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The Geosphere and Geochemistry
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Several approaches are employed in surface mining. Sand and gravel located under water are extracted by dredging with draglines or chain buckets attached to large conveyers. In most cases, resources are covered with an overburden of earthen material that does not contain any of the resource that is being sought. This material must be removed as spoil. Open-pit mining is, as the name implies, a procedure in which gravel, building stone, iron ore, and other materials are simply dug from a big hole in the ground. Some of these pits, such as several from which copper ore has been taken in the United States, are truly enormous in size.
Bio-solution for global sand crisis and sustainable organic agriculture in desert states
Published in Zoltán Bartha, Tekla Szép, Katalin Lipták, Dóra Szendi, Entrepreneurship in the Raw Materials Sector, 2022
D. Štyriaková, I. Štyriaková, J. Šuba, Felix Föhre
Sand is one of the main components of the modern glass, foundry, refractory, ceramic and construction industries. In recent years, there has been a sharp increase in demand for high-purity quartz for semiconductor chips, solar batteries, photovoltaic and flat panel displays, which are classified as advanced technology products. Quartz is one of the most important raw materials used in many industries. There are four types of sand: river sand, sea sand, desert sand and machine-made sand. Desert sand, as the name suggests, is sand from the desert.
Shallow foundation settlement
Published in Rodrigo Salgado, The Engineering of Foundations, Slopes and Retaining Structures, 2022
Problem 9.20 The soil profile at a site consists of 5–7 m of a poorly graded, medium-dense, quartz dune sand (K0 = 0.43, γm = 16.4 kN/m3, and ϕc = 32°) overlying a weakly cemented limestone. The sand layer is of Holocene age and was formed from the chemical weathering (dissolution) of limestone with subsequent erosion, transportation, and re-deposition by wind. The water table is typically located at a depth of about 5.5 m, just above the limestone layer. P-Figure 9.7 shows the qc profile obtained from cone penetration testing performed at the site. A 1.5-meter-wide and 1.0-meter-thick square footing is embedded 1.0 m into the sand layer. The footing is not backfilled. Neglect the effect of creep and take the time factor as equal to 1. Using both Schmertmann’s method and Lee et al.’s method9: Plot the load–settlement curve of the footing up to a settlement of 100 mm.Compute the net unit load at the base of the footing for settlements of 25 and 50 mm.
Experimental and numerical comparative crashworthiness analysis of innovative renewable hybrid barrier with conventional roadside barriers
Published in International Journal of Crashworthiness, 2023
Halil Ibrahim Yumrutas, Sedat Ozcanan, Mustafa Yurdabal Apak, Mohammed Jalil Anwer
Sand is a soil material with natural, granular, and elastoplastic features and consists of crushed rock and mineral particles with a diameter ranging from 0.075 mm to 4.75 mm and a specific weight between 1.5 and 1.80 ton/m3. It is cohesionless when dry or saturated with water, but with optimum water content, it has a certain cohesion [44]. Studies in the literature reveal that sand has a high ability to absorb impact energy [45–48]. The grain size of the sand used in the RHBs is between 0.425 and 4.75 mm, and the unit weight is 1.60 ton/m3. As shown in Figure 8, the sand, which is a reusable material, was placed in bags inside RHBs to avoid a new accident due to the scattering of sand onto the road platform after any accident and to be able to re-use several times during service life of the barrier.
Valorization of uncontaminated dredged marine sediment through sand substitution in marine grade concrete
Published in European Journal of Environmental and Civil Engineering, 2023
Mahmoud Hayek, Tara Soleimani, Marie Salgues, Jean-Claude Souche, Eric Garcia-Diaz
In addition to cement, the concrete industry uses a large amount of sand. Sand is the fine aggregate used in concrete manufacturing to ensure the granular continuity between the coarse aggregate and the cement (Zeghichi et al., 2014). Sand is generally obtained by extraction from land quarries or riverbeds. Because of the regulations and/or limited availability, the river deposit resources are becoming rare and expensive in some areas. On the other hand, crushing rocks to obtain the sandy fraction is difficult and requires high energy consumption (Kaufmann, 2020). In addition, sand is becoming scarce in some regions of the earth, and in some cases, the sand should be transported over long distances, which imposes negative economic and environmental impacts (Peduzzi, 2014). In contrast to the extensive SCM research, there is relatively limited experimental research on the feasibility of replacing crushed sand (CS) with an alternative material in concrete production. To date, two candidate materials have been mainly presented in the literature: dune sand and dredged marine sediments (DMS).
Evaluation of structural formation of granular materials using anisotropy of magnetic susceptibility
Published in Marine Georesources & Geotechnology, 2023
Xueqian Ni, Yupeng Cao, Feng Zhang, Zhao Zhang
To verify the feasibility of the AMS technique for investigating the orientation of granular materials, five types of clean sand were utilized in this study. The sand has different physical properties from different deposition environment, such as beach sand, river sand, aeolian sand, and calcareous sand. With respect to the results from the AMS technique, both the physical properties and the mineral composition will influence the testing data. Therefore, the basic information of each sand is given in the following part. To be specific, the particle size distribution curve was analyzed by sieve test, and the mineral composition pattern was obtained by X-ray diffraction (XRD) test.