Uncertainty and Reliability Analysis Applied to Slope Stability: A Case Study From Sungun Copper Mine

Nowadays, there are many new methods for slope stability analysis; including probabilistic methods assessing geotechnical uncertainties to develop safety factors. In this paper, a reliability index analysis for the Sungun copper mine slope stability is evaluated based on three methods of uncertainties consisting Taylor series method, Rosenblueth point estimate method and Monte-Carlo simulation method. Sungun copper mine will be one of the Iran’s biggest mines with final pit’s height of 700 meters. For this study two of its main slopes were assessed, one dipping to the NE (030) and the other to the SE (140). Probability density function of cohesion and angle of friction for the slopes were developed using limit equilibrium methods. These shear strengths were then used to determine the probability density function of safety factor and reliability index using the probabilistic methods. Results of the probabilistic analysis indicate that with ascending values of the uncertainties the reliability index decreases. Furthermore, it was determined that with the Monte Carlo simulation the seed number used has little effect on the reliability index of the safety factor especially with seed numbers in excess of 1200. Variations in the overall reliability index of safety factor were observed between the two slopes and this difference is explained by the differences in complexities of the geology within the cross-section.     

Using fuzzy TOPSIS method for mineral processing plant site selection

Site selection for the mineral processing is the most important decision made by owner that has a significant impact on the efficiency of the whole process. This is a critical decision which involves considering a number of criteria and finding the best location among feasible alternatives. Therefore, a multicriteria decision-making method is necessary to apply site-selection process to find the best location that meet desired conditions set by the selection criteria. This paper presents an application of TOPSIS method based on fuzzy sets (fuzzy TOPSIS), which is one of the broader multicriteria decision making means, used to select an appropriate site for mineral processing plant for Sangan iron ore mine (phase 2). For this purpose, at first considering the geological, technical, economical, and environmental factors, three feasible alternatives were selected for the processing plant using Geographical Information System. Then, based on the technical and experimental experiences and through judgment of the decision makers and experts, 14 criteria were established and these alternatives were evaluated. Finally, the alternatives were ranked and the best location was recommended.     

Palynostratigraphy and paleoenvironmental significance of the Cretaceous succession in the Gebel Rissu-1 well,north Western Desert,Egypt

Palynological investigation of the Cretaceous Abu Roash, Bahariya, Kharita, Alamein, Alam El Bueib and Betty formations, encountered in the Gebel Rissu-1 well, north Western Desert, Egypt yielded 27 species of pteridophytic spores, 24 of gymnosperm pollen, 25 of angiosperm pollen and 11 of dinoflagellate cysts in addition to some acritarchs, foraminiferal test linings and freshwater algae. This enabled us to recognize five miospore biozones arranged from youngest to oldest as: Classopollis brasiliensis–Afropollis cf. kahramanensis–Dichastopollenites ghazalataensis Assemblage Zone (Late Cenomanian); Elaterosporites klaszii–Sofrepites legouxae–Afropollis jardinus Assemblage Zone (Middle/Late Albian–Early Cenomanian); Pennipollis peroreticulatus–Duplexisporites generalis-Tricolpates Assemblage Zone (Early Aptian–Early Albian); Tucanopollis crisopolensis–Afropollis sp. Assemblage Zone (Barremian) and Appendicisporites cf. tricornitatus–Ephedripites spp. Assemblage Zone (Late Neocomian).The Early Cretaceous Kharita, Alam El Bueib and the Betty formations encountered in the Gebel Rissu-1 well are interpreted to indicate oxic proximal and distal shelf deposits, characterized by type III/IV, V kerogen, which is gas prone but having little potential to produce hydrocarbons. The Upper Cretaceous Abu Roash and Bahariya formations are characterized by a distal suboxic–anoxic and marginal dysoxic–anoxic environment, and their kerogen type III/II indicates gas/oil prone nature. The Bahariya and Kharita Albian–Cenomanian sediments in the present study witnessed the onset of a semi-arid to arid climate, with local or seasonal humid conditions, based on the continuous high abundance of the elaterates pollen and Afropollis-producing plants that inhabited the paleotropical humid coastal plains.     

Site dependence and record selection schemes for building fragility and regional loss assessment

When performing loss assessment of a geographically dispersed building portfolio, the response or loss (fragility or vulnerability) function of any given archetype building is typically considered to be a consistent property of the building itself. On the other hand, recent advances in record selection have shown that the seismic response of a structure is, in general, dependent on the nature of the hazard at the site of interest. This apparent contradiction begs the question: Are building fragility and vulnerability functions independent of site, and if not, what can be done to avoid having to reassess them for each site of interest? In the following, we show that there is a non‐negligible influence of the site, the degree of which depends on the intensity measure adopted for assessment. Employing a single‐period (e.g., first‐mode), spectral acceleration would require careful record selection at each site and result to significant site‐to‐site variability of the fragility or vulnerability function. On the other hand, an intensity measure comprising the geometric mean of multiple spectral accelerations considerably reduces such variability. In tandem with a conditional spectrum record selection that accounts for multiple sites, it can offer a viable approach for incorporating the effect of site dependence into fragility and vulnerability estimates. Copyright © 2017 John Wiley & Sons, Ltd.     

Advances in techniques to formulate the watertight concept for cadastre

The world’s rising urban density expansion has resulted in a proliferation of attempts to efficiently use space and a higher level of spatial complexity in metropolitan areas. 3D geospatial data models are increasingly being embraced to facilitate communicating the spatial dimensions of complex built environments in different applications. For example, the use of 3D models in land administration systems has been recognized as a good approach for communicating the spatial complexity of legal spaces within multi‐storey buildings. The spatial extent of legal space—to which rights, restrictions and responsibilities relate in a 3D digital cadastre—needs to be accurately defined and geometrically closed; watertight. Therefore, this study aims to address the challenges regarding checking the closure of diverse 3D legal spaces and engage several techniques to formulate the watertight concept for cadastre. The research’s methodology is built on a 3D polyhedral surface using a half‐edge data structure. A primitive check is employed to assess the spatial consistency of lower‐dimensional primitives of 3D objects. Subsequently, advanced closure checks ensure the closure of volumetric legal spaces represented by 2‐manifold and non‐2‐manifold data models. The article concludes that, by adopting the proposed approaches, the internal spatial consistency of legal spaces in urban land administration will be certified.     

Hydrochemical Characteristics and Sodification of Groundwater in the Shirin Sou, Hamedan, Western Iran

Salinity and sodicity of groundwater are the principal water quality concerns in irrigated areas of arid and semi-arid regions. The hydrochemical characteristics and sodicity of groundwater in the Shirin Sou area, western Iran were investigated in this study by chemical analyses of groundwater samples from 49 wells. Chemical analysis of the groundwater showed that the mean concentration of the cations was in the order: Na⁺ > Ca²⁺ > Mg²⁺ > K⁺, while that for anions was SO₃ ²⁻ > Cl⁻ > HCO₃ ⁻ > NO₃ ⁻. The most prevalent water type is Na–SO₄ followed by water types Na–Cl and Ca–SO₄. The chemical evolution of groundwater is primarily controlled by water–rock interactions: mainly weathering of aluminosilicates, dissolution of sulfate minerals, and cation exchange reactions. Sulfate dissolution and pyrite weathering may both contribute to the SO₄ ²⁻ load of the groundwater. High Na⁺ concentrations in groundwater participate in ion-exchange processes, resulting in the displacement of base cations into solution and raised concentrations in groundwater. The principal component analysis (PCA) performed on groundwater identified three principal components controlling variability of groundwater chemistry. Electrical conductivity, Ca²⁺, Mg²⁺, Na⁺, SO₄ ²⁻, and Cl⁻ content were associated in the same component (PC1) (salinity), most likely linked to anthropogenic activities.     

Extent of diagenetic transformations in severely altered biogenic silica deposits from Tunisia: new insights from mineralogy and geochemistry

Sedimentary biogenic silica from Redeyef in Gafsa basin (southern Tunisia) was analysed for its ²⁹Si and ²⁷Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra and complemented by X-ray diffraction and SEM observations. The ²⁹Si MAS NMR spectrum is characterized by the abundance of hydroxylated silicon, displayed in resonance intensities and reflects a clear tendency towards dissolution of diatomaceous amorphous silica and the occurrence of the hydrated silica, which is the main component that ensures the diagenetic transition via the mechanism of dissolution–precipitation to other more crystalline silica phases, after the lost of its hydroxyls groups (water) by heating (burial). ²⁷Al MAS NMR reveals two coordinations of Al; the octahedrally coordinated Al suggests the presence of clay relics trapped during crystal growth or a microcrystalline zeolite (clinoptilolite detected by SEM observations), while the tetrahedrally coordinated Al suggests the presence of minor quantities of minerals with tetrahedral Al, such as an Al-rich fluid and/or minerals such as feldspars.     

Building Information Modelling for High‐rise Land Administration

Current land administration systems mainly use 2D plans to define and secure ownership rights associated with properties in high‐rise buildings. These 2D plans may not effectively communicate and manage the spatial complexity associated with multi‐layered and stacked properties in such buildings; additionally, multiple pages of plans (representing sections of the building) are required to represent all ownership boundaries. In response, land administration organizations have been investigating a 3D digital approach to managing information about ownership rights in high‐rise building structures. In this article, Building Information Modeling (BIM) is proposed as a feasible approach for managing land and property information in high‐rise buildings. BIM provides a collaborative, digital and intelligent 3D data environment for managing building information throughout the lifecycle of buildings. However, there is currently no capacity in BIM for recording and representing information about ownership and boundaries of properties, which is core land administration information. Therefore, this article proposes an extension to the BIM standard, which is implemented in a prototype BIM model of a complex building to showcase the potential capability of using BIM for high‐rise land administration and for modeling 3D ownership rights.