This proposal coordinates the efforts of several geomechanics investigators planned at the Deep Underground Science and Engineering Laboratory (DUSEL) facility at Homestake Mine. The project will provide a framework that will allow construction and operational decisions to be made efficiently while ensuring that important design parameters are obtained. At present, knowledge of the characteristics of rock masses and, particularly the capability to predict the performance of underground openings are limited. This limitation is caused by the lack of three dimensional exposure, the related difficulty to know what is in the rock mass and the lacking knowledge of the basic behavior of discontinuous media such as rock masses. At DUSEL it will be possible to use existing and new rock mass exposure/exploration to develop rock mass models and to then compare them to reality when construction occurs. Since construction occurs in stages it will be possible to verify and improve the models in stages. It is also very likely that doing all this together with other scientists and engineers will lead to innovative thinking about engineering problems. DUSEL provides the absolutely unique opportunity to further science and engineering both in research and education. Underground construction, be that for civil purposes (transportation, storage, utilities, possibly habitation) or for mining, is very costly and time consuming. The proposed research will lead to innovations, which have the potential for significant cost and time savings while maintaining or increasing safety.
Award No.: 0918571 By H. H. Einstein, Antonio Bobet The main goal of DUSEL was to use the existing mine facilities at Homestake Mine SD and expand them as needed, such as excavating large caverns, to run particle physics experiments. After its start as a physics endeavor, it was expanded to also include other domains, which would benefit from working in the deep underground environment. Consequently, BGE (Biology, Geology, Engineering) with interest areas such as, Ecohydrology of fractured rock, Carbon Sequestration, coupled THMCB processes, fault moments and engineering performance of rock masses and underground caverns were included. The Cavern Design project was one of the BGE projects, in which research concepts were to be developed, which would then be included in the major (S-5) proposal for DUSEL. However, NSF decided to discontinue this process, although it is still possible that individual projects may be funded. Given this situation, the objectives of the Cavern Design project were somewhat changed. Specifically, the information collected and evaluated was summarized in a final report, rather than serving as a basis for the S-5 proposals. This will allow the involved researchers, other interested researchers and funding agencies to further develop what is of interest. This is particularly so since cost estimates were prepared by all participants. The Cavern Design Project specifically included: Project 1 - Fracture Network Characterization Project 2 - Use of LIDAR and Digital Photogrammetry for Digital-Terrain-Model Reconstruction of Tunnel Walls Project 3 - New Models For Geomechanical Characterization in Underground Engineering Project 4 – Stochastic Characterization of Rock Mass Properties Project 5 - Stability Contour Map For Optimizing the Locations of DUSEL Caverns Project 6 - Geomechanical and Geophysical Evaluation of Damage Mechanisms from Large-Scale Cavities in Anisotropic Rock across Multiple Time Scales Project 7 - Cavern Design and Monitoring Project 8 - Use of Novel Excavation or Cutting Techniques for Stress Relieve in The Large Caverns Project 9 - Scale Effect and Mine-By Experiments Project 10 – Risk Assessment Project 11 – Mine Pillar Scale Effect Project 12 – Engineering Fractures in Discontinuous Rocks All this was to be implemented in the context of the extended observational method, in which the research would benefit both the advancement of knowledge and the practical design and construction of the new research conclusions. The total estimated amount for performing this research is $520,500,000. The proposed research both in its approach (extended observational method) and through the substance of the proposed work provides a way of learning more about rock mass characteristics and performance while simultaneously aiding design and construction of the large experimental caverns and other underground facilities. In this way it would have a far reaching impact both on the science and engineering of rock masses. The intellectual merit is not only in the substantially advanced knowledge but, very importantly, in the integration of science and engineering. The final report, therefore, includes a "coordination table" that shows how the different BGE projects might interact.