Creep testing of salt: procedures, problems and suggestions

摘要: Apparatus and procedures were described for salt testing to 70 MPa confining pressure 250/sup 0/C with emphasis on the evaluation of rock creep. Descriptions hardware, data reduction fitting presented particular consideration methods which ensure consistency objectivity in analyses. Difficulties discussed bear validity interpretation creep measurements. End-effects evaluated by means finite element calculations. Preliminary results two cases indicate reasonably homogeneous stress strain conditions more than 20 percent specimen shortening. This observation suggests a minimal influence boundary conditions. Various difficulties measurements helped explain wide scatter published elastic constants natural salt. Measurement good resolution radial strains cylindrical samples deemed important accelerating Finally, problems identifying secondary consequences overload hardening considered way examples experiments poor control. The many gathering unambiguous concerning prompted suggestions detailed test documentation publications possible reference under standardized