Analysis of the internal structure of Brenna sandstone samples with respect to the differences in measured quasi‑elastic moduli

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68145535%3A_____%2F24%3A00585109" target="_blank" >RIV/68145535:_____/24:00585109 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/article/10.1007/s00603-024-03828-3" target="_blank" >https://link.springer.com/article/10.1007/s00603-024-03828-3</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00603-024-03828-3" target="_blank" >10.1007/s00603-024-03828-3</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Analysis of the internal structure of Brenna sandstone samples with respect to the differences in measured quasi‑elastic moduli

Popis výsledku v původním jazyce

The Young’s modulus and Poisson’s ratio determined for the rocks under uniaxial or triaxial loading conditions represent necessary input parameters for solving many geotechnical tasks. However, these effective stiffness moduli, particularly the Poisson’s ratios, measured on different samples sometimes substantially differ, even for visually compact and macroscopically homogeneous rock. This has been observed for Brenna sandstone, especially under conditions of conventional triaxial extensions. The aim of this study was, thus, to reveal differences in rock structure that could cause such behavior. Several complementary methods were used to investigate the structure of this sandstone: X-ray computed tomography (CT), visual analysis using optical scanning and stereo-microscopy, and a new method combining water jet erosion with these visualization techniques. Analyses of this structure revealed mechanically more resistant compact thick and adjacent thin weak layers. In rock samples, these layers have different patterns and orientations. To demonstrate the influence of layer orientation on effective stiffness moduli measured under different loading conditions, FEM calculations were performed for idealized structural models. The outcomes of this numerical analysis are in qualitative agreement with the results of the loading experiments and the layered structure revealed in the samples. The ability of the proposed method using water erosion to analyze the rock structure in detail was verified. The method offers an interesting alternative to standard visual and X-ray CT techniques. The numerical calculations indicate the importance of latent layered defects in sedimentary rocks for fine measurements of stiffness moduli (especially the Poisson’s ratios) used as inputs for geotechnical applications.n

Název v anglickém jazyce

Analysis of the internal structure of Brenna sandstone samples with respect to the differences in measured quasi‑elastic moduli

Popis výsledku anglicky

The Young’s modulus and Poisson’s ratio determined for the rocks under uniaxial or triaxial loading conditions represent necessary input parameters for solving many geotechnical tasks. However, these effective stiffness moduli, particularly the Poisson’s ratios, measured on different samples sometimes substantially differ, even for visually compact and macroscopically homogeneous rock. This has been observed for Brenna sandstone, especially under conditions of conventional triaxial extensions. The aim of this study was, thus, to reveal differences in rock structure that could cause such behavior. Several complementary methods were used to investigate the structure of this sandstone: X-ray computed tomography (CT), visual analysis using optical scanning and stereo-microscopy, and a new method combining water jet erosion with these visualization techniques. Analyses of this structure revealed mechanically more resistant compact thick and adjacent thin weak layers. In rock samples, these layers have different patterns and orientations. To demonstrate the influence of layer orientation on effective stiffness moduli measured under different loading conditions, FEM calculations were performed for idealized structural models. The outcomes of this numerical analysis are in qualitative agreement with the results of the loading experiments and the layered structure revealed in the samples. The ability of the proposed method using water erosion to analyze the rock structure in detail was verified. The method offers an interesting alternative to standard visual and X-ray CT techniques. The numerical calculations indicate the importance of latent layered defects in sedimentary rocks for fine measurements of stiffness moduli (especially the Poisson’s ratios) used as inputs for geotechnical applications.n

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Rock Mechanics and Rock Engineering

ISSN

0723-2632

e-ISSN

1434-453X

Svazek periodika

57

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

22

Strana od-do

5913-5934

Kód UT WoS článku

001198584400003

EID výsledku v databázi Scopus

2-s2.0-85189624583