Mining Contract: Development of Strength Criteria for Coal and Nonsedimentary Rock Masses and Investigation of Underground and Open Pit Mine Stability of Such Rock Masses

Summary of Results

This contract has six main objectives:

1. Investigate slope stability for an area in Asarco Ray open pit mine in Hayden, Arizona, through block theory, 3-D discontinuum numerical modeling, and slope deformation monitoring.
2. Develop a new rock mass strength criterion for rock masses having non-orthogonal fracture systems (applicable for rock masses in metal mines).
3. Develop a new rock mass strength criterion for rock masses having approximately orthogonal fracture systems (applicable for sedimentary rocks such as coal, shale, sandstone etc.).
4. Investigate the stability of tunnels in a coal mine in Pennsylvania through 3-D discontinuum numerical modeling and deformation monitoring around tunnels.
5. Investigate the stability of tunnels in Xiezhuang coal mine in China through 3-D discontinuum numerical modeling and deformation monitoring around tunnels.
6. Investigate the stability of tunnels in a metal mine in China through 3-D discontinuum numerical modeling and deformation monitoring around tunnels.

Results of these studies should provide a wealth of information for designing and constructing mining and civil engineering geotechnical systems that are in or on discontinuous rock masses, such as excavations made for mineral extraction, tunnels for hydropower and transport, dams, foundations, natural and man-made slopes, underground caverns for oil and gas storage, and hazardous waste isolation caverns. It is expected that this research will lead to completion of seven PhD dissertations. The research findings will be disseminated in journals and conference proceedings.