An automated test facility for rock mechanics research

Abstract

This paper describes the design, development and operation of a newly completed test facility in the Department of Mining Rock Mechanics Laboratory at The Pennsylvania State University. The facility contains an electronically programmed electro-hydraulic loading system capable of developing compressive and tensile loads of up to 200,000 and 120,000 lb respectively. Programming facilities available make it possible to carry out creep, stress relaxation and fatigue studies as well as experiments under controlled rates of loads strain and deformation. Two hydraulic power supplies are included for developing confining and pore (internal) pressures during triaxial loading experiments. Facilities are available for monitoring strains, loads, pressures and temperatures; these include a digital data acquisition system capable of monitoring up to 200 channels of experimental data at a rate of 20 channels/sec, and three dual-channel strip chart recorders and an X-Y plotter which allow continuous recording of selected variables. The overall facility has been developed for routine use by faculty and graduate students. Although considerable time and effort have been expended in designing the facility, it is expected that the convenience and reliability inherent in such a facility will accelerate rock mechanics research many fold. Research projects presently utilizing the new facilities include studies of incremental creep, and fatigue in geologic materials.