and therefore, the behaviour of CBCs subjected to rainfall with different patterns is still unknown. To this end, this study aims to investigate the effect of rainfall patterns on the behaviour and performance of CBCs, and identify the rainfall pattern, under which the performance of the CBC is the worst. Using a newly developed soil column test apparatus, a series of laboratory soil column experiments were conducted. The results indicated that when rainfall duration is short, the patterns of rainfall only affect the volume water content (VWC) and pore water pressure (PWP) significantly at the upper part of the column; when rainfall duration is long, the patterns of rainfall can significantly affect the VWC and PWP throughout the whole column. The percolation and breakthrough time of the CBC were also influenced by rainfall patterns; the advanced rainfall pattern produced the largest percolation, and resulted in the shortest time for CBCs to break through, whereas the delayed rainfall pattern generated the least percolation and resulted in the longest time for CBCs to break through. Based on the percolation and breakthrough time, it seems that the advanced pattern is the worst-case scenario for the CBCs subjected to rainfall. The obtained results not only imply the necessity of rainfall patterns to be involved in the study of the CBCs subjected to rainfall but they also can be helpful for the practical design of the CBCs.
This is an open access article distributed under the Creative Commons Attribution License
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited