EVALUATION OF WATER DYNAMICS IN UNSATURATED SOIL HORIZONS IN BAIXADA SANTISTA-SP

• Grant number: 24/10325-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2024
• End date: August 31, 2025
• Field of knowledge: Engineering - Civil Engineering - Geotechnical Engineering
• Principal Investigator: Mariana Ferreira Benessiuti Motta
• Grantee: Leonardo Henrique Pinto Nogueira
• Host Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil

Abstract

Landslides are natural phenomena, but human action can facilitate and accelerate this process. During heavy rains, common in Brazil, the situation becomes worrying and there is a greater probability of such disasters occurring, since the soil is in its most critical situation, with a high degree of saturation. Therefore, understanding the behavior of water in a given soil is essential for carrying out effective risk monitoring. In this scope, this research project is proposed, linked to the FAPESP research already approved under process number 2023/04461-4, aiming to simulate different precipitation scenarios in unsaturated soil profiles monitored by CEMADEN (National Center for Monitoring and Alerts for Natural Disasters) with moisture sensors, through geotechnical data collection platforms (PCDs), in Baixada Santista-SP. The main objective is to determine moisture ranges associated with risks, thus ensuring greater refinement in alert emissions for the location. To this end, based on the characterization of two sites already studied in the main project and the other two researches linked to it, and data obtained from monitoring the profiles, models will be performed with the aid of GeoStudio software to study scenarios and understand the main processes associated with soil behavior in these sites. The models will be divided into two parts, considering the analysis of transient flow in unsaturated soils and stability analyses coupled with flow analyses. The safety factors (SF) will be obtained considering the method proposed by Morgenstern-Price, for circular and non-circular rupture surfaces. Considering similar conditions found in other landslide cases already reported in the literature, the importance of numerical modeling integrated with the moisture monitoring system is highlighted. This study may serve as a reference in decision-making for improving warning systems linked to mass movements.