Banca de DEFESA: RAISLA MARTINS DA SILVA GOMES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAISLA MARTINS DA SILVA GOMES
DATE: 10/06/2024
TIME: 08:00
LOCAL: Videoconferência - Microsoft Teams
TITLE:

Use of statistics as a tool for evaluating the resistance between interfaces with geomembranes and other materials.

KEY WORDS:

Geosynthetics, Geomembranes, Interfae strength, Statistical analyses, Soil-geosynthetic interaction, Pearson Matrix.

PAGES: 180
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

It’s notorious that in recent decades the use of geosynthetics in geotechnical works has grown.  Therefore, it’s of utmost importance to understand the behavior of these synthetic materials when they are in contact with other materials, a common situation in dams, landfills and canals.  To avoid accidents caused by sliding at the soil-geosynthetic interface it is essential to have knowledge of the behavior of this region, and this includes, in addition to the angle of friction of the interface, the configuration of the roughness of the geomembranes, the type of soil that will be placed in contact with the synthetic material, the stresses used during testing, among other factors.  The use of statistics to evaluate such parameters is applicable and relevant, since the ability of this technique to correlate variables contributes to increase the assertiveness of the evaluation of interface strength test data, such as conventional direct shear (CDC) and inclined plane (PI), which were analyzed in this dissertation. For this purpose, a database focused on the variables that influence interface resistance was assembled based on the literature. Two main interface types were studied in this research, namely sand-geomembrane (SG) and geotextile-geomembrane (GG) interfaces. For the interfaces with sand, 12 numerical variables and one categorical variable related to the type of manufacturing of the geomembranes were evaluated. On the other hand, for the interfaces with geotextiles, 07 numerical variables and also a categorical variable related to the manufacturing material of the geomembrane were evaluated. With the statistics used in this research it was possible to obtain answers related to the behavior of the means, standard deviations, coefficients of variation, medians, asymmetries, kurtosis, interquartile ranges and outliers of the database prepared in this study. These statistical analyses were performed based on a routine developed with the Python language, applying mainly the libraries Panda, Numpy and Matplotlib. Excel was also used for simpler analyses. With the present research it was possible to contribute to the expansion of the subject about the statistical analysis applied to the study of the sand-geomembrane and geotextile-geomembrane interface resistance, and to statistically understand, through Pearson's matrix, which was also obtained through Python routines, which parameters most influenced the interface friction angle (fint), considering the database used in this study. It was observed that for the CDC-SG and CDC-GG interface, the variables that presented the highest positive correlations were the soil friction angle (s) and the geomembrane roughness height (hG), respectively. On the other hand, for the PI-SG and PI-GG interface, the highest and most positive correlations were obtained for the variables the geomembrane roughness height (hG) and contact area (AC), respectively.

COMMITTEE MEMBERS:
Presidente - 2517970 - GREGORIO LUIS SILVA ARAUJO
Interno - ***.412.547-** - ENNIO MARQUES PALMEIRA - UOX
Interno - 1122864 - RENATO PINTO DA CUNHA
Externo à Instituição - FAGNER ALEXANDRE NUNES DE FRANÇA - UFRN