Resumen en Inglés:

Abstract Soil-atmosphere interactions comprise a multidisciplinary and transdisciplinary subject of interest to numerous applied and research knowledge areas. In this work, aspects related to geotechnical, geoenvironmental and geological engineering, not usually considered in applied civil or environmental engineering projects, are put forward, exemplifying the role that micro-climatic conditions may have in the development of gravitational soil mass movements such as erosion processes and natural slope stability comprising unsaturated tropical soils. Based on literature data, proposals are put forward to consider cracks that develop under dry climatic conditions in engineering projects. Additionally, laboratory testing results indicate that the shear strength of soils may decrease due to climatic dry-wetting cycles, potentially compromising the accuracy of slope stability analysis results. In addition, the need to evaluate initial soil-water profile conditions in flow analysis is presented and discussed under various scenarios, and the effects of further atmospheric events, such as lightning, are also presented and discussed. Furthermore, based on data collected from diverse Brazilian sanitary landfills designed to operate primarily on municipal solid waste, relationships between soil-atmospheric variables and biogas generation and emission are investigated. Finally, based on the results generated in a physical model, a type of final municipal landfill cover is presented and discussed, whose design strongly depends on atmospheric data.

Resumen en Inglés:

Abstract This paper, in commemoration of 75 years of the Brazilian Society for Soil Mechanics and Geotechnical Engineering, highlights contributions of Brazilian Geotechnicians to some selected topics of Environmental Geotechnics, i.e., design of municipal solid waste landfills, tropical soils and alternative clay liners, and remediation, and also brings forward the production of new geomaterials by means of an example of an engineered clay developed in Belgium with enhanced performance in barriers systems. The overall Brazilian expertise in geoenvironmental research, practice and design extends to many other geoenvironmental topics that were not presented and deserve another publication. Nonetheless, based on the given examples, the paper shows the essential role of Geotechnics in the well-being of the populations and in the fight against deterioration of the planet, and that challenges are continuously in progress for environmental Geotechnicians.

Resumen en Inglés:

Abstract Argentinean loessial soils are the main deposits of this kind of soil in South America, and cover an area of more than 600,000 km2. They are eolic soils that can preserve their original structure generated when they were deposited (primary loess) or being transported or altered in place (secondary loess or loessoid). Recent deposits are mainly primary, ML and CL-ML, whereas the older ones are similar to other unsaturated clayed and silty soils, CL and CH. Geotechnical behavior varies from collapsing soils, for primary loess, to overconsolidated by desiccation for the secondary loessoid deposits. Advances have been made in the knowledge of the cementation processes, the dielectric properties and the mechanical variations with different levels of strains, in the use of new nondestructive methods, in-situ tests and spatial variations of the most significant parameters. It has been progressed in the modeling of foundations and different infiltration processes. The engineering design is conditioned by the type of collapsibility. The criteria used in constructions try to annul the entrance of water into the ground; to eliminate the collapsibility by means of the improvement of its unstable structure or to avoid using direct foundations. In hydraulic works predominates the use of the hydro-compaction combined with methods to accelerate the collapse. Loessic soils are apt for using in embankments and fillings, because compaction destroys their macroporous structure and they behave like other types of silty soils. In order to clarify the engineering problems and its solution two history cases are explained.

Resumen en Inglés:

Abstract The integration of advanced digital technologies is revolutionizing transportation geotechnics, enabling unprecedented achievements in efficiency of design, construction and maintenance contributing to more sustainable infrastructure developments. This paper explores cutting-edge advancements in self-sensing geomaterials, stiffness characterization using bender elements in unbound geomaterials, remote sensing, bridge scour detection and building information modelling (BIM), showcasing their transformative potential. Self-sensing geomaterials embedded with nanomaterials act as sensors provide real-time stress, strain and loading monitoring, enhancing health structural monitoring. Stiffness characterization is upscaled from sand to unbound aggregates through the application of bender element testing. Remote sensing technologies, including InSAR, enable slope stability assessments across networks, while AI-powered predictive models improve landslide risk mitigation, as well as network-scale bridge scour detection. The paper also highlights the BIM’s contribution to infrastructure sustainable practices through the use of recycled construction and demolition wastes (RCDWs).

Resumen en Inglés:

Abstract This article presents the advances in geosynthetic engineering in Brazil in the last 50 years. The topics addressed encompass soil-geosynthetic interaction, reinforced embankments on soft soils, drainage and filtration, the use of vertical drains to accelerate settlements, geosynthetic-encased granular columns for soft soil improvement, structured embankments on soft soils, reinforced walls and geosynthetics in mining. The research activities employed laboratory tests, full-scale field tests, laboratory and geotechnical centrifuge tests on physical models, monitoring of projects and numerical modelling. Several of these academic studies were carried out with the support and cooperation of the geosynthetic industry and have had an important impact on constructive practices, enabling geosynthetic engineering in Brazil to reach the high level of competence and maturity that has been evident in recent years.

Resumen en Inglés:

Abstract Brazilian geotechnics plays a key role in the pursuit of safer and environmentally sustainable tailings disposal solutions. From that perspective, this paper outlines the Brazilian academia and industry contributions to the geotechnics of mining tailings, highlighting the main aspects of some recent studies carried out by Brazilian research groups. Firstly, a literature review focusing on Brazilian research, published mainly in the last decade, is first presented. Subsequently, aspects relating to the behavior of tailings dams are discussed, including statistical methods for accurately assessing strength parameters, static liquefaction susceptibility of tailings subjected to various stress paths, and numerical models used to evaluate the effect of triggers on the onset of liquefaction of upstream tailings dams. Finally, regarding filtered tailings stacks, increasingly viewed as a preferable option for tailings storage, topics related to particle breakage, transitional behavior, effects of undercompacted materials and static liquefaction susceptibility of iron and rare earth tailings are addressed.

Resumen en Inglés:

Abstract Brazilian experience in the design and execution of foundations to support superstructures of distinct sorts goes way back to the early colonial period of the XVI century, a few years after the discovery of this land (Katinsky, 1994). Since then, the geotechnical technology related to such constructions has been considerably upgraded and expanded to new system types. The present manuscript aims to briefly review some key aspects of the foundation practice in Brazil during its last decades of development, from the mid-20th century to the present daytime. It does not intend to make a state-of-the-art of the subject but rather highlights the most interesting and relevant points in this evolutionary process of design and construction techniques. Prospective or future foundation technologies will also be envisaged. Given space limitations, it will definitively be narrowed, absent or eventually unfair in some topics or comments. Still, it will serve to highlight the importance of this particular field in the context of the special celebration issue of the 75 years of the Brazilian Soil Mechanics Association. It has been collectively written by some of the most experienced and renowned practitioners and researchers of the Brazilian geotechnical society, despite the absence of so many high-quality others that could equally be present herein. Time and space, unfortunately, have deprived this manuscript of a broader participation and scope.

Resumen en Inglés:

Abstract This article presents a speculative exercise aimed at anticipating future developments in rock mechanics, both in its application areas and in research. To frame this discussion within the historical evolution of the field, it seemed relevant to first provide a brief retrospective on the emergence of rock mechanics in the post-war years as a distinct discipline within geotechnical engineering, as well as on its key developments from then to the present. The article identifies application domains where significant advancements are expected, not only within traditional areas, such as civil, mining, and petroleum engineering, but also in areas that have gained importance over time, as well as in emerging application domains. Research in rock mechanics will face new challenges driven by society’s demand for safer, more cost-effective, and more sustainable solutions. It must also adapt to, and benefit from, the challenges presented by new applications, the rapid development of communication and digital technologies, and the expanding role of artificial intelligence.

Resumen en Inglés:

Abstract Unsaturated soils mechanics (USM) and unsaturated soils technology (UST) have been the subject of great interest to Brazilian researchers and practitioners since the inception of the Brazilian Association for Soil Mechanics and Geotechnical Engineering (ABMS). This is in great part due to the geotechnical challenges involving swelling and collapsible soils commonly found in the country and issues related to landslide risk assessment and management. Progressively, problems associated with civil infrastructure, transportation geotechnics, environmental geotechnics, and engineered mine tailings disposal systems have also drawn the attention of professionals dealing with unsaturated soils. This paper celebrates the 75th anniversary of ABMS by presenting a summary of some of the main advances produced by Brazilian academia and geotechnical practitioners, in the field of USM and UST. Fundamentals of unsaturated soil are discussed, in the context of some typical Brazilian soils, including issues regarding soil microstructure, soil-water retention, and unsaturated shear strength. Brazilian developments in terms of swelling and collapsible soil identification, testing, and modeling are explored. Finally, geotechnical and geoenvironmental applications are discussed, focusing on the main issues investigated in the past four decades.

Resumen en Inglés:

Abstract Gravitational mass movements are recurring phenomena in Brazil, causing significant environmental impacts as well as human, social, and economic losses. Data on gravitational mass movement occurrences between 1988 and 2022 recorded 959 events in 16 Brazilian states, resulting in a total of 4,146 victims. Extreme rainfall events in recent years, particularly in Santa Catarina, Rio de Janeiro, Bahia, Minas Gerais, Pernambuco, São Paulo, and Rio Grande do Sul, suggest an increase in consequences due to climate change. Considering this scenario, this article analyzes case studies in states such as Pernambuco, Rio de Janeiro, São Paulo, Paraná, and Rio Grande do Sul, addressing causes, impacts, rupture mechanisms, and adopted solutions. Geological-geotechnical investigations, numerical analyses, and continuous monitoring have been crucial in understanding rupture mechanisms and proposing mitigating solutions. The studies identified geological and geomorphological conditions as the main predisposing factors, while inadequate human actions, insufficient investigation in infrastructure projects, and rainwater infiltration were found to be the primary aggravating and triggering factors. Therefore, with the increased frequency of extreme rainfall, it is essential to adopt new approaches that consider the impacts of these events in urban occupation and infrastructure projects, reinforcing preventive and adaptive strategies to reduce future risks.