Field measurements of soil cracks

Abstract

Shrink–swell soils, often classified as Vertisols or vertic intergrades, are found world‐wide and are a leading cause of damage to infrastructure such as buildings, roads, and pipelines. Crack networks act as dominant environmental controls on the movement of water, contaminants, and gases. Numerous methods have been proposed to quantify the size (e.g., width, depth, volume) and connectivity of individual cracks and of larger crack networks. To measure and quantify the size and variability of cracks, we focus on two nondestructive methods, called here the tape and rod and displacement approaches, and one destructive method, called here the cast and excavate protocol. The nondestructive methods are relatively inexpensive and can allow repeated measurements, which makes them conducive to use in larger environmental studies such as observing hydrological partitioning between infiltration and surface runoff. However, the nondestructive methods are often biased toward larger cracks (due to physical limitations on the crack sizes that can be measured), require assumptions of crack geometry to determine crack volumes, and typically do not provide information on subsurface connections between cracks. The destructive cast and excavate method is better suited to sample aoftentimes can only be used once (precluding repeated measurements) and is labor intensive. A combination of measurements may therefore be required to best understand crack dynamics in both time and space. Altogether, the methods surveyed here enable accurate measurement and quantification of soil crack characteristics.

Changes in crack width on the surface of heavy soils during drought, determined by precise measurement and calculation

“…For measuring the width of cracks, standard devices are used, the common advantage of which is automatic operation. Their review is presented in studies (Stewart and Najm, 2020;Tang et al, 2021). None of these devices were available at our workplace.…”

“…The crack network forms a system of preferred water flow paths in both horizontal (horizontal conductivity of cracks) and vertical (vertical conductivity of cracks) direction. Cracks geometry changes in time and therefore hydraulic parameters of the preferred paths change as well (Chertkov, 2001;2002;Chertkov and Ravina, 1999;2011;Stewart and Najm, 2020). Open water level in cracks can exist only if they are still open.…”

Climate Data to Predict Geometry of Cracks in Expansive Soils in a Tropical Semiarid Region

“…The measurements were taken with the aid of a caliper, a ruler, small vegetable rods and a laser distance meter. The volume of the cracks was evaluated assuming a parallelepiped form [20], being the product of the area of the crack by its depth (data available as Supplementary Materials).…”

Fractal Characteristics of Natural Fiber-Reinforced Soil in Arid Climate Due to Cracking

“…The drying process in soil is governed by interactions between soil and the atmosphere [20]. Soil cracks play an important role in the movement of water, pollutants, and gases by providing preferential channels for water filtration and solute transport [21][22][23]. At the same time, cracking can adversely affect the cohesion of soils [24].…”