ASTM D4553-18 PDF Download

The standard test procedure, ASTM D4553-18, focuses on identifying the in situ creep properties of rock. A rock mass under load can have its time-dependent deformation characteristics predicted using the test data acquired using this method. Typically, this test is necessary for certain rock types or expected loads. It may also be helpful in structural design analyses that incorporate long-term loading.

The test is carried out outside at room temperature; however, it can be altered to test at different temperatures if necessary. The test's findings can be used to validate assessments of structural mathematical modelling and laboratory creep data. Under a nonuniform condition of tension and beneath a rigid plate, the creep properties of the rock mass are calculated.

A field inquiry must be followed by an in-situ creep test if time-dependent characteristics are found. It is crucial to remember that the accuracy of the findings generated by this standard depends on the skill of the individuals conducting the test and the suitability of the facilities and equipment employed. Compliance with Practise D3740, which specifies standards for competent and objective testing, does not ensure accurate outcomes because there are a number of variables at play.

The preparation, tools, testing technique, and data documentation for carrying out the in situ creep test with a rigid plate loading method are also specified in the standard. Although the test is typically carried out in an adit or small chamber underground, adequate modifications can be made for testing on the surface. The predicted axis of thrust or other application-specific factors will define the test's orientation. Flexible plate apparatus can be employed if the projected creep displacement is within the flat jacks' travel tolerance.

Unless this test technique supersedes significant digit rules and rounding processes, all observed and calculated values must adhere to Practise D6026. When comparing results to the stated limitations, values should be rounded to the nearest significant decimal number of digits. However, the test method does not take into account user objectives or material variation, even though it is customary to change significant numbers in reported results to take these factors into account. Depending on whether inch-pound calculations or dynamic calculations are being utilised, the standard also offers information on the units that should be employed.