Doctoral Dissertations

Keywords and Phrases

Joint persistence; Lattice-Spring-based Synthetic Rock Mass; Numerical modelling; Rock bridge; Rock mechanics; Slope stability

Abstract

"Rock bridges were defined as a segment of intact rock that separates from discontinuities. Numerous studies are focused on developing methods to quantify their significance in rock mass strength and deformability behavior. This thesis aimed to enhance understanding of the effect of rock bridges on jointed rock masses in both laboratory and slope scales. For this purpose, the lattice spring base Synthetic Rock Mass (LS-SRM) method was adopted to conduct the numerical models, distinguished in computational efficiency, and simulates the brittle failure and roughness of discontinuities.

A robust approach was developed to optimize the calibration procedure to avoid the complex and time-consuming trial-and-error process utilizing the Response Surface Methodology (RSM). The results of direct shear models reveal that the LS-SRM method effectively replicates the failure mechanisms and peak shear strength of pre-existing rough two flows rock-like specimens with coplanar and non-coplanar rock bridges. As the normal stress levels increased, the propagation of tensile wing cracks was restricted. The results of direct shear models with joint filling indicated that the filling materials mainly affected the shear strength of the specimens when the filling thickness was 4.0 mm and above. The shear band horsetail formations were efficiently simulated using the LS-SRM approach, with results matching very well with natural phenomena. Slopes with non-persistent joints are producing smaller and shallower mobilizing zones compared to slopes with fully persistent joints. A higher factor of safety and deeper failure zones at the first unstable conditions are observed in slopes with higher joint spacings. A joint persistence factor of below 0.67 had no apparent effect on the slope stability"--Abstract, p. iv

Advisor(s)

Sherizadeh, Taghi

Committee Member(s)

Maerz, Norbert H.
Rogers, J. David
Liu, Kelly H.
Emdadi, Arezoo

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

Ph. D. in Geological Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2021

Pagination

xix, 168 pages

Note about bibliography

Includes_bibliographical_references_(pages 164-167)

Rights

© 2021 Mariam Salem Alebayat, All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12213

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