ABSTRACT
Most rock testing is at the small scale. This is true of testing in field exposures, when logging rock core, down boreholes and in the laboratory. Rock-engineering design however needs to deal with large-scale geological and geotechnical units, with parameters assigned appropriately; such units are not usually testable themselves. Some properties can be measured at a larger scale indirectly via geophysics, by fluid-pumping tests or by using very expensive testing setups such as those employed in bored pile testing. Parameters are also derived by back analysis of the response of rock to excavation or loading beneath major structures or in response to fluid extraction (usually water, oil or gas). The measurement of hydrogeological parameters is discussed in more detail in Chapter 4.
