Banca de DEFESA: Jair Ochoa Valderrama

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Jair Ochoa Valderrama
DATE: 04/10/2023
TIME: 09:00
LOCAL: Sala de Interação - CDT
TITLE:

Simulation of rock behavior at laboratory scale using the heterogeneous CVBM

"Simulation of rock behavior at laboratory scale using the heterogeneous CVBM"

KEY WORDS:

Internal Heterogeneity of Rock, Continuum Voronoi Block Model, Numerical Simulation, Characteristic Stresses

PAGES: 133
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SPECIALTY: Mecânicas das Rochas
SUMMARY:

With the increasing demand for underground construction projects, there has been a growing need to understand and predict the behavior of rocks when subjected to different types of external loads. Multiple experimental and numerical techniques have been developed to represent the various phenomena involving rocks and rock masses. One of these techniques is the Continuum Voronoi Block Model (CVBM), which, with its pseudo-discontinuous approach, has proven to be a numerical tool capable of simulating rock behavior on both field and laboratory scales, assuming a single material for the entire set of blocks and joints used in its representation. However, in recent years, the contribution of other sources of heterogeneity for a more accurate modeling of rocks has been recognized, allowing for more realistic failure modes and a development of macroscopic stresses closer to laboratory results, especially in cases of confined compression. For these reasons, in this work, material and contact heterogeneity were integrated into the CVBM using a script developed in the Python language. As a case study, the behavior of Äspö diorite was represented when subjected to different types of laboratory tests (simple and confined compression, indirect tension, cyclic loading, and fracture toughness), analyzing the impact of different parameters, the size of constituent elements, and spatial and structural variability on elastic response, characteristic stresses, and model strengths. The heterogeneous CVBM adequately simulated the rock's macroscopic response, capturing the natural variability of the results and the development of different types of fractures throughout the loading process. The new features added to the model resulted in early development of tensile stresses within the material, causing the gradual growth of fractures, impacting characteristic stresses and the extent of the unstable fracture growth zone. Additionally, other types of rocks with specific internal structural characteristics (foliation planes or inclusions) were represented, culminating in the extension of the procedure to the application of the probabilistic approach for defining properties within the test body.

COMMITTEE MEMBERS:
Presidente - 404827 - ANDRE PACHECO DE ASSIS
Interno - 1549489 - MANOEL PORFIRIO CORDAO NETO
Interno - 404227 - MARCIO MUNIZ DE FARIAS
Externo à Instituição - CARLOS ALBERTO LAURO VARGAS - UFG
Externo à Instituição - PEDRO PAZZOTO CACCIARI - EPM