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The occurrence of lateritic soils with clayey texture, unsaturated, and with high porosity is common in Brazil. When subjected to an increase in moisture (loss of suction) in the more superficial layers, such soils end up altering their stress–strain behaviors, which are complex, culminating in countless geotechnical uncertainties. A phenomenon referred to as collapse is attributed to materials subjected to variation in saturation that entail significant differential settlements. Considering this situation, following the implementation of the Geotechnical Engineering Experimental Field located in the state of Rio Grande do Sul, Brazil, a broad study involving laboratory tests (granulometry, x-ray diffraction, water retention curve, confined compression, direct shear (natural and inundated condition), and consolidated drained triaxial compression tests) and field tests (SPT and static pile load tests) was carried out in the natural moisture and inundated conditions to assess the conditions of saturation and loss of suction in such materials. The results indicated that the shear strength of the soil was linked to the suction, having an 81.34% decrease in the cohesive intercept, and practically maintaining the soil friction angle. Confined compression tests with inundation indicated that the soil presented itself as potentially collapsible. The results obtained from the conducted pile load tests, revealing a substantial decline in carrying capacity ranging from 29 to 43% attributed to saturation of unsaturated soils, emphasize the paramount significance of this scientific article in comprehending the potential hazards associated with diminished bearing capacity and the subsequent emergence of structural pathologies or, in extreme cases, structural collapse. [ABSTRACT FROM AUTHOR]

Due to its impact, COVID-19 has been stressing the academy to search for curing, mitigating, or controlling it. It is believed that under-reporting is a relevant factor in determining the actual mortality rate and, if not considered, can cause significant misinformation. Therefore, this work aims to estimate the under-reporting of cases and deaths of COVID-19 in Brazilian states using data from the InfoGripe. InfoGripe targets notifications of Severe Acute Respiratory Infection (SARI). The methodology is based on the combination of data analytics (event detection methods) and time series modeling (inertia and novelty concepts) over hospitalized SARI cases. The estimate of real cases of the disease, called novelty, is calculated by comparing the difference in SARI cases in 2020 (after COVID-19) with the total expected cases in recent years (2016–2019). The expected cases are derived from a seasonal exponential moving average. The results show that under-reporting rates vary significantly between states and that there are no general patterns for states in the same region in Brazil. The states of Minas Gerais and Mato Grosso have the highest rates of under-reporting of cases. The rate of under-reporting of deaths is high in the Rio Grande do Sul and the Minas Gerais. This work can be highlighted for the combination of data analytics and time series modeling. Our calculation of under-reporting rates based on SARI is conservative and better characterized by deaths than for cases. [ABSTRACT FROM AUTHOR]

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Permeability is the ability of a sediment deposit to allow fluids to pass through it. It depends on the local types of sediments. When the fluid is oil, high permeability implies greater interaction with the site and more extensive damage, which makes recovery most difficult. Knowledge of permeability oscillations is necessary to understand oil behavior and improve cleanup techniques. The goal is to determine oil permeability variations on lagoon sand beaches. Oil permeability tests were performed at the beach face, using a Modified Phillip Dunne Permeameter and parameters were sampled. Permeability of lagoon beaches is driven by grain diameter and roundness, soil compaction, and depth of the water table. Factors that enhance permeability include: sand sorting, vertical distribution of sediments and gravel percentage. High permeability on lagoon beaches is related to polymodal distribution, to the sediment package, and to the system's low mobility. [ABSTRACT FROM AUTHOR]

The use of scrap tires in civil engineering involves creative solutions and diversified applications. The present paper presents parametric analyses based on laboratory data with different tires, wall heights, filling materials, water levels and soil friction angles. A design draft for 376 different earth retaining structures (combining all variables) was made and a statistical analysis performed to study the effect that each variable had on the base value. Finally, a case study is presented of a tire wall construction near Ijuí City - RS. The cost of this solution is given in comparison with the traditional concrete ones. [ABSTRACT FROM AUTHOR]

Permanent deformation is associated with wheel track rutting (WTR) and is one of the main causes of defects in the pavements of Brazilian highways. Seeking to mitigate this situation, this paper presents a study about the permanent deformation of three typical subgrade soils of the Santa Maria region, Rio Grande do Sul (RS), located in the southern region of Brazil. In addition to the physical, chemical, and mechanical characterization of the materials, this research presents results from repeated load triaxial tests to obtain the resilient modulus (RM) and the permanent deformation (PD) parameters. The Compound model of the resilient modulus, posteriorly cited on the Petrobras Asphalt Thematic Network Project, showed the best results. The permanent deformation tests were conducted using a frequency of 2 Hz and 150,000 load application cycles and posteriorly adjusted to the Guimarães Model, of which average statistical correlation was 0.91. However, the predominance of fine materials combined with low compaction energy resulted in high deformation rates and the occurrence of shakedown in domains: A (plastic shakedown), B (plastic creep) and C (incremental collapse). [ABSTRACT FROM AUTHOR]