Deformation analysis of an unsaturated geosynthetic reinforced soil wall subjected to infiltration

Abstract

Geosynthetic-reinforced soil walls are structures typically constructed with compacted and thus unsaturated soils. The use of local fine-grained soils as backfill material has been a common practice in view of the significant cost reduction in comparison to granular backfills. This is especially applicable in tropical areas where lateritic soils are found as these material scan exhibit outstanding geotechnical properties mainly under unsaturated conditions. Thus, it is possible to optimize the design and construction of geosynthetic-reinforced soil walls considering soil unsaturation, however it is not known to what extent infiltration can reduce soil suction impairing the safety of the structure. To address the influence of suction on the behavior of geosynthetic structures, a full-scale geotextile-reinforced wall was subjected to infiltration and instrumented to capture the distribution of moisture and soil suction along the reinforced zone, as well as reinforcements strains. This paper presents and discuss the influence of geotextile reinforcement acting as capillary barrier coupled with the wall performance. Results demonstrate that the advancement of infiltration front has a more pronounced effect on deformation as the changes on water contents. Capillary barriers were found to occur retarding infiltration, but not affecting the overall performance of the structure. The average of monitored suction values along the wall height, herein called as “global suction”, was found to be strictly related to maximum reinforcement strains behavior.