Pores—The Almost Invisible Part of Soil

Abstract

Notwithstanding the fact that up to 50 % or more of the volume of many soils consists of pores, the manner in which the pores are characterized, described, quantified, and information about them is utilized in describing the expected behavior of a soil compared to what is done for particles in the same soil is effectively nonexistent. In many cases, the pore aspect of the soil is described by a single value such as void ratio or porosity and as such, the richness that pores bring to the overall soil response is not captured. This lack of detail and specificity about pores and their properties is largely due to historical vestiges of how such properties are studied. In the physical or analog world, particles are much more tangible than pores and thus are easier to focus on and characterize using mechanical processes. This relative tangibility in the analog world has not changed today, however, what has changed are the range of techniques and tools that we have available which allow us to conduct many of these studies on a digital replica of the soil. In this transformed space, pores are equally as tangible as particles. This paper explores how this situation has evolved with the introduction of new approaches that are now available to study all aspects of soils equitably and where the role of pores in soil response can be readily studied and quantified in a manner similar to that of particles.