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A laboratory study of stress arching around an inclusion due to pore pressure changes

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 678-693页

作者： hani Asaei Mahdi Moosavi Mohammad Ali Aghighi University of Tehran TehranIran

When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressure change in the region. The region may have the same or different elastic moduli with the surrounding rock, which is usually referred to as inclusion or inhomogeneity. Stress arching is responsible for many geomechanical problems encountered during production or injection; in addition, it is a crucial parameter in stress estimation during field development. This paper aims to present laboratory measurements of vertical stress arching ratio in a material surrounding the inclusion(inhomogeneity).To the authors’ knowledge, few laboratory experiments have been reported on direct measurement of stress arching. The inclusion is a cylindrical sandstone(44 mm in diameter and 50 mm in height)embedded in a larger cylindrical sandstone(150 mm in diameter and 154 mm in height), both of which are made synthetically. These two parts are separated and sealed by a internal polyurethane *** stress changes are recorded by a mini hydraulic sensor embedded in surrounding rock. Laboratory results are compared to those obtained by numerical models. These models are checked with analytical formulations. The results of numerical models show a good agreement with laboratory *** numerical results also indicate that the sensor response is affected by elastic properties of the internal sleeve. According to the sensitivity analysis performed, in the absence of the internal sleeve,properties of the inclusion have significant effects on the surrounding stress arching induced.

关键词： Stress arching Laboratory test Large-scale sample Synthetic sandstone

Numerical modeling of destress blasting for strata separation

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2238-2249页

作者： Petr Konicek Tuo Chen hani S.Mitri Institute of Geonics Czech Academy of SciencesOstrava70800Czech Republic Department of Mining and Materials Engineering McGill UniversityMontrealH3A 0E8Canada

Destress blasting(DB)implemented along the perimeter of safety pillars is a special application of destressing in coal longwall *** goal is to separate relatively more deformed mined areas from safety pillars,such as shaft pillars or cross-cut pillars,to reduce the transfer of high stresses to the protective *** case study aims to numerically simulate selected destress blasts in the Czech part of the Upper Silesian Coal Basin and examine its impact on stress transfer to the safety pillar *** separate the area between the protective pillar and the longwall(LW),two fans of five 93-mm blast holes(length of 93e100 m)were drilled from the gate roads into the overburden *** set of blast holes was fired separately in two stages without time *** explosive charge(gelatin-type of explosive)of each stage is 3450 *** two DB stages were fired when the longwall face was approximately 158 m and 152 m away from the blast.A 3D mine-wide model is built and validated with in situ stress measured with *** and destressing in three 5-m thick coal seams are simulated in the *** modeling of DB is successfully conducted using a rock fragmentation factor a of 0.05 and a stress reduction/dissipation factor β of *** of transfer of additional stress from the mining area into the safety pillar is evaluated by comparison of yielding volume before and after *** is shown that yielding volume drops after DB by nearly 80%in the area of the destressing panel and near the safety shaft pillar.

关键词： Rockburst hazard Destress blasting(DB) Strata separation Safety pillar Numerical modeling Fragmentation factor Stress dissipation factor Longwall mining

Volumetric analysis of rock mass instability around haulage drifts in underground mines

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 60-71页

作者： Shahé Shnorhokian Bryce MacNeil hani S.Mitri Department of Mining and Materials Engineering McGill University

Haulage networks are vital to underground mining operations as they constitute the arteries through which blasted ore is transported to surface. In the sublevel stoping method and its variations, haulage drifts are excavated in advance near the ore block that will be mined out. Numerical modeling is a technique that is frequently employed to assess the redistribution of mining-induced stresses, and to compare the impact of different stope sequence scenarios on haulage network stability. In this study,typical geological settings in the Canadian Shield were replicated in a numerical model with a steeplydipping tabular orebody striking EW. All other formations trended in the same direction except for two dykes on either side of the orebody with a WNW-ESE strike. Rock mass properties and in situ stress measurements from a case study mine were used to calibrate the model. Drifts and crosscuts were excavated in the footwall and two stope sequence scenarios-a diminishing pillar and a center-out one-were implemented in 24 mining stages. A combined volumetric-numerical analysis was conducted for two active levels by comparing the extent of unstable rock mass at each stage using shear,compressive, and tensile instability criteria. Comparisons were made between the orebody and the host rock, between the footwall and hanging wall, and between the two stope sequence scenarios. It was determined that in general, the center-out option provided a larger volume of instability with the shear criterion when compared to the diminishing pillar one(625,477 m~3 compared to 586,774 m~3 in the orebody; 588 m~3 compared to 403 m~3 in the host rock). However, the reverse was true for tensile(134,298 m~3 compared to 128,834 m~3 in the orebody; 91,347 m~3 compared to 67,655 m~3 in the host rock)instability where the diminishing pillar option had the more voluminous share.

关键词： Haulage drifts Rock mass instability Volumetric analysis Stope sequences Numerical modeling

Machine learning methods for rockburst prediction-state-of-the-art review

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International Journal of Mining Science and Technology 2019年第4期29卷 565-570页

作者： Yuanyuan Pu Derek B.Apel Victor Liu hani Mitri School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2R3Canada Department of Mining and Materials Engineering McGill UniversityMontreal H3A 2T6Canada

One of the most serious mining disasters in underground mines is rockburst *** can lead to injuries and even fatalities as well as damage to underground openings and mining *** has forced many researchers to investigate alternative methods to predict the potential for rockburst ***,due to the highly complex relation between geological,mechanical and geometric parameters of the mining environment,the traditional mechanics-based prediction methods do not always yield precise *** the emergence of machine learning methods,a breakthrough in the prediction of rockburst occurrence has become possible in recent *** paper presents a state-ofthe-art review of various applications of machine learning methods for the prediction of rockburst ***,existing rockburst prediction methods are introduced,and the limitations of such methods are highlighted.A brief overview of typical machine learning methods and their main features as predictive tools is then *** current applications of machine learning models in rockburst prediction are surveyed,with related mechanisms,technical details and performance analysis.

关键词： Rockburst prediction Burst liability Artificial neural network Support vector machine Deep learning

Using Portable Gamma-Ray Spectrometry for Testing Uranium Migration: A Case Study from the Wadi El Kareim Alkaline Volcanics,Central Eastern Desert, Egypt

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Acta Geologica Sinica(English Edition) 2018年第6期92卷 2214-2232页

作者： Osama K. DESSOUKY hani H. ALI Nuclear Materials Authority P.O.Box 530El MaadiCairoEgypt

The 300±20 Ma anomalously radioactive trachytes of Wadi El Kareim, central Eastern Desert, are a significant example of U-mineralization related to the alkaline volcanics in Egypt. Extensive portable gamma-ray spectrometric data has been utilized to identify geological factors controlling uranium mobility in the geological units along the three detailed study locations of Kab Al-Abyad, South Wadi(W) Al-Tarafawy and W. Al-Farkhah; their eT h/eU ratios averaging around 4.1, 3.7 and 5.6 respectively. Quantitative analysis with the integration of mobility maps and geological studies suggest two systems controlling U-migration within the geological units(confined system and unconfined system). In the confined system, the syngenetically formed U have experienced mobility after leaching and are redistributed in the presence of an incorporation carrier during transportation(probably as carbonate complexes). Then the retardant for uranium is achieved by sorption or by coprecipitation with the aid of Fe oxy-hydroxide, and finally the formation of immobile secondary U-bearing minerals takes place along a lithogeochemical trap. In contrast to the confined system, the unconfined one is basically lacking the lithogeochemical trap which influences the final accumulation of U-bearing minerals. The radioactivity of the trachyte rocks arises from the radioactive minerals uranophane and betauranophane with U-and/or Th-bearing minerals samarskite, Th-rich REE silicates, monazite and allanite.

关键词： radioactivity uranium migration systems alkaline volcanics Egypt

Data-Fusion for Epidemiological Analysis of Covid-19 Variants in UAE

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Computers, Materials & Continua 2021年第9期68卷 3895-3913页

作者： Anoud Bani-hani Anaïs Lavorel Newel Bessadet Zayed University DubaiUnited Arab Emirates Staffordshire University Stoke-on-TrentST42DEUnited Kingdom Keele University NewcastleST55BGUnited Kingdom

Since December 2019,a new pandemic has appeared causing a considerable negative global *** SARS-CoV-2 first emerged from China and transformed to a global pandemic within a short *** virus was further observed to be spreading rapidly and mutating at a fast pace,with over 5,775 distinct variations of the virus observed globally(at the time of submitting this paper).Extensive research has been ongoing worldwide in order to get a better understanding of its behaviour,influence and more importantly,ways for reducing its *** analytics has been playing a pivotal role in this research to obtain valuable insights into understanding and fighting against the spread of ***,this is time and resource intensive,making it difficult to observe and quickly identify the impact of *** such as the spread or virulence could explain the three months delay in revealing the new virus variant in the *** paper presents an extensive correlation analysis of the effect caused by the different SARS-CoV-2 strains,and their influence on the population across diverse factors,such as propagation and fatality rates,during the peak of the pandemic,with a focus on two major countries in the Middle East,the United Arab Emirate(UAE)and the Kingdom of Saudi Arabia(KSA).This research aims to investigate the epidemiological behaviour of the Coronavirus’genomic variants over time in the UAE,compared with the KSA,where correlation analysis is carried out for a number of cases,deaths and their statistical *** results of the analysis highlight very interesting insights into the epidemiological impact of the Covid-19 genomic behaviour in both countries,which could lead to important actions taken to minimize the impact on wider public health,possibly saving lives,and the *** instance,our method identifies a potential correlation between a spike in the number of deaths per case of 5.5 observed in the UAE by March 24th,with the emergence of new

关键词： SARS-CoV-2 genome covid-19 public health pandemic epidemiology case study United Arab Emirates UAE Kingdom of Saudi Arabia KSA

Ibuprofen-Induced Toxic Epidermal Necrolysis:A Case Report

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International Journal of Dermatology and Venereology 2024年第2期7卷 108-110页

作者： Nevin Kannappilly Mohamed Z.Peediyakkal Mohamad Y.Khatib Dore C.Ananthegowda Moustafa S.Elshafei hani El Zeer Karimulla S.Shaik Moayad M.AlFayoumi Dyaneshwar P.Mutkule Ahmed A.Soliman Abdulqadir J.Nashwan Critical Care Department Hamad Medical Corporation(HMC)Doha 3050Qatar

Introduction:Toxic epidermal necrolysis(TEN)is a medical emergency that most commonly occurs as an adverse effect of certain ***,we describe a case of a 41-year-old man with no comorbid illness who developed *** presentation:The patient had been prescribed ibuprofen for myalgia and developed skin lesions after the single *** lesions were erythematous papules and macules distributed all over the body after ibuprofen *** was diagnosed based on the patient’s clinical presentation and laboratory *** was treated with intravenous dexamethasone,intravenous immunoglobulin,and *** dressing changes and skin care was done with saline,chlorhexidine,and liquid *** patient was intubated and tracheostomized,and he gradually improved and ***,he developed septicemia in the intensive care unit and was treated ***:The management of TEN includes cessation of the causative cause,multidisciplinary intensive care unit(ICU)care,prevention and early detection of sepsis,fluid and electrolyte balance,adequate analgesia and temperature control,proper organ support,aggressive nutritional management,and good psychological *** pharmacological therapy for TEN includes corticosteroids,intravenous immunoglobulin,and *** key elements of management are aseptic care and proper dressing of the ***:TEN is associated with high mortality if not managed in a systemic and protocolized way.

关键词： ibuprofen toxic epidermal necrolysis erythema drug-induced erythema

Numerical modelling of spatially and temporally distributed on‑fault induced seismicity:implication for seismic hazards

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International Journal of Coal Science & Technology 2023年第1期10卷 108-123页

作者： Atsushi Sainoki Adam Karl Schwartzkopf Lishuai Jiang hani Mitri Faculty of Advanced Science and Technology KumamotoUniversityKumamotoJapan School of Engineering The University of Western AustraliaPerthAustralia State Key Laboratory of Mining Disaster Preventionand Control Shandong University of Scienceand TechnologyShandongChina Department of Mining and Materials Engineering McGillUniversityMontrealCanada

Induced seismicity is strongly related to various engineering projects that cause anthropogenic in-situ stress change at a great ***,there is a need to estimate and mitigate the associated *** the past,various simulation methods have been developed and applied to induced seismicity analysis,but there is still a fundamental diference between simulation results and feld observations in terms of the spatial distribution of seismic events and its *** present study aims to develop a method to simulate spatially distributed on-fault seismicity whilst reproducing a complex stress state in the fault ***,an equivalent continuum model is constructed,based on a discrete fracture network within a fault damage zone,by employing the crack tensor theory.A fault core is simulated at the center of the model as a discontinuous *** the model,a heterogeneous stress state with stress anomalies in the fault zone is frst simulated by applying tractions on the model outer ***,the efective normal stress on the fault plane is decreased in a stepwise manner to induce *** simulation result is validated in terms of the b-value and other seismic source parameters,hence demonstrating that the model can reproduce spatially and temporally distributed on-fault *** analysis on the parameters shows the variation of frequency-magnitude distribution before the occurrence of large seismic *** variation is found to be consistent with feld observations,thus suggesting the potential use of this simulation method in evaluating the risk for seismic hazards in various engineering projects.

关键词： Induced seismicity Fracture network Fault damage zone Crack tensor theory

Analysis of particulate behavior in porous media

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Applied Mathematics and Mechanics(English Edition) 2008年第4期29卷 511-516页

作者： hani I.Siyyam M.H.Hamdan Department of Mathematics and Physics College of Arts and SciencesQatar UniversityP.O.Box 2713DohaQatar Department of Mathematical Sciences University of New BrunswickP.O.Box 5050Saint JohnNew BrunswickCanada

In this work, we analyze the behavior of the particle phase in the flow of a particle-laden mixture through a porous medium. An attempt is made to model the diffusion and dispersion processes, and to quantify the devi... 详细信息

关键词： porous media dusty gases particle behavior