Silty sand

It is intended that a spread foundation be designed for a concentric load of 300,000 lb (dead load plus live load). This foundation is to be placed on the surface (brown silty sand and gravel) of the soil and bedrock column shown in Figure 2-61. If a square foundation can be made to support the 300,000-lb load, what should be the dimensions of this foundation ... 

The injection zone consisted of multiple Upper Cretaceous strata of sand, silty sand, clay, and some thin beds of limestone (see Figure 20.14). The clay confining layer was about 30 m (100 ft) thick. 

Finer-grained materials such as silts and clayey silts are typically used for monolithic ET cover systems and the top layer of a capillary barrier ET cover system because they contain finer particles and provide a greater storage capacity than sandy soils. Sandy soils are typically used for the bottom layer of the capillary barrier cover system to provide a contrast in unsaturated hydraulic properties between the two layers. Many ET covers are constructed of soils that include clay loam, silty loam, silty sand, clays, and sandy loam. 

Cover design The ET cover was installed in 1999 and consists of a 3-ft silty sand/clayey sand layer, which overlies a 2-ft foundation layer. The cover soil was placed in 18-in. lifts and compacted to 95% with a permeability of <3 x 10 5 cm/s. Native vegetation was planted, including artemesia, salvia, lupines, sugar bush, poppy, and grasses. 

S Moderate Permeability Soil (Silty Sand) t — ] Low Permeability Soil (Clay and Silt) Water Table... 

Use of these equations to predict future production from a recovery project is described by the following example. An abandoned refinery property is being dismantled and the underlying aquifer remediated. Substantial LNAPL product accumulations occurred overlying the fine silty sand aquifer. Preliminary investigation indicated that a four-well system would effectively remove most of the product within a reasonable time at a modest cost. The production rate over time is illustrated in Figure 11.4. Peak production occurred on day 78 of operation, then declined. Final measurement occurred on day 141. 

The site is underlain by a sequence of unconsolidated, stratified, laterally discontinuous deposits of sand, silty sand, clayey silt, and silty clay of Recent and Upper Pleistocene age. A thin veneer of Recent deposits immediately underlies the eastern portion of the site. These deposits are difficult to distinguish from the underlying Upper Pleistocene deposits, which comprise the lower portion of the Lakewood Formation, due to similarities in lithology. 

Relatively moderate permeability, poorly sorted silty sand. 

Brown s Lake silty clay), 5.05 (Hamlet City Lake silty sand), 4.16 (Vicksburg, MS silt) (Brannon et al, 1995)... 

Convenience store 7,000 Groundwater and soil—fine to silty sand 21 100,000... 

Figure 7.25 shows the position of five Leg 204 drill sites. The off-summit Site 1245 intersects an unusual horizon marked A extending from about 1600 to 1400 m (although not shown here, this fault does extend to the summit). This silty sand horizon is important because its porosity and permeability allows for rapid... 

Gerlach, S., 1978. Food-chain relationships in subtidal silty sand marine sediments and the role of meiofauna in stimulating bacterial productivity. Oecologia (Berl.), 33 55-69. 

E24369 681C-9-4, 30-37 77.3 Quaternary mud, silt, silty sand 0.53 17 + 2... 

Below Unit B a silty sand layer (Unit C) was encountered in the cores taken between the mouth of the Great Wadi and the center of the Kom el Ahmr. Unit C contained a sequence of Old Kingdom to late Predynastic artifacts dating from about 2500 B.C. to 3200 B.C. Below Unit C, a very compact, well-sorted thick layer of Nile clay and sand was encountered (Unit N). No cores or trenches reached below this sedimentary deposit. Unit N contained occasional Predynastic ceramic and flint artifacts. Samples were collected from each 10-15-cm auger cut within each sedimentary unit in each core or trench. In addition, numerous samples of the Neonile deposits and other sediments from the nearby low desert and Great Wadi were taken for analysis. 

The modeled concentration lines in Figure 8 are for a combination of a coarse sand (2/3 of aquifer thickness) and silty sand (1/3 of thickness). The higher initial exchange capacity of the silty sand increases the retardation, and smears out the concentration pattern. This does fit the observed slow increase to the final concentration in the first run, but the modeled pattern is too steep for the seventh run. It may be that the pattern is more spread out in the field because in the aquifer more layers exist with a different initial exchange capacity than in the simple two-units model. Such differences will lead to a faster initial breakthrough, and to a more retarded arrival of the... 

The raffinate is to be released to compacted-clay-lined evaporation ponds constructed in local sandstone and silty-sand formations. These formations contain a few percent of clays such as kaolinite and smaller amounts of calcite cement. You are asked to evaluate the capacity of the rock to neutralize the raffinate acid-... 

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