Geological Science and Engineering

Geological Sciences and Geological Engineering
Geological Sciences and Geological Engineering

Geological Sciences and Geological Engineering Distinguished Speaker Program presents Dr. Navid Bahrani

On Thursday, May 13th, Dr. Navid Bahrani, Assistant Professor, Department of Civil and Resource Engineering, Dalhousie University, will be giving a talk for the Department of Geological Sciences and Geological Engineering.

Dr. Bahrani will be presenting on: "Advances in Micromechanical Modeling of Core Damage and Brittle Rock Failure"

Date: Thursday, May 13, 2021

Time: 12:30 pm EST

Zoom link:  Email dumondl@queensu.ca for the Zoom link

Please join us. All are welcome to attend!

Abstract: 

The Unconfined Compressive Strength (UCS) and the elastic modulus (E) are two fundamental rock mechanics parameters required at different design stages of any deep underground engineering project. This is the case for projects involving excavations in deep underground mines and geological repositories, and those requiring fluid flow at depth for the energy sector (e.g., deep geothermal boreholes). The standard procedure to determine these parameters is to perform laboratory tests on cored samples. The process of drilling may induce damage (micro-cracks) to the rock core, particularly in deep operations, due to the complex coring stress path. The presence of such micro-cracks may affect the properties of rock specimens measured in the laboratory. Therefore, the knowledge of the level of core damage (micro-crack density) and associated changes to the laboratory properties of rock specimens is of paramount importance for a reliable design of deep underground engineering projects. In this presentation, discontinuum numerical modeling approaches commonly used to simulate brittle rock failure, including the Bonded Particle Model (BPM) and the Bonded Block Model (BBM), will be introduced. It is demonstrated how these models can be used to simulate crack initiation and opening during coring and associated crack closure during laboratory compression tests. The influence of coring stress path on the level of core damage and associated changes to the rock strength and elastic modulus, and the implications for the determination of in situ stress magnitudes using core- and borehole-based measurement techniques will also be discussed in this presentation.