ASTM D 4506 : 2013 : EDT 1

1.1This test method is used to determine the in situ modulus of deformation of rock mass by subjecting a test chamber of circular cross section to uniformly distributed radial loading; the consequent rock displacements are measured, from which elastic or deformation moduli may be calculated. The anisotropic deformability of the rock can also be measured and information on time-dependent deformation may be obtained.

1.2This test method is based upon the procedures developed by the U.S. Bureau of Reclamation featuring long extensometers (1).² An alternative procedure is also available and is based on a reference bar (2). More information on radial jacking and its analysis is presented in References (3-8).

1.3Application of the test results is beyond the scope of this test method, but may be an integral part of some testing programs.

1.4Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. Reporting of test results in units other than inch-pound shall not be regarded as nonconformance with this test method.

1.5All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.

1.6This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.