DUSEL Geotechnical Study
Providing geotechnical services to understand rock properties for transitioning Homestake Mine to the Deep Underground Science and Engineering Laboratory (DUSEL) facility.
To help acquire and adapt the Homestake property for scientific purposes, the South Dakota Science and Technology Authority (SDSTA) developed a plan to refurbish the mine facilities, a management plan to facilitate transitioning to the Deep Underground Science and Engineering Laboratory (DUSEL), and an operations plan for the first 5 years. The management plan identified the 4850 Level of the former Homestake Mine as the prime level for the DUSEL campus, where excavated laboratory modules and large cavities will host a variety of sensitive scientific experiments.
RESPEC was awarded a contract to conduct geotechnical investigations that provided the basis for a Preliminary Design Report on the facilities and experiments for DUSEL. The objectives of the geotechnical investigations were to (1) provide a better understanding of the rock properties, (2) characterize the rock mass in which these excavations are planned, (3) establish parameters and recommendations for the rock excavation design work, and (4) provide geotechnical data that can be used to evaluate potential impacts that phased construction will have on the stability of adjacent rock.
This investigation was critical to ensure both personnel safety and equipment protection during the transition process, and it provided the necessary data to evaluate the long-term stability of all of the underground facilities. RESPEC addressed these objectives by performing the following six tasks:
1. Geological mapping of selected areas of the Homestake Mine
2. Reconnaissance-level drilling and core logging
3. Optical and acoustic televiewer logging of the drill holes
4. In situ stress measurements performed in the drill holes
5. Laboratory testing of the retrieved core
6. Numerical modeling of proposed underground excavations.
RESPEC was the project team leader and provided an engineer on site daily to oversee all activities. Specifically, RESPEC assisted in the geological mapping and solely performed the laboratory testing and numerical modeling. RESPEC was also responsible for final deliverables, which included a report that summarized the results of the geotechnical investigation and the acquired dataset. This work was performed under the direction of the South Dakota School of Mines & Technology. Team member Arup also worked on the DUSEL project as part of the $500 million contract for the site design and infrastructure.