Publication Date
5-2024
Date of Final Oral Examination (Defense)
4-9-2024
Type of Culminating Activity
Thesis
Degree Title
Master of Science in Civil Engineering
Department Filter
Civil Engineering
Department
Civil Engineering
Supervisory Committee Chair
Nick Hyduma, Ph.D., P.E.
Supervisory Committee Member
Bhaskar Chittoori, Ph.D., P.E.
Supervisory Committee Member
Mojtaba Sadegh, Ph.D.
Supervisory Committee Member
Alan Harris, Ph.D.
Abstract
Porosity, which measures the empty spaces within rock structures, is crucial for determining properties like density, hydraulic conductivity, and mechanical strength, covering both microporosity and macroporosity. While many studies have explored how porosity affects compressive strength and stiffness in different rock types, less attention has been paid to its influence on tensile strength, especially in extrusive igneous formations like vesicular basalt. This research aims to fill this gap by investigating the relationship between macroporosity and tensile strength in vesicular basalt.
The study employed non-destructive techniques, including machine learning and manual image analysis, to calculate porosity, dividing it into specimen porosity and failure plane porosity. Specimen porosity was determined using the specific gravity method with a constant of 3.0 and a modified Segment Anything Model (SAM) for image segmentation. Failure plane porosity was evaluated using SAM on stitched and focused stacked images, along with manual calculations using IC Measure software.
Comparison between specific gravity calculations and SAM reveals that while specific gravity estimates both micro- and macroporosity, SAM only identifies macroporosities on the specimen's surface. Both methods generally yield similar results for lower porosity values but diverge at higher levels. SAM-estimated porosities exhibit a stronger correlation with tensile strength than specific gravity porosities due to SAM's tendency to produce higher porosity estimates for specimens with similar tensile strengths. However, surface porosity is considered unreliable for estimating specimen porosity due to the heterogeneous nature of macropores.
Fourteen specimens underwent extensive examination to evaluate failure plane porosity, encompassing the entire dataset from specific gravity measurements. Techniques such as image stitching and focused stacking were employed to generate detailed images of the failure plane. Porosity determination methods were compared for consistency, with a baseline of a ±5% porosity range. SAM-assessed failure plane porosities generally matched well with manually measured porosity, except for a few instances where issues like double counting of macropores led to discrepancies in porosity values.
The correlation between failure plane porosity and tensile strength was analyzed, revealing a much stronger correlation compared to specimen porosity as determined by specific gravity methods. Various methods of assessing failure plane porosity were compared, with SAM assessment showing similar results to manual measurement.
DOI
https://doi.org/10.18122/td.2180.boisestate
Recommended Citation
Mazzagotte, James C. III, "Developing Relationships Between Macroporosity and Tensile Strength by Imaging Failure Planes" (2024). Boise State University Theses and Dissertations. 2180.
https://doi.org/10.18122/td.2180.boisestate
