Banca de DEFESA: Sonny Albert Amorim da Silva

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Sonny Albert Amorim da Silva
DATE: 26/07/2023
TIME: 14:00
LOCAL: TEAMS
TITLE:

"Quantification of leaks through damages in geomembranes under different conditions"

KEY WORDS:

Geomembranes; Geosynthetics in Hydraulic Works; Damages in Geomembranes; Hydraulic Barriers

PAGES: 140
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SUMMARY:

Leakage through mechanical damages is a critical concern in geosynthetic systems, particularly with the use of PVC (polyvinyl chloride) and HDPE (high-density polyethylene) geomembranes. Mechanical damages can occur during installation, operation, or as a result of external factors causing punctures, cuts, or abrasions. This study aimed to evaluate water leakage through mechanical damages in smooth PVC and HDPE geomembranes with a thickness of 1 mm. Longitudinal cuts of 5 mm, 20 mm, and 50 mm were made using a blade, and holes of 2.2 mm and 5 mm were created to simulate damages in the geomembranes during installation and soil cover placement. Leakage tests were conducted using equipment developed at the Geotechnical Laboratory of the University of Brasília, applying hydrostatic pressures of 20 kPa, 100 kPa, 200 kPa, 400 kPa, and 800 kPa, equivalent to water heads ranging from 2 m to 80 m of water. The study has applications in geotechnical engineering projects such as dams, channels, and waste disposal areas, where leakage may occur under high pressures. The objective was to understand the factors that influence leakage rates and to develop methodologies to mitigate potential risks. The results showed that leakage intensity depends on various factors, including hydrostatic pressure, water temperature, and geometric characteristics of the damage (size and shape of the mechanical damage), which significantly affect the leakage rate. Larger damages tend to result in higher leakage compared to smaller ones, and hole damages appear to be more critical than linear cuts. The presence of sharp edges or irregularities in the damaged area can also influence leakage. PVC geomembrane barriers showed lower leakage compared with HDPE geomembranes. To mitigate leakage, it was observed that applying powdered bentonite under the geomembrane and in direct contact with the damage helped seal the leakage (using hydraulic barrier GM/GCL-D-F5). Therefore, understanding the behavior of PVC and HDPE geomembranes when subjected to mechanical damages is crucial for the design and performance of geosynthetic liner systems. Continued studies to minimize leakage rates through appropriate installation practices, material selection, and timely repairs are important to ensure the long-term effectiveness and reliability of geomembranes in various geotechnical applications

COMMITTEE MEMBERS:
Presidente - 404375 - ENNIO MARQUES PALMEIRA
Interno - 2517970 - GREGORIO LUIS SILVA ARAUJO
Externa à Instituição - Marias das Graças Gardoni Almeida