block-flexure is the most common mode of toppling failure in natural and excavated rock slopes. in such failure, some rock blocks break due to tensile stresses and some overturn under their own weights and then all of them topple together. in this paper, first, a brief review of previous studies on toppling failures is presented. then, the physical and mechanical properties of experimental mode...

The build-up of carbon dioxide (CO2) and other greenhouse gases in the Earth’s atmosphere has caused concern about possible global climate change. As a result, international negotiations have produced the Framework Convention on Climate Change (FCCC), completed during the 1992 Earth Summit in Rio de Janeiro. The treaty, which the United States has ratified, calls for the “stabilization of green...

We revisit the case for the hyperthermophilic scenario for the origin of life and the last common ancestor. Evidence includes studies of phylogenetic trees, rRNA, G and C content, hyperthermophilic proteins, correlations between maximal temperature tolerances and genetic distances, saline stabilization of DNA/RNA, and the inferred climatic temperatures of the early Earth. Although some doubts r...

The conventional method to evaluate earthquake induced permanent deformations of slopes is the one proposed by Newmark. In this paper, permanent displacement of slopes is studied using a combination of distinct element and finite difference methods and the results of these numerical evaluations are compared with those of the Newmark's approach. Several parameters involved, including peak ground...

We study here slopes of periodicity of tilings. A tiling is of slope θ if it is periodic along direction θ but has no other direction of periodicity. We characterize in this paper the set of slopes we can achieve with tilings, and prove they coincide with recursively enumerable sets of rationals.

Stability of reinforced slopes is almost always carried out using limit equilibrium methods and controlled by the shear strengths of the slope materials and the extension force of reinforcements. According to limit equilibrium methods, the stability of slopes is assessed by dividing the whole failure wedge into several vertical elements. In order to determine the safety factor of the reinforce...

Introduction: Embankments are constructed in many places for transportation purposes such as railways and roads. The stability of slopes embankments has always been a concern, especially cohesionless soils. There methods to increase the safety factor soil using geogrids, geocells, concrete piles, so on. conventional material used stabilize huge impact on environment. Nowadays, researchers natur...

The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tre...