Visual illusions in geology
Examples of visual illusions in the laboratory are well documented, but what about illusions that occur during field observation of geological structures? In this article I discuss a study involving geologists and non-geologists and define some of the problems that may arise during geological field and laboratory work.
Summary of "Concerning some additional aids in studying sedimentary formations," by M. S. Shvetsov
An article by the Russian sedimentologist, Shvetsov, is summarized for wider distribution among Western geologists. The summary includes reproduction of Shvetsov's diagrams for visual estimation of percentages of minerals in rock sections. In addition, the article points out the usefulness of water and acid for visual study of rock sections.
On the use of the Hardening Soil Small Strain model in geotechnical practice
This article highlights the importance of using advanced constitutive soil models in numerical modelling as daily geotechnical practice. In this context, the Hardening Soil (HS) model is presented as the most advanced soil model implemented in the ZSoil finite element code. The article recalls the basic features of the HS model and it explains their role in numerical simulations. The role of pre-failure non-linear behaviour of soils is also discussed. An application of the HS model is illustrated on typical geotechnical problems such as retaining wall excavation, tunnel excavation and undrained loading followed by consolidation.