Standard Test Method for Determining In Situ Modulus of Deformation of a Rock Mass Using the Radial Jacking Test

Importancia y uso:

5.1 Data on the response of a rock mass to in situ loading provides essential information for many purposes in the science of rock mechanics, in the construction of dams, tunnels, bridges, high-rise structures, and other facilities that exert pressure on the foundation material or surrounding rock mass.

5.2 This test method is similar to a pressuremeter or dilatometer test in rock boreholes. The most significant difference is it engages a much larger volume of the rock mass. By testing a larger rock volume, the influence of discontinuities and other geologic factors on rock mass response to loading is more accurately determined. (Fig. 3)

FIG. 3 Modulus of Rock Mass

Radial jacking test engages a larger volume of the rock mass than with other test method options, such as laboratory (E_lab) and borehole tests other than some geophysical borehole and cross-hole tests.

5.3 This test method should be used when values are required which represent the rock mass properties more accurately than can be obtained through less expensive uniaxial jacking tests, laboratory, or other test methods or procedures. Also, it could be valuable for obtaining such data before or after computer modeling to verify and fine-tune any computer model output.

5.4 Examples of when this test method would be useful is to design pressurized unlined or lined tunnels and shafts.

Note 4: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

Subcomité:

D18.12

Referida por:

D0420-18

Volúmen:

04.08

Número ICS:

93.020 (Earth works. Excavations. Foundation construction. Underground works)

Palabras clave:

discontinuities; in situ test; loading tests; radial jacking test; rock; pressure;