A new indicator of elastic spectral shape for the reliable selection of ground motion records     

Mehdi Mousavi  Mohsen Ghafory‐Ashtiany  Alireza Azarbakht 《地震工程与结构动力学》2011,40(12):1403-1416

How to select a limited number of ground motion records (GMRs) is an important challenge for the non‐linear analysis of structures. Since epsilon (ε_Sa) is an indicator of spectral shape, which has a significant correlation with the non‐linear response of a structure, the selection of GMRs based on the hazard‐related target ε_Sa is a reasonable approach. In this paper, an alternative indicator of spectral shape is proposed, which results in a more reliable prediction of the non‐linear response for the structures with the natural period of 0.25 to 3.0 s. This new parameter, named eta (η), is a linear combination of ε_Sa and the peak ground velocity epsilon (ε_PGV). It is shown that η, as a non‐linear response predictor, is remarkably more efficient than the well‐known and convenient parameter ε_Sa. The influence of η‐filtration in the collapse analysis of an eight‐story reinforced concrete structure with special moment‐resisting frames was studied. Statistical analysis of the results confirmed that the difference between ε‐filtration and η‐filtration can be very significant at some hazard levels. In the case of this structure, the resulting annual frequency of collapse was found to be lower in the case of η‐based record selection, in comparison with the ε‐based record‐selection approach. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

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

Mohsen Abbaszadeh  Kourosh Shahriar  Mostafa Sharifzadeh  Mehrdad Heydari 《Geotechnical and Geological Engineering》2011,29(4):581-596

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.  相似文献   

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

Salah El Beialy  Maher El-Soughier  Sayed Abdel Mohsen  Haytham El Atfy 《Journal of African Earth Sciences》2011,59(2-3):215-226

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.  相似文献   

Using fuzzy TOPSIS method for mineral processing plant site selection     

Mohsen Safari  Reza Kakaei  Mohammad Ataei  Mohammad Karamoozian 《Arabian Journal of Geosciences》2011,5(5):1011-1019

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.  相似文献   

Building Information Modelling for High‐rise Land Administration          下载免费PDF全文

Behnam Atazadeh  Mohsen Kalantari  Abbas Rajabifard  Serene Ho  Tuan Ngo 《Transactions in GIS》2017,21(1):91-113

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.  相似文献   

Genesis of the Nasirabad manganese occurrence,Fars province,Iran: Geochemical evidences     

Alireza Zarasvandi  David Lentz  Mohsen Rezaei  Houshang Pourkaseb 《Chemie der Erde / Geochemistry》2013

The Nasirabad manganese occurrence is located to the south of the Neyriz in the Fars province. Structurally and lithologically, this occurrence lies in the southwest part of the Zagros Thrust Belt and was deposited as Mn-nodules and interconnected ore-bearing interlayer's with radiolarite cherts in the vicinity of the Neyriz ophiolites. The present work deals with the geology and geochemistry of the Nasirabad manganese occurrence with a discussion of its genesis. High Mn/Fe (average 18.85) and high Ba (average 28,830 ppm) with low Pb (2.0 ppm) and LREE > HREE, La_n/Nd_n (average 4.5), Dy_n/Yb_n (average 1.2) and negative Eu anomaly suggest distal hydrothermal source. The Co/Zn (average 2.2), Ce/La ratio (average 0.67) and trace element discrimination diagrams indicate hydrothermal–hydrogenous processes. Y/Ho ratio (average 24.85) and strong positive correlation coefficient between major oxides and some high field strength elements (HFSE) like; TiO₂ vs Fe₂O₃ (r = 0.98), Al₂O₃ vs Zr (r = 0.97), Al₂O₃ vs Fe₂O₃ (r = 0.98), Zr vs K₂O (r = 0.98), Nb vs TiO₂ (r = 0.92), Th vs Fe₂O₃ (r = 0.76), Th vs MgO (r = 0.86) reveal the presence of volcaniclastics and (or) terrigenous detritals of mafic composition being deposited into the depositional basin. It seems that intermittent interlayering of mafic detrital material derived from volcanic eruption of the Neyriz island arc directly affected the physicochemical conditions of hydrothermal ore precipitation in this basin and consequently the Nasirabad manganese ores represent hydrothermal–hydrogenous geochemical characteristics. The Nasirabad is an example of non-sulphidic, oxic Mn-mineralization. Similar trend between the enrichment and depletion of some bioessential elements (e.g., Mn, As, Ba, Sr, Co, Ce) might have been resulted from selective sequestering of metal ions by microbial processes and hence hydrogenous characteristics may also be the result of biogenetic processes. Moreover the high dilution of distal hydrothermal exhalations by sea water cannot be ruled out.  相似文献   

Release kinetics and distribution of boron in different fractions in some calcareous soils     

F. Ranjbar  M. Jalali 《Environmental Earth Sciences》2013,70(3):1169-1177

The aim of this study was to evaluate the release kinetics, speciation, and fractionation of boron (B) in some calcareous soils of western Iran. Ten surface soil samples were incubated with 100 mg B kg^?1 for a week at field capacity moisture. After air drying of samples, the trend of B release was experimented using sequential extraction with 10 mM CaCl₂. B speciation in soil solution was calculated for the first and the last steps of extraction by the visual MINTEQ program. The distribution of B among five fractions including exchangeable (F1), specially adsorbed (F2), bound by Fe–Mn oxides (F3), organically bound (F4) and residual (F5), was determined in control and spiked soils. The results indicated that the release rates were initially rapid followed by a slower reaction and the main proportion of the added B was extracted by CaCl₂. The release kinetics of B was described well with Elovich, parabolic diffusion, power function, and first-order equations. The speciation results revealed that the uncharged boric acid (H₃BO ₃ ⁰ ) was the dominant species in soil solutions. In control soils, B concentration in different fractions decreased in the following order: F5 > F1 > F2 > F3 > F4. In spiked soils, however, the largest and the smallest fractions were exchangeable and residual, respectively. This implies that B transformation from soluble to less mobile and non-labile forms is not a rapid process and requires more than a week. The significant relationship observed between kinetic parameters of power and parabolic equations and organically bound B fraction and OM content indicated that organic matter played an important role in B adsorption and release in calcareous soils.  相似文献   

Using chemical analysis and modeling to enhance the understanding of soil solution of some calcareous soils     

Mohsen Jalali 《Environmental Earth Sciences》2013,68(7):2041-2049

The chemistry of soil solutions can be altered by human activities, due to the intense agricultural and husbandry, leading to leaching of nutrients and subsequently elevating ground water levels. Multivariate statistical and inverse geochemical modeling techniques were used to determine the main factors controlling soil solution chemistry of calcareous soils. In this research, a total of 21 calcareous soils was characterized and assessed for soil solution using soil column. The major cations in the studied soil solutions were in the decreasing order as Ca²⁺ > Mg²⁺ > Na⁺ > K⁺. The anions were also arranged in decreasing order as HCO $ _{3}^{ - } $  > Cl $ ^{ - } $  > SO $ _{4}^{2 - } $  > NO $ _{3}^{ - } $ . Concentrations of NO $ _{3}^{ - } $ , P, and K⁺ in soil solutions were in the range of 6.8–307.5 mg l^?1 (mean 63.2 mg l^?1), 5.0–10.4 mg l^?1 (mean 5.9 mg l^?1), and 2.8–54.6 mg l^?1 (mean 11.3 mg l^?1), respectively. Results suggest that the concentration of P in the soil solutions could be primarily controlled by the solubility of dicalcium phosphate dihydrate and dicalcium phosphate. Interactions between soil properties and observed solubility of nutrients were described, and put into empirical multivariate formulations. Obtained equations contained electrical conductivity (EC) as a key factor in determining nutrients solubility. Inverse geochemical modeling of soil solution using PHREEQC indicates the dissolution of calcite, anhydrite, halite, CO₂ (g), N₂ (g), and hydroxyapatite, and precipitation of sulfur. Cation exchange between Ca²⁺, Mg²⁺, K⁺ and Na⁺ occurred with Mg²⁺ and K⁺ into the solution, and Ca²⁺ and Na⁺ out of the solution. Determination of soil solution will improve soil management in the area, and preventing groundwater deterioration.  相似文献   

Mapping of the soil texture using geostatistical method (a case study of the Shahrekord plain, central Iran)   总被引：1，自引：0，他引：1  

Yaser Safari  Isa Esfandiarpour Boroujeni  Ardavan Kamali  Mohammad Hassan Salehi  Mohsen Bagheri Bodaghabadi 《Arabian Journal of Geosciences》2013,6(9):3331-3339

Soil texture is a key variable that reflect a number of soil properties such as soil permeability, water holding capacity, nutrient storage and availability, and soil erosion. The main objective of this study was to produce the kriged maps of soils of the Shahrekord region, central Iran. One hundred four soil samples were collected on a 375-m² sampling grid from the depths of 0–30, 30–60, and 60–100 centimeter, and their particle sizes were determined using hydrometer method. The results showed a moderately spatial correlation in the soil particles among sampling soil layers and across the study area. Moreover, increasing clay and therewith observation of heavier soil textures is evident from surface to subsurface layers of the soils in the studied area due to rainfall and/or irrigation agriculture. These findings indicated that study of the soil texture variation with depth can be used as a clue for site-specific management and precision agriculture. Moreover, we suggest further analysis by using other data layers like topographical parameters, land use, parent material, soil erosion, and any other information which might influence the spatial distribution of soil texture.  相似文献   

The impact of acid rain on phosphorus leaching from a sandy loam calcareous soil of western Iran   总被引：1，自引：0，他引：1  

Mohsen Jalali  Elaheh Naderi 《Environmental Earth Sciences》2012,66(1):311-317

Simulated acidic precipitation (1:1 equivalent basis H₂SO₄:HNO₃) at pH values of 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 and 7.0 were conducted using column leaching to determine impacts of simulated acid rain on phosphorus (P) leaching from a calcareous sandy loam soil over a 40-day period. Soil columns were irrigated every day to make a total of 1,061 mm, equivalent to 3.5 years of rainfall (based on average annual rainfall). Leachates were collected and analyzed for anions and cations. There was significant nonlinear correlation between the amount of P leached and the simulated acid rain (R ² = 0.61). Losses of P from the pH 2.5 and 7.0 treatments were 1.23, and 1.32 mg kg⁻¹, respectively. The results showed that the amount of P leached from pH 4 (1.46 mg kg⁻¹) and 5 treatments (1.52 mg⁻¹ kg⁻¹) were significantly larger than other treatments. Linear equation adequately described leaching of P in different treatments. The slope (mg kg⁻¹ day⁻¹) in the linear equation was defined as the leaching rate and for the pH 2.5 was 0.0354, and 0.0382 and 0.0406 for pH 4.5 and 7.0, respectively. The geochemical code Visual MINTEQ was used to calculate saturation indices. Leaching of P in different treatments was controlled by rate-limited dissolution of hydroxyapatite, β-tricalcium phosphate and to some extent octacalcium phosphate. The results indicate that acid rain in calcareous sandy loam soils may pose a risk in terms of groundwater contamination with P.  相似文献