ASTM D 4623:2016

1.1 This test method covers the determination of the ambient local stresses (principal and secondary) in a rock mass and the equipment required to perform in situ stress tests using a three-component borehole deformation gauge (BDG) that was developed by the U.S. Bureau of Mines (USBM); see Note 1 . 1.2 The test procedure and method of data reduction are described, including the theoretical basis and assumptions involved in the calculations. 1.3 A section is included on troubleshooting equipment malfunctions. Note 1: The gauge used in this test method is commonly referred to by users as a USBM gauge (U.S. Bureau of Mines three-component borehole deformation gauge). 2 1.4 The values stated in inch-pound units are to be regarded as standard, except as noted below. The values given in parentheses are mathematical conversions to SI units, which are provided for information only and are not considered standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 1.5 This standard does not purport to address all of the safety problems, 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.