DUSEL Experiment Development and Coordination (DEDC) Internal Design Review July 16-18, 2008 Steve Elliott, Derek Elsworth, Daniela Leitner, Larry Murdoch, Tullis C. Onstott and Hank Sobel

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Underground Construction & Mining Cavern Design (16) H. Einstein (MIT), A. Bobet, L. Pyrak-Nolte (Purdue University), C. Laughton (FERMI Lab), M. Kuchta (Colorado School of Mines), W. Pariseau, J. Donovan (University of Utah), M. Mauldon (Virginia Tech), U. Ozbay (Colorado School of Mines), F. Tonon (University of Texas, Austin), R. Sousa (Lachel, Felice and Assoc), G. Callahan (RESPEC), P. Kulatilake (University of Arizona), E. Asa (North Dakota State), J. Rostami (Penn State),S. Glaser (UC Berkeley) Cavern Production (17) P. Cundall, C. Fairhurst (UMN/Itasca), J. Furtney (Itasca), E. Detournay, B. Guzina, J. Labuz, S. Mogilevskaya, R. Ballarini (UMN), R. Jeffrey (CSIRO), L. Petersen (CNA Engineers), H. Huang, L. Germanovich (Georgia Tech), M. Kuchta (Colorado School of Mines), Z. Hladysz (SDSM), M. Ge, D. Elsworth (Penn State), C. Dowding (Northwestern) Petersen 1999

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Science Objectives: (i) fully integrate knowledge into the design and construction of a cavern (ii) develop and control fracture of rock through preconditioning and blasting studies Why DUSEL? Large in-situ stress, fractured rock mass, and large scale excavation Chen & Labuz 2006

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Science Why is it important to do these experiments? The community will have access to underground facilities dedicated to fundamental research on completing engineered structures—preventing failure of the rock mass—and on controlling underground operations for removal of rock and production of resources— promoting failure of the rock. Expected results and their significance: Provide design guidelines for the large scale Excavate quickly, efficiently, and controlled

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Proposed Experiments (Describe A+ Experiments in multiple slides: maybe 1 to 5 slides) Cavern Design Predesign Construction Long-term performance

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Proposed Experiments (Describe A+ Experiments in multiple slides: maybe 1 to 5 slides) Cavern Production: Preconditioning & hydraulic fracturing (quasi-static load) Optimization of blasting (dynamic loading)

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Proposed Experiments (Describe A+ Experiments in multiple slides: maybe 1 to 5 slides) The experiments will consist of several stages: 1. Analyses of fracture treatments 2. Characterization of local conditions 3. Installation of monitoring sensors 4. Mobilization of fracturing equipment 5. Fracturing / blasting and response 6. Post-fracture characterization 7. Mine through and mapping 8. Analytical and numerical modeling 9. Supporting laboratory experiments 10. Education and outreach E26 E48 Surface RL 10280m Undercut level RL 9700m Previous Mine through site

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Facility Needs Facilities Rock volume that will be mined; approx 25 x 25 x 25 m Main fracturing pump, 50 MPa and 300 liters per minute Water supply of 10,000 liters per fracture 10 boreholes for monitoring ahead of the fracture 12 holes, 10 m deep, tiltmeters Microseismic array able detect to -3 magnitude events 6 boreholes for cross hole tomography Digital photogrammetric system

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Facility Needs E&O Virtual lab Demonstration of instability—toy load frame Potential Problems Drilling and rig delays Poor hole quality from high stress Mine through carried out too quickly, not allowing full mapping and sampling

Homestake DUSEL Initial Suite of ExperimentsDUSEL Experiment Development and Coordination Schedule Development Needs Common access to Vulcan, the database and display system containing existing Homestake mine data S-4 activities Workshops Site visit Prelim modeling Hydraulic fracture Natural fracture