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Evaluation of the effect of geometrical parameters on stope probability of failure in the open stoping method using numerical modeling

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International Journal of Mining Science and Technology 2019年第3期29卷 399-408页

作者： Shahriyar Heidarzadeh ali saeidi Alain Rouleau Department of Applied Sciences University of Quebec at Chicoutimi

Stress-induced failure is among the most common causes of instability in Canadian deep underground *** stoping is the most widely practiced underground excavation method in these mines,and creates large stopes which are subjected to stress-induced *** probability of failure(POF)depends on many factors,of which the geometry of an open stope is especially *** this study,a methodology is proposed to assess the effect of stope geometrical parameters on the POF,using numerical *** ranges for each input parameter are defined according to previous surveys on open stope geometry in a number of Canadian underground mines.A Monte-Carlo simulation technique is combined with the finite difference code FLAC3D,to generate model realizations containing stopes with different geometrical *** probability of failure(POF)for different categories of stope geometry,is calculated by considering two modes of failure;relaxation-related gravity driven(tensile)failure and rock mass brittle *** individual and interactive effects of stope geometrical parameters on the POF,are analyzed using a general multi-level factorial ***,mathematical optimization techniques are employed to estimate the most stable stope conditions,by determining the optimal ranges for each stope’s geometrical parameter.

关键词： Stope stability Stope geometrical parameters Probability of failure General factorial design Numerical modeling Sublevel open stoping

Determination of uncertainties of geomechanical parameters of metamorphic rocks using petrographic analyses

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 345-364页

作者： Behzad Dastjerdy ali saeidi Shahriyar Heidarzadeh Department of Applied Sciences University of Quebec at ChicoutimiSaguenayQCCanada SNC-Lavalin MontrealCanada

Geomechanical parameters of intact metamorphic rocks determined from laboratory testing remain highly uncertain because of the great intrinsic variability associated with the degrees of *** aim of this paper is to develop a proper methodology to analyze the uncertainties of geomechanical characteristics by focusing on three domains,*** treatment process,schistosity angle,and ***,the variabilities of the geomechanical laboratory data of Westwood Mine(Quebec,Canada)were examined statistically by applying different data treatment techniques,through which the most suitable outlier methods were selected for each parameter using multiple decision-making criteria and engineering *** indicated that some methods exhibited better performance in identifying the possible outliers,although several others were unsuccessful because of their limitation in large sample *** well-known boxplot method might not be the best outlier method for most geomechanical parameters because its calculated confidence range was not acceptable according to engineering ***,several approaches,including adjusted boxplot,2MADe,and 2SD,worked very well in the detection of true ***,the statistical tests indicate that the best-fitting probability distribution function for geomechanical intact parameters might not be the normal distribution,unlike what is assumed in most geomechanical ***,the negative effects of schistosity angle on the uniaxial compressive strength(UCS)variabilities were reduced by excluding the samples within a specific angle range where the UCS data present the highest ***,a petrographic analysis was conducted to assess the associated uncertainties such that a logical link was found between the dispersion and the variabilities of hard and soft minerals.

关键词： Intact rock parameters Natural variabilities Outlier detection methods Uncertainties Westwood mine Mineralogy

A method to determine relevant geomechanical parameters for evaluating the hydraulic erodibility of rock

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 1004-1018页

作者： Lamine Boumaiza ali saeidi Marco Quirion Département des Sciences appliquées Universitédu QuébecàChicoutimiChicoutimiG7H 2B1Canada Expertise en barrages Direction Barrages et infrastructuresHydro-QuébecMontréalH2Z 1A4Canada

Among the methods used for evaluating the potential hydraulic erodibility of rock,the most common methods are those based on the correlation between the force of flowing water and the capacity of a rock to resist erosion,such as Annandale’s and Pells’*** capacity of a rock to resist erosion is evaluated based on erodibility indices that are determined from specific geomechanical parameters of a rock *** indices include unconfined compressive strength(UCS)of rock,rock block size,joint shear strength,a block’s shape and orientation relative to the direction of flow,joint openings,and the nature of the surface to be potentially ***,it is difficult to determine the relevant geomechanical parameters for evaluating the hydraulic erodibility of *** assessment of eroded unlined spillways of dams has shown that the capacity of a rock to resist erosion is not accurately *** more than 100 case studies,we develop a method to determine the relevant geomechanical parameters for evaluating the hydraulic erodibility of rock in unlined *** UCS of rock is found not to be a relevant parameter for evaluating the hydraulic erodibility of *** the other hand,we find that the use of three-dimensional(3D)block volume measurements,instead of the block size factor used in Annandale’s method,improves the rock block size ***,the parameter representing the effect of a rock block’s shape and orientation relative to the direction of flow,as considered in Pells’method,is more accurate than the parameter adopted by Annandale’s method.

关键词： Rock mass Hydraulic erodibility Geomechanical parameters Rock block size Annandale’s method Pells’method Kirsten’s index Erosion level

Determining relative block structure rating for rock erodibility evaluation in the case of non-orthogonal joint sets

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 72-87页

作者： Lamine Boumaiza ali saeidi Marco Quirion Department of Applied Saences University of Quebec at Chicoutimi Hydro-Quebec

The most commonly used method for assessing the hydraulic erodibility of rock is Annandale's *** method is based on a correlation between the erosive force of flowing water and the capacity of rock resistance. This capacity is evaluated using Kirsten's index, which was initially developed to evaluate the excavatability of earth materials. For rocky material, this index is determined according to certain geomechanical factors related to intact rock and rock mass, such as compressive strength of intact rock, rock block size, discontinuity shear strength and relative block structure. To quantify the relative block structure, Kirsten(1982) developed a mathematical expression that accounts for the shape and orientation of the blocks relative to the direction of flow. Kirsten's initial concept for assessing the relative block structure considers that the geological formation is mainly fractured by two joint sets forming an orthogonally fractured system. An adjusted concept is proposed to determine the relative block structure when the fractured system is non-orthogonal where the angle between the planes of the two joint sets is greater or less than 90°. An analysis of the proposed relative block structure rating shows that considering a non-orthogonally fractured system has a significant effect on Kirsten's index and, as a consequence, on the assessment of the hydraulic erodibility of rock.

关键词： Fractured rock Dip angle Dip direction Joint spacing Relative block structure Hydraulic erodibility of rock Annandale’s method Kirsten’s index

Rockburst in underground excavations:A review of mechanism,classification,and prediction methods

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Underground Space 2022年第4期7卷 577-607页

作者： Mahdi Askaripour ali saeidi Alain Rouleau Patrick Mercier-Langevin Department of Applied Sciences University of Quebec at ChicoutimiChicoutimi G7H 2B1Canada Geological Survey of Canada Quebec CityQC G1K 9A9Canada

Technical challenges have always been part of underground mining activities,however,some of these challenges grow in complexity as mining occurs in deeper and deeper *** such challenge is rock mass stability and the risk of rockburst *** overcome these challenges,and to limit the risks and impacts of events such as rockbursts,advanced solutions must be developed and best practices *** are common in underground mines and substantially threaten the safety of personnel and equipment,and can cause major disruptions in mine development and *** consist of violent wall rock failures associated with high energy rock projections in response to the instantaneous stress release in rock mass under high strain ***,it is necessary to develop a good understanding of the conditions and mechanisms leading to a rockburst,and to improve risk assessment *** capacity to properly estimate the risks of rockburst occurrence is essential in underground ***,a limited number of studies have examined and compared yet different empirical methods of *** current understanding of this important hazard in the mining industry is summarized in this paper to provide the necessary perspective or tools to best assess the risks of rockburst occurrence in deep *** various classifications of rockbursts and their mechanisms are *** paper also reviews the current empirical methods of rockburst prediction,which are mostly dependent on geomechanical parameters of the rock such as uniaxial compressive strength of the rock,as well as its tensile strength and elasticity *** the end of this paper,some current achievements and limitations of empirical methods are discussed.

关键词： Rockburst Empirical methods Underground instability Rockburst prediction methods

Modelling of the variation of granular base materials resilient modulus with material characteristics and humidity conditions

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Journal of Road Engineering 2024年第1期4卷 27-35页

作者： Jean-Pascal Bilodeau Erdrick Leandro Perez-Gonzalez ali saeidi Departement de Genie Civil et Genie des Eaux Universite LavalQuebecG1V 0A6Canada Departement des Sciences Appliquees Universite du Quebeca ChicoutimiChicoutimiG7H 2B1Canada

This study aims to quantify the susceptibility of granular materials used in pavements to changes in moisture content and propose a correlation model to incorporate this susceptibility into seasonal *** fines content and the percentage of fractured coarse aggregates were identified as direct indicators of the resilient modulus susceptibility to changes in water *** results showed that the percentage of fractured coarse aggregates particles(FR)has a more significant impact on the resilient modulus(Er)of crushed granular materials used in pavement construction than the combined indicator of the fines content and sample volumetrics(nf).Crushed granular materials with a higher percentage of fractured coarse aggregates are relatively insensitive to changes in the degree of saturation,but become more sensitive as the fine fraction porosity *** adjusted model was proposed based on the existing formulation,but considers a complex parameter to describe and adjust the sensitivity of base granular materials to variations in moisture content with respect to fabrication charac-teristics,fines content and volumetric *** model shows that the variation of Er values is below10%for fully crushed granular ***,it reaches approximately±12%for materials with 75%of crushed coarse aggregates andþ40%and-25%for materials with FR=50%.This model could help select good ag-gregates characteristics and adjust grain-size distribution for environments where significant moisture content variations can occur in the pavement system,such as in the Province of Quebec(Canada).As it is based on pa-rameters that can be easily determined or estimated,it also represents a valuable tool for detailed design and analysis that can consider material characteristics.

关键词： Resilient modulus Degree of saturation Humidity conditions Unbound granular materials Pavement base

Iran supports a great share of biodiversity and floristic endemism for Fritillaria spp.(Liliaceae)：A review

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Plant Diversity 2017年第5期39卷 245-262页

作者： Mahmoud Kiani Shirin Mohammadi alireza Babaei Fatemeh Sefidkon Mohamad Reza Naghavi Mojtaba Ranjbar Seyed ali Razavi Keramatollah saeidi Hadi Jafari Davoud Asgari Daniel Potter Department of Biotechnology & Medicinal Plants Amol University of Special Modem Technologies Amol Iran Department of Horticultural Science Shiraz University Shiraz lran Department of Horticultural Sdence Tarbiat Modares Umverslty lenran lrand Research Institute of Forests and Rangelands Tehran lrane Department of Agronomy and Plant Breeding Faculty of Agriculture University of Tehran Karaj lran Department of Horticulture Faculty of Agriculture Shahre Kord University Shahre Kord lrang Department of Physiology & Breeding of Ornamental Plants Engineering Faculty of Horticulture Sciences University of Tehran Karaj Iranh Department of Plant Sciences University of California-Davis Davis USA

Iran supports a great share of exotic and/or endemic plant genera and species. The genus Fritillaria(Liliaceae) is a precious part of this botanical richness with 19 species, of which 10 are endemic to the country. However, signs are mounting that the country is truly at a crossroads when it comes to preservation of this national wealth. In this regard, an effective conservation strategy should thoroughly consider the classification of Fritillaria, as conservation practices are compromised by knowledge gaps in systematics and taxonomy. As published studies on Fritillaria in Iran have been sporadic and limited in scope, the aim of this review is to provide information necessary to help bridge these information *** objective is to facilitate increased understanding of the geographic, taxonomic, cytogenetic and phylogenetic status of Iranian Fritilloria, which is vital to meeting the goal of sustainable conservation of the genus in Iran and neighboring areas.

关键词： Conservation Ecosystem Endemic Phylogenetic Middle East Taxonomy

A Novel Method to Identify the Global Sources and Sinks of Carbon Dioxide Based on Spatial Analysis

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Journal of Geographic Information System 2015年第2期7卷 110-118页

作者： ali Madad Babak Naimi saeidi Anjileh Mehdi Department of Environment and Energy Faculty of Science and Research Branch of Islamic Azad University Tehran Iran Department of GIS/SDI National Cartography Center of Iran Tehran Iran

Today global warming has become one of the most important concerns of environmental science. The redundancy of greenhouse gases in the atmosphere is known as a major factor in this phenomenon. These gases contain water vapor, carbon dioxide, methane, nitrous oxide, and ozone. The CO2?gas is one of their most effective among these gases. According to scientific warnings, the amount of CO2?gases in the atmosphere has increased by 40% to 45% over the last 50 years. Reducing the abundant gas in the atmosphere requires a good knowledge of related factors involved, including sources that emit gases into the atmosphere and sinks that absorb the gas from the atmosphere. The amount of CO2?gas in the atmosphere has been accurately measured in previous years with great certainty. But the predicted values of emissions from sources and removals by sinks have large ambiguities. As studies show, even the computed residuals trends (which is obtained by subtracting the amounts of sinks from sources) strongly disagree with the trends of the existence of CO2?in the atmosphere. This study as a preliminary review, proposes a method to identify the locations of sources and sinks of carbon dioxide using global statistical information and adding spatial analysis approaches. By applying this method to the data observed from 2000 to 2011 and the extraction of likely sources and sinks, the region of the Black Sea, near Romania recognized as one of the strong points issued and Bukit Kototabang near Indonesia acknowledged as an Impressive CO2?absorption zone.

关键词： Carbon Dioxide Sink Spatial Autocorrelation Interpolation Volcanic Shape

How to Implement a Governmental Open Source Geoportal

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Journal of Geographic Information System 2014年第4期6卷 275-285页

作者： saeidi Anjileh Mehdi Madad ali Ghasemlou Nima Rezaie Zahra saeidi Reyhaneh Baktash Peyman Department of GIS/SDI National Cartography Center of Iran Tehran Iran

By emerging the OGC web services technologies which caused server interoperability in geospatial fields, a rush toward implementing geoweb services commenced among most governmental enterprises. The massive geospatial information which has been produced in various offices during previous years, and which was not available for public customers because of protocol difficulties, now had a chance to be restructured as OGC specifications and be reachable to huge amount of keen clients via Internet platform. Increasing number of map presenters in web environment raised a search facility requirement in spatial data area. These kinds of search abilities are called “Geoportal”, which provides client applications that use several geo services such as catalogs and web map services. How to implement a suitable geoportal to meet the needs, has brought a set of hard challenges for governmental geospatial owners. In this study we present an overall concept of service oriented architecture and its consequence web service specifications and eventually web catalog services which are fundamentals of developing a geoportal. It also declares some experiments on importing/exporting data between geoportals, which is known as harvesting method.

关键词： Catalog Services GIS Portal Geo Network Catalog Harvesting Interoperability