Georg R Sadowski

To optimize the prediction of structural geological conditions in the underground as of data collected at the surface, due to the usual great uncertainties involved, we discuss new perspectives for the construction of structural geological models, bearing in mind the common doubts involved and their implications in the safety of infrastructure works, mining, etc. This paper presents a statistical simulation applied to structural geological measures (dip-dip direction) obtained from schists during the design and construction of civil works through a correlation between surface data with different depth levels. Angular structural geological measures of joints and foliations converted in direction cosines were subjected to the PERMANOVA test to verify the amplitude of differences at different depth levels. The asymptotic results allowed to determine regions of confidence built around centroids through statistical simulation, allowable consistency was considered in regions where the dif...

Large subhorizontal joints have been found in the foundation excavations in basalt and granite of Brazilian Dams. Some spread for hundreds of square meters showed slickensides—polished surfaces plus striations—and laminations interpreted as related to shear displacement, what substantially reduced their shear strength and imposed special reinforcement measures against the potential sliding of overlying concrete structures. The geological characteristics of these discontinuities have raised speculations related to their origin, be it related to mechanisms of bulging, cambering or to some tectonic or primary geological event. Several geologists and engineers from the northern hemisphere including Terzaghi already showed to be concerned with their role in granite foundations while in the southern regions Brazilian authors have found similar occurrences but also affecting individual lava flows of continental flood basalts in the foundations of major dams of the Parana Basin, which they designated under the particular name of “fault-joints”. This double-standard designation is self-explanatory of the difficulties involving their origin and related geomechanical properties: faults or just shear joints? Recently, similar features were encountered in the foundations of large dam constructions in anorogenic granites inserted in the realm of the Brazilian Amazon, where some of these discontinuities exhibit features common to tectonic thrusting combined with deep tropical weathering. The evidence of preshearing along the surfaces of such fractures, also associated to products of deep weathering, reduces their geomechanical strength substantially, suggesting values of ultimate phi spanning 12 to 28°. The detection of these descontinuities during initial investigation phases continues to be a major complex task in geological risk evaluations surveys. Trenching associated to some geophysical exploration techniques, although considered to be very basic exploration techniques are still the suggested methods for their forecast and previous determination.

Entablatures, colonnades and “fault-joints” have been found in many excavations of dam foundations, tunnels and quarries in basaltic rocks of southern Brazil, but frequently they were not formally identified as such, and the two first, only rarely. This lack of recognition led many times to misunderstanding of their importance to slope stability and foundation problems. This short note reviews their basic definitions and stresses the influence of their properly consideration in the development of geotechnical projects.

We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces. 1 Introduction. Tectonic plate construction of the earth lithosphere is generally accepted and well described at the present (for example, see [1, 3]). Moreover, the tectonic plates of another planets of the solar system as Mars and Venus are a subject of investigations, as well ([2]). The tectonic plate motion as

One may think that geological affiliation and environmental conditions of formations are the main hint to understand the mechanical properties of the rocks. It is expected that the input of highly energetic pressure–temperature (PT) conditions should impose the formation of harder rocks in relation to those related to the origin of soft rocks. Although reasonable, this is not a general rule since exceptions are found specially during the formation of chemical sedimentary rocks and by cementation effects by silica/iron rich oxides that may turn soft sands into very hard rocks. However, the transformation of hard rocks into soft is imposed by the inverse physical–chemical equilibrium conditions to which high PT minerals are easily transformed through weathering or when subjected to hydration under lower conditions of pressure and temperature (retro metamorphism, for example). So harder rocks may be transformed into sot rocks or “altered” rocks. For practical reasons soft rocks which a...

We suggest a model that describes a mutual dynamics of tectonic plates. It is a sort of stick-slip dynamics modeled by a Markov random process. The process defines the dynamics on a micro-level. A macro-level is obtained by a scaling limit which leads to a system of integrodifferential equations which determines a kind of mean field systems. The conditions when the Gutenberg-Richter empirical law holds are presented at the mean field level. Those conditions are rather universal and independent of the features of the resistant forces.

Entablatures, collonades and "fault -joints" have been found in many excavations of dam foundations, tunnels and quarries in basaltic rocks of southern Brazil, but frequently they were not identified as such, and the twofirst, only rarely. The lack of recognition led many times to misunderstanding of their importance to slope stability and foundation problems.This short note reviews their basic definitions and stresses the influence of their properlyconsideration in the development of geotechnical projects.

RESUMO Neste trabalho foi efetuado estudo petrográfico e geoquímico visando o estabelecimento do paleoambiente tectônico de rochas metabásicas encontradas na região do Alto e Médio Vale do Ribeira, entre as cidades de Apiaí. Iporanga e Barra do Turvo no ...

RESUMO Neste trabalho foi efetuado estudo petrográfico e geoquímico visando o estabelecimento do paleoambiente tectônico de rochas metabásicas encontradas na região do Alto e Médio Vale do Ribeira, entre as cidades de Apiaí. Iporanga e Barra do Turvo no ...

We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

On the limits of the Pernambuco and Paraiba States, Brazil, occurs a quartz syenitic body with an outcrop area of about 400 km2. At its East side lies a probably 'relative granite and both are apparently intruded in sc4ists of the Cachoeirinha and Uaua Groups. The area, loca- ...

... 3. Location and stratigraphy. 3.1. Location. Corumbella werneri Hahn et al. (1982) was first reported from the Claudia limestone quarry, owned by the Itaú Cement Company, in Corumbá–Ladário, Mato Grosso do Sul, southwestern Brazil (Fig. 3). Hahn et al. ...