Banca de DEFESA: Patrícia Figuereido de Sousa

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Patrícia Figuereido de Sousa
DATE: 20/08/2024
TIME: 14:00
LOCAL: Sala Teams (On-line)
TITLE:

A Constitutive Model for Predicting Unsaturated Shear Strength Using the Soil-Water Retention Curve of Unimodal and Multimodal Soils.

KEY WORDS:

Unsaturated Soils. Multimodal Soils. Shear Strength. Soil-Water Retention Curve. Mohr-Coulomb Envelope.

PAGES: 187
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SUMMARY:

Proper characterization of the shear strength properties of unsaturated soils is essential for addressing various geotechnical problems, including the evaluation of foundation bearing capacity, the determination of the stability of natural slopes and dam embankments, and the design of retaining structures. Experimental determination of unsaturated shear strength is generally expensive, time-consuming, and challenging. However, since the shear strength of unsaturated soils is strongly related to the moisture content in the medium, as well as to suction and the material's retention properties, it is possible to infer that the shear strength of an unsaturated soil can be estimated from the Soil-Water Retention Curve. Thus, within this research framework, this study proposes new models for predicting the shear strength of unimodal and multimodal unsaturated soils. The proposed predictive models are based on the modified Mohr-Coulomb failure envelope for unsaturated soils, the soil-water retention function, and the parameters of effective shear strength, cohesion, and friction angle. Based on this, new models of unsaturated shear strength surfaces and unsaturated cohesion are also defined. Some applications of these models are presented, showing good fit and representation in relation to experimental data from the literature. This study also evaluates the influence of the void ratio on the retention and strength of unsaturated soils. Additionally, a constitutive hydraulic model for multimodal soils is developed and presented. The main results of the research allow us to relate the physical, mechanical, and hydraulic behavior of soils based on the modality they present, highlighting a possible practical application that is subject to further validation as more complex phenomena such as collapse, expansion, and hysteresis were not considered in this study. Despite this, through the mathematical functions and examples presented, the research can contribute to disseminating and popularizing concepts of unsaturated soil mechanics, allowing retention models to predict the strength behavior of soils in an unsaturated state.

COMMITTEE MEMBERS:
Presidente - 1805002 - ANDRE LUIS BRASIL CAVALCANTE
Interno - 404827 - ANDRE PACHECO DE ASSIS
Interno - 2161425 - JUAN FELIX RODRIGUEZ REBOLLEDO
Externo à Instituição - MARCOS MASSAO FUTAI - USP
Externo à Instituição - ORENCIO MONJE VILAR - USP