Relationship between macroporosity and Young’s modulus through UCS tests on rock and analogue models, and numerical modeling – a literature review

It is well known that rock porosity reduces rock Young’s modulus of intact rock specimens. However, it is not well understood how different types and amount of macroporosity in forms of non-connected or isolated cavities (e.g., vesicular basalt, lithophysal tuff) or interconnected vugs (e.g., vuggy limestone) affect rock elastic properties. Such macroporosity leads to challenges in deriving engineering properties of rock. This paper compiles an existing database for porosity and Young’s modulus of macroporous rocks. The database includes Young’s modulus determined from unconfined compression testing on intact rock specimens and analogue specimens used to prepare rock-like test samples and numerical simulations of compression testing on similar materials. The database is used to develop the relationship between porosity and Young’s modulus. In addition to the porosity, the macropore shapes, sizes, locations, and proximity of a macropore to its neighboring macropore play a role in how porosity affects intact rock Young’s modulus.