Numerical simulation of a geotextile soil wall considering soil-atmosphere interaction

This paper presents a numerical method for considering soil-atmosphere interaction applied to infiltration into an unsaturated geosynthetic reinforced soil wall and its effect on wall stability. A hypothetical nonwoven geotextile reinforced soil wall was subjected to simulated conditions of evaporation and precipitation over 2 years considering local climate variation in São Paulo city, Brazil. Net infiltration and actual evaporation were quantified inside and outside the reinforced zone, allowing for the assessment of changes in soil suction and factors of safety. The study discusses the implications of using in-plane draining reinforcements (e.g. nonwoven geotextiles) and soil-atmosphere effects. Results show that soil suction and factors of safety variation are more dependent on consecutive days of precipitation than on isolated heavy rainfalls. For the climate conditions considered in this study, results show that approximately 50% of the precipitation and potential evaporation transformed into net infiltration and actual evaporation, respectively. Additionally, the numerical results indicate that after the first wetting of the soil inside the reinforced soil zone, the evaporation to the atmosphere did not remove water from the inside of the geosynthetic reinforced wall because of the capillary break.