Geotechnics

Representative

Description

The research carried out in this area of concentration covers practically all the activities of this specialty of Civil Engineering and includes laboratory and field experiments, as well as analytical and numerical studies. The main research topics are: slopes and containment systems, foundations and soil-structure interaction, field tests and instrumentation, earthworks, environmental geotechnics, sidewalks and soil stabilization, reinforced soils, soft soils, soil rheology and rock mechanics.

An important feature of the Geotechnics concentration area is its strong interaction with industry. In this sense, extension activities are carried out in all the areas mentioned above, through contracts and agreements with public bodies and companies. These include research and studies related to the stabilization and containment of earthy and rocky slopes in urban areas and on highways; walls reinforced with geosynthetics in the laboratory (physical models) and in the field; innovative constructive solutions for embankments on very soft soils in urban areas, ports and highways; specialized geotechnical investigations in the laboratory and in the field, with piezocone and vane equipment developed at COPPE; specialized monitoring of various works, including measurements of stresses in clamps and geosynthetic reinforcements; consultancy on works with special foundations; studies on pipelines and risers through centrifugal and numerical modelling; studies on unsaturated soils and erosion, laboratory and field studies on road and railway sidewalks; studies on soil contamination; studies on various types of waste (urban solids, dredging sediments, mining); bricks with a special technique using stabilized soil; innovative techniques for lining and covering waste landfills in general; studies on earth and rockfill dams, etc. As a result, the vast majority of the research carried out has had a direct influence on the practice of geotechnical engineering.

COPPE’s Geotechnics Laboratory occupies an area of around 2000m2, including the following sectors (laboratories): soil strength and deformability tests, field tests and instrumentation, sidewalks, bituminous mixtures, soil chemistry and minerology, environmental geotechnics, physical modeling (drum and arm centrifuge, 1G models and calibration chamber), solid waste and rock mechanics.

Lines of Research

Natural slopes subject to mass movement processes are the immediate objective of the course. Cutting slopes in engineering works, as well as erosion processes such as gullies, have been studied. Slope instrumentation is discussed. Analysis and design techniques for retaining structures in general are also investigated. Research involves reinforced soil walls and slopes, including natural soils (crushed soil) and embankments. Underwater slopes and canyons under seismic stress and underwater debris flows are also studied through physical modeling in a geotechnical centrifuge.

This line of research covers various topics such as: predicting the settlement of shallow foundations using semi-empirical methods; predicting the load capacity of deep foundations using theoretical and semi-empirical methods; the static and dynamic behavior of piles; the study of the effects of time (creep and relaxation) on foundations; the behavior of mixed foundations (associations between piles and footings or radiers); the tensile load capacity of piles; soil-structure interaction: study of combined structure-foundation behavior; behavior of open excavations and tunnels; structured embankments with geosynthetic platform.

In this line of research, laboratory and field investigation techniques in general are studied with the aim of determining the characteristics of earth and rock materials in general and their geotechnical parameters used in the analysis of deformations and stability of geotechnical works in general. The earthworks studied include dams in general and embankments and on soft soils, from design to performance evaluation through monitoring with geotechnical instrumentation. The studies include physical modeling in a geotechnical centrifuge and numerical modeling using finite elements.

Sidewalk mechanics applied to roads, airports, urban sidewalks and railway sidewalks. Constitutive modeling using the finite element method. Viscoelasticity theory. Fracture mechanics. Rheology applied to asphalt materials. Laboratory tests: (a) asphalt binders – traditional tests and the Superpave methodology; (b) soils and aggregates – resilience modulus, resistance to permanent deformation and MCT; (c) asphalt mixtures – resilience modulus, dynamic modulus, resistance to fatigue, permanent deformation and moisture damage. Mechanistic design methods – empirical. Sidewalk evaluation. Maintenance and rehabilitation design under performance criteria defined from stress-strain analysis. Retroanalysis of deflection basins. Recycling using rejuvenating agents and foamed bitumen. Physical chemistry of soils, Ki and Kr. Chemical stabilization of soils and the use of industrial waste for paving and the production of bricks for low-income housing.

Research into the relationship and impact of meteorological events and vegetation on mass movements on natural slopes; geotechnical works on contaminated land, forecasting and controlling the risks involved and potential impacts; the influence of different types of inorganic and organic contaminants on the geotechnical and hydraulic properties of soils; the mechanical behavior (strength and compressibility) of different types of waste (urban, dredging, mining and others); stabilization of waste and its use in geotechnical works (RCDs, dredging, ash and slag, dregs, treatment plant sludge, and others); innovative techniques for covering and lining waste in land or underwater disposal, including the use of geosynthetics; investigation of the long-term behaviour of waste deposits on land (landfills, dams, lakes, piles) from a geotechnical and environmental point of view; electrokinetic processes in soils and their relationship with the electrical, thermal, mechanical and hydraulic properties of soils.