Shrink-swell Properties Research Articles

A highlight of environmental and engineering geology in Fargo, North Dakota, USA

Several unfavorable environmental and engineering geologic conditions exist in Fargo, North Dakota. Dominantly, the behavior of smectitic clays within the proglacial Lake Agassiz sediments of the Sherack and Brenna Formations creates subsoil instability beneath engineered structures in the Fargo area and slope instability within cutbank meanders of the Red River of the North. Unfavorable engineering geologic conditions encountered include: the elastic deformation of clayey glaciolacustrine soils, shrink-swell properties, inadequate bearing capacities, and mass movements. These conditions are responsible for structural failures including the Fargo Grain Elevator in 1955 and the Northern Pacific railroad grade. Bank failures along the Red River are common due to the inherent instability of Brenna Formation smectitic clays which are subject to plastic deformation in the subsurface, with resultant block failure of overlying Sherack Formation. Recent alluvial sediments due to typical fluvial action and the continued seasonal saturation of cutbank meanders within the floodplain also add to soil instability.

A Petrographic Analysis of Extended Middle Missouri Ceramics from North Dakota

This article summarizes a petrographic analysis of ten thin sections prepared from Riggs and Fort Yates ware sherds (ca. A.D. 1200 to 1450), the first such study ever conducted on prehistoric ceramics collected in North Dakota. The procedure identified, described, and estimated the percentage of observable aplastics (coarser grained inclusions) and examined the geometric relationships between the aplastics and the encompassing clay matrix (micromass). Grit tempering was used exclusively in the manufacture of each vessel represented. The large and abundant polymineralic grains (rock fragments) are granodioritic in composition and evince local tills as the most likely source for the temper. The mineral composition of the aplastics and the matrix is consistent with raw material resources readily available in central North Dakota. The overall abundance and coarseness of the tempering agent is likely added to mitigate the high shrink-swell capacity inherent in the montmorillonite clays that are prevalent throughout the region. The size, amount, and composition of the temper grains are also common to vessels manufactured for utilitarian (culinary) purposes. It was not possible in this study to distinguish Riggs from Fort Yates ware at the microscopic level.

Porosity and available water of temporarily waterlogged soils in a Quercus robur (L.) declining stand

Pedunculate oak (Quercus robur L.) is particularly sensitive to decline in clayey soils presenting a high-perched temporary water table. These soils induce two successive constraints in one-year cycle: water excess (and hypoxy) in winter and early spring, and water shortage in summer (water stress being more restrictive to oak). We determined the porosity and water properties of temporarily waterlogged clayey soils supporting forest stands of declining Quercus robur trees in a 101 yr-old oak stand in Belgium (50 degrees 06'N 4 degrees 16'E). Roots unevenly colonized the soil down to 1.6 in: fine roots (diameter < 5 mm) were mostly distributed on the surface horizons (0-0.3 in) and around 1.3 in deep, despite dense clayey horizons appearing at 0.35 in depth. Clay content below this depth reached 46-51%. Illite and vermiculite were the dominant clay minerals. The clayey horizons exhibited marked shrink-swell properties: bulk density at 30 kPa increased from 1.41 to 1.88 g cm(-3) from the surface to 2 m depth. There was also evidence of hypoxic conditions caused by water saturation of pore space in the rooting zone from October to mid-April. Extractable water (EW), calculated between moisture tensions of 5 and 1600 kPa was 152.8 mm. The level of perched temporary water table strongly depended on the seasonal rhythm of water uptake by trees and on the shrink-swell behaviour of soil.

Self-similar solutions to problems on compaction and water recovery of clays while extracting water from strata

Infiltration of liquids in a stratum system and the deformation of surrounding rocks are known to be interrelated processes (see, i.e., [1]). In certain cases, such an interrelation is manifested especially clearly and, as a rule, is caused by the presence of insufficiently compacted clay layers contacting a header in use. While boring and exploiting a stratum, water flows in from clay layers compressed by overlying rocks. The softer the clay layer, the greater its strain and, therefore, the larger the ground shrinkage and the water yield from the stratum to the header. These effects were repeatedly observed in the practice of oil production and hydrogeology. Reiterated many-meter shrinkages were observed in the Wilmington [2] and Eckofisk [3] oil fields, in the process of the underground-water extraction in Mexico [2], etc. Balance calculations performed for the Belozerskiœ water-bearing complex [4] can serve as one more example. These calculations showed that the water inflow into a water-bearing stratum, which had been caused by compressing slightly permeable rocks surrounding the stratum, provides the predominant contribution to the water discharge rate.

Swelling–shrinkage properties and soil improvement of compacted expansive soil, Ning-Liang Highway, China

In this paper, the swelling–shrinkage properties of the compacted expansive soil in the Huaiyin Section of the Ning-Lian Highway are introduced, and swelling–shrinkage mechanisms are discussed based on changes in soil water content, dry density, material composition and fabric. The improvement of the compacted expansive soil by lime is also discussed briefly. It is concluded that careful attention should be paid to this type of compacted expansive soil.

Effect of Tillage and Plant Residue Management Practices on Shrinkage of a Vertisol

A study was carried out to determine the effects of different tillage and plant residue management practices on different soil moisture and shrink-swell properties of a Vertisol (very fine, semctitic, thermic, chromic Haploxerert (with less than 1 % slope). The core samples were collected in July (after harvesting of lentil) and in November (after planting of wheat) 1993. The two tillage methods were moldboard (T1) and chisel (T2). The two plant residue incorporation dates were in August (R1) and in October (R2). Results indicated that T2 tends to give higher water holding capacity and available moisture than T1. Immediate incorporation of plant residue (R1) tends to increase the bulk density and to decrease soil specific volume and void ratio when compared to late incorporation treatment (R2). In general, the two tillage treatments tend to decrease moisture availability, shrinkage characteristics, soil specific volume, and void ratio. They also tend to increase the soil shrinkage (subsidence and cracks volume) and bulk density. Chisel plough is recommended in Vertisols, if it is to be used before the rainfall.