Research Project Title: Experimental and Computational Investigation of Fracture Propagation in Rocks

This research position is available to start in Spring 2018 (January 9, 2018) and support for pursuit of a PhD degree in Civil and Environmental Engineering with a focus on Geotechnical Engineering will be provided.

Faculty Advisors: Dr. Reza Hedayat and Dr. Vaughan Griffiths, Colorado School of Mines

Contact Information: Please feel free to contact Dr. Reza Hedayat at hedayat@mines.edu

Colorado School of Mines Application Procedure: http://www.mines.edu/Application_GS

Application Deadline: October 1, 2017

Project Overview

A thorough understanding of why, when and where rock fractures initiate, propagate and coalesce is of critical importance in the stability of rock structures such as slopes, foundations, and tunnels, as well as processes involving blasting and hydraulic fracture. This project will involve advanced laboratory testing of fracture in rock samples that will provide data on material behavior for use in computational models that can be used in a predictive capacity. The deliverables of this project will allow civil and geotechnical engineers to perform safer and more economical designs that will benefit society across a broad range of applications. The research will be integrated with educational and outreach activities. The interdisciplinary nature of this project, including experimental rock mechanics and computational geomechanics, will provide outstanding educational and training opportunities for undergraduate and graduate students at the Colorado School of Mines (CSM). The researchers will encourage the participation of underrepresented groups on this project, e.g. through the Society of Women Engineers (SWE) and Multicultural Engineering Program (MEP) student organizations on the CSM campus. They will also develop, implement, and assess instructional hands-on modules on materials behavior to be delivered during workshops. The research findings will be incorporated into graduate and undergraduate courses and disseminated through conference and journal articles.

The goal of this research project is to discover the fracturing characteristics of natural rocks with different pre-existing flaw geometries. The research objective is to formulate new experimentally verified crack initiation and propagation criteria that can be applied to different rocks with different flaw geometries for implementation in advanced numerical codes. A key innovation in this project is the combined mechanical-geophysical-numerical investigation of the fracturing processes in natural rocks. A comprehensive suite of uniaxial compression experiments will be conducted on granite, limestone, and sandstone with pre-existing flaws, with synergistic use of acoustic emission and active geophysical (ultrasonic) monitoring techniques. Based on experimental observations, new fracture initiation criteria will be developed and implemented in an eXtended Finite Element Method (XFEM) code to provide an entirely novel and potentially transformative numerical tool for assessment and prediction of fracturing in anisotropic rock formations.