Engineering geology aspects for design and classification - Tunnel Engineering: Basics and Additional Services for Design and Construction - page 33

2.3.2 Rock mechanics investigations
Task. Rock mechanics investigations mainly have the aim of determining the following
rock properties:
- Elasticity.
- Strength.
- Primary stress state.
- Permeability.
- Solubility.
- Swelling propensity.
- Determination of the loosened zones to be expected around the perimeter of the cavity
after excavation.
These parameters form the basis for determination of the free stand-up time of the rock
mass, for planning of the construction process, structural calculations, design of the lining
and support measures, determination of the deformation or settlement to be expected and
the specification of in-situ measurements.
Investigation methods. The most important rock mechanics methods for the determina-
tion of rock properties are given in Table 2-6 (page 34).