Measurement of rock-mass deformation properties by the borehole jacking method at the near-surface test facility

Borehole jacking tests have been conducted in an attempt to estimate the in situ deformation properties of Pomona basalt in the Near-Surface Test Facility (NSTF) on the Hanford Site, Washington. Full-scale heater tests are being conducted there as part of the feasibility study of radioactive waste disposal in basalt. The borehole jacking method obtains directionally oriented modulus values at depth in the rock mass. Seventy-six tests were conducted in two horizontal and four vertical boreholes.