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search filter All ContentAll ProceedingsAmerican Rock Mechanics AssociationU.S. Rock Mechanics/Geomechanics Symposium
VISIT ARMA
Proceedings Papers (33)
Casing and Cementing (2)
Casing design (2)
Completion Installation and Operations (2)
Perforating (1)
Completion Operations (1)
Drilling Operations (4)
Directional drilling (1)
Drilling operation management (2)
Naturally occurring radioactive materials (1)
Hydraulic Fracturing (2)
Improved and Enhanced Recovery (1)
Thermal methods (1)
Information Management and Systems (10)
Pressure Management (1)
Well control (1)
Professionalism, Training, and Education (1)
Communities of practice (1)
Research and Development and Emerging Technology Programs (1)
Reserves Evaluation (2)
Probabilistic methods (2)
Reservoir Characterization (21)
Exploration, development, structural geology (5)
Faults and fracture characterization (1)
Reservoir geomechanics (11)
Seismic processing and interpretation (2)
Reservoir Fluid Dynamics (1)
Flow in porous media (1)
Risk Management and Decision-Making (1)
Sand Control (1)
Strategic Planning and Management (1)
Well & Reservoir Surveillance and Monitoring (2)
Production logging (2)
Wellbore Design (6)
Rock properties (2)
Wellbore integrity (3)
Keywords: liner
How the Design Criteria for Slotted Liners in SAGD are Affected by Stress Buildup Around the Liner
M. Roostaei, Y. Guo, A. Velayati, A. Nouri, V. Fattahpour, M. Mahmoudi
Publisher: American Rock Mechanics Association
Paper presented at the 52nd U.S. Rock Mechanics/Geomechanics Symposium, June 17–20, 2018
Paper Number: ARMA-2018-642
... ABSTRACT: Unconsolidated sand was packed on a slotted-liner coupon in large-scale sand retention tests (SRT) and was subjected to several stress conditions, corresponding to the evolving stress conditions during the life cycle of a SAGD producer. Cumulative produced sand at the end of testing...
ABSTRACT: Unconsolidated sand was packed on a slotted-liner coupon in large-scale sand retention tests (SRT) and was subjected to several stress conditions, corresponding to the evolving stress conditions during the life cycle of a SAGD producer. Cumulative produced sand at the end of testing was measured as the indicator for sand control performance. Retained permeability was calculated by measuring pressure drops near the liner and was considered as the quantification of the flow performance of the liner. Experimental results indicate the liner performance is significantly affected by the stress induced compaction of the oil sand. The stress results in the sand compaction, leading to a denser sand, hence, a lower porosity and permeability. The lower porosity results in a higher pore-scale flow velocity, which can trigger more fines mobilization, hence, a higher skin buildup. With respect to sanding, the higher stress can stabilize the sand bridges: Increased normal forces between near-slot sand particles result in a higher inter-particle friction, hence, more stable sand bridges and less produced sand. The lower and upper bounds of slot window are governed by plugging and sand production, respectively. Experimental results indicate an upward shift in both the lower and upper bounds at elevated stress conditions
3D Finite Element Analysis and Experimental Study of Stability of Slotted Liners
X. Liu, N. Morita
... ABSTRACT: The goal of the study is to find the optimal design of slotted liners by 3D finite element analysis and experimental study. Slotted liners are widely used in horizontal wells because of the abilities to ensure wellbore integrity and sand control. During installation and operations...
ABSTRACT: The goal of the study is to find the optimal design of slotted liners by 3D finite element analysis and experimental study. Slotted liners are widely used in horizontal wells because of the abilities to ensure wellbore integrity and sand control. During installation and operations, the slotted liners have to be strong enough to hold axial loads and radial compression to prevent excessive buckling and deformation of slots. Experiments were designed to select the grades of materials, diameter/thickness of pipes, slot pattern. Finite element models were developed to decide the slotted liner design under various load conditions. The study showed considerations for slotted liner design and analyzed how much material grades, casing/tubing dimension and slot patterns can be expected to evaluate the risk of slotted liner failure.
A Proposed Probabilistic Analysis Methodology for Tunnel Support Cost Estimation Depending on the Construction Method
A. Mitelman, D. Elmo
... TBM tunnel support cost estimation criteria deviation Reservoir Characterization Upstream Oil & Gas PoF assessment ground condition risk management reserves evaluation liner cost estimation construction method iteration probabilistic analysis methodology tunnel support class...
ABSTRACT: The extent of support in tunneling projects can vary greatly depending on the geological conditions, and in turn may greatly affect project costs. For the purpose of project pre-feasibility assessment, methodologies are proposed according to the tunnel construction method, conventional tunneling (NATM), or mechanized tunneling (TBM). For both cases, statistical analysis tools in conjunction with stress and strain calculations are used in order to assess the volume of tunnel support. It is suggested that for TBM tunnels, the Probability of Failure is adopted as a failure criterion, and the volume of support computed accordingly. For NATM tunnels, a fixed Factor of Safety should be used in order to predict the support distribution and resultant support volume. A practical example is presented, for the comparison of support cost and construction schedule estimation of the two excavation methods, for a tunnel to be excavated through weak rock. 1. INTRODUCTION Perhaps the greatest challenge in underground engineering is dealing with the inherent uncertainty that stems from the heterogeneous nature of geological formations. In tunneling and underground caverns, the strength characteristics of the ground, whether rock or soil, dictate the support required for stabilization. Studies have shown that the extent of support has a significant impact on the overall project budget (Paraskevopoulou and Benardos, 2012). Naturally, the degree of uncertainty is greatest at the prefeasibility stage. Decision makers must determine whether to carry out a project, or to choose between different construction alternatives, based on very limited data. Considering the high cost and risks of underground projects, it is essential that reliable analysis tools are made available. Currently, studies have shown that cost over-runs in tunnel projects are a global phenomenon. For example, Efron and Read (2012) examined 158 tunnel projects from 35 countries, and concluded that in every case the final cost was higher than the initial estimation.
Isothermal Creep Behaviour Investigation of Thin Spray-on Liners
D. Guner, H. Ozturk
Paper presented at the 51st U.S. Rock Mechanics/Geomechanics Symposium, June 25–28, 2017
Paper Number: ARMA-2017-0320
... ABSTRACT: Rock supporting has a vital importance in longevity and sustainability of all underground openings. There are many types and forms of supporting systems available in the mining/tunneling industry. In the last decade, a new polymer-based surface support material, thin spray-on liner...
ABSTRACT: Rock supporting has a vital importance in longevity and sustainability of all underground openings. There are many types and forms of supporting systems available in the mining/tunneling industry. In the last decade, a new polymer-based surface support material, thin spray-on liner (TSL), has started to take place of conventional surface support materials. TSL is defined as generally cement, latex, polymer-based and also reactive or non-reactive, multi-component materials applied to the rock surface with a layer of few millimeter thickness. They have the advantages of low volume, rapid application and low operating cost. The majority of current TSLs are two-part polyurethane/polyuria or Portland cement based latex products that are mixed on site before spraying onto surfaces. They are now being considered for highly stressed, deep, rock bursting conditions as a reinforcement and retaining element together with bolts and screen. In this study, the creep behavior of a cement-based TSL was investigated. For this purpose, 7-day cured dogbone TSL specimens were tested under 23±2°C laboratory conditions. A range of dead weights (80, 60, 40, and 20 % of the tensile strength) were applied until the rupture of the specimens. As a result of this study, the time-dependent strain behavior of a TSL was presented for different constant load conditions. Moreover, a new equation was derived to estimate tensile failure time of the TSL for a given loading condition. If the tensile stress acting on the TSL is known, the effective permanent support time of the TSL can be estimated by the proposed relationship. 1. INTRODUCTION
Modeling of Key Lifespan Stages of a Pre-Salt Wellbore
P. A. L. P. Firme, R. J. Quevedo, D. Roehl
.... INTRODUCTION Wellbore Design liner Reservoir Characterization lifespan wellbore integrity poiate jr Upstream Oil & Gas cement channel failure ratio internal pressure application salt rock borehole wall Rio de Janeiro full evacuation period overlap evacuation period cement sheath...
ABSTRACT: Oil and gas wellbores experience a number of phases and scenarios during their lifespan. Drilling, completion, production and abandonment imply significant changes in the mechanical behavior of the well and its surrounding rock formation. Stress state and temperature changes are even more significant in Pre-salt wellbores since the creep behavior inherent to the salt rocks is strongly influenced by these state variables. This work presents a comprehensive Pre-salt wellbore integrity analysis addressing key phases of the well lifespan. Preventing casing from plastic deformations is recommended. The analyses were carried out with an in-house finite element simulator, GeoFlux3D, and have highlighted the wellbore casing sensitivity to the internal pressure and to the channels in the cement sheath. Plastic deformation has not been detected; however, the full evacuation periods and the cement channel affect negatively the casing integrity by triggering severe stress changes and non-uniformities, respectively. Therefore, proper definition of the loading and geometry scenarios to which Pre-salt wellbores are subjected is fundamental for reliable integrity predictions. 1. INTRODUCTION
Influence of Embankment Loading on the Hydro-Mechanical Response of a NATM Tunnel in Saturated Ground
S. H. Prassetyo, M. Gutierrez
Paper presented at the 50th U.S. Rock Mechanics/Geomechanics Symposium, June 26–29, 2016
... changes, but also hydraulic response through pore pressure changes. Because this hydro-mechanical (H-M) response will be transferred to the tunnel liner and because the liner deforms with the ground, the embankment load will correspondingly influence the liner's stability. This paper examines how severely...
Abstract: Tunnel design in urban areas must account for overburden loads as well as additional loads imposed by future surface infrastructures, called the embankment load. In saturated ground, the embankment load will generate not only mechanical response through stress and displacement changes, but also hydraulic response through pore pressure changes. Because this hydro-mechanical (H-M) response will be transferred to the tunnel liner and because the liner deforms with the ground, the embankment load will correspondingly influence the liner's stability. This paper examines how severely the induced H-M response from the embankment load will affect the integrity of a horseshoe-shaped (NATM) tunnel in saturated ground. Two tunnel models are created in the computer code FLAC. One model is under weak and low-permeability ground (i.e., clay), and the other one is under relatively strong and high-permeability ground (i.e., granite). Each tunnel model is run under different liner drainage conditions: permeable and impermeable. The embankment load is then applied 10 years after tunnel construction. Simulation results suggest that impermeable tunnels will experience the most severe bending moment from the embankment load, particularly for tunnels in clay. Further, the severity does not stop shortly after the load is applied, but continues towards the steady-state. Introduction One of the geotechnical issues associated with tunneling in urban areas is excavation-induced deformation which, if not carefully controlled, may cause damage to existing surface structures. While this effect of tunneling has been a major environmental issue and widely studied for decades, research on the reverse situation – the influence of surface structures on an existing tunnel – has been limited. Nevertheless, the extra deadweight from future surface infrastructures, called the embankment load, should be addressed for tunnel design because it can affect the structural integrity of the tunnel. In dry ground, the embankment load will change the stress and displacement fields of the ground beneath the structure until equilibrium is reached. In urban tunneling, where the overburden is shallow, changes in the stress and displacement in the ground will easily generate additional ground pressure and structural forces on and in the liner, respectively, i.e., increasing the liner axial forces and bending moment (Rezaei et al., 2013; Katebi et al., 2015). Further, embankment loads have also been seen to widen settlement troughs, such as those found above the metro tunnels in London and Frankfurt (Potts & Addenbrooke, 1997).
New Performance Criterion for Thin Spray-on Liners: Tensile Toughness
... surface support systems [5, 6, 8, 12, 13, 15, 17] metals & mining strength liner thin spray-on liner performance criterion liner 3 Wellbore Design criterion tensile toughness Reservoir Characterization toughness value tensile modulus shotcrete TSL support system ultimate...
Abstract: Introduction Fast curing rate and ability to reach adequate mechanical properties in few hours after application [1, 2, 3] Discardable rebound amount and wastage during spraying process [2, 4, 5] Wide displacement range (elongation ratio) [6, 7, 8, 9, 10] Ease of application and fast application rate [2, 6, 8, 11, 12] Smaller spraying equipment [6, 13, 14] Less material handling with respect to other ground support products [6, 15, 16, 17] Decrease in the operating costs [4, 5, 6, 11] Thinner thicknesses of applied material with respect to other surface support systems [5, 6, 8, 12, 13, 15, 17]
Structural Design of Tunnel Supports by Combining a Point Estimate Method with a Deterministic Numerical Analysis Code (FLAC2D)
D. Park, E. S. Park
Paper presented at the 49th U.S. Rock Mechanics/Geomechanics Symposium, June 28–July 1, 2015
... moments of the performance functions related to the lined-tunnel. Additionally, we applied the present approach to the structural design of a steel liner which is installed in a pressurized tunnel for storing compressed natural gas at a pressure of 15 MPa. In this application, we investigated...
Abstract The objective of this study is to propose an alternative way for the probabilistic structural design of tunnel supports in combination with a deterministic numerical analysis code, FLAC2D. We proposed an approach for linking a point estimate method to the FLAC2D solver and developed a software program, called TunnelRA, which facilitates the probabilistic reliability assessment of tunnel supports. The validity of the present approach was investigated based on a lined-circular tunnel problem with an analytical solution and was demonstrated in the accurate estimation of the statistical moments of the performance functions related to the lined-tunnel. Additionally, we applied the present approach to the structural design of a steel liner which is installed in a pressurized tunnel for storing compressed natural gas at a pressure of 15 MPa. In this application, we investigated the probability of failure for the steel liner by varying the liner's strength and thickness, and provided information for decision making in structural design. The results of the present work demonstrated that the present numerical approach could be used for designing tunnel supports and for making relevant decisions in a quantitative manner. 1. INTRODUCTION Most of geotechnical parameters, such as the mechanical properties of soils and rocks, are uncertain. The uncertainties should be properly taken into account in geotechnical and structural designs. Probabilistic approaches are more useful in dealing with the uncertainties than conventional deterministic approaches in which the geotechnical parameters are conservatively assigned as single-fixed values determined by a designer's engineering judgment. Probabilistic approaches quantify the geotechnical uncertainties by statistical probability distributions. As a result, the reliability of structures can be quantitatively assessed in terms of the probability of failure in a limit-state. Regarding the probabilistic analysis of tunnel supports, there have been several researches such as Laso et al. [1], Li & Low [2], and Oreste [3]. For the probabilistic stability evaluation of tunnel supports, Laso et al. [1] and Li & Low [2] used a ground-support interaction diagram for a circular excavated tunnel for which analytical solutions are available, but it is not possible to apply their approaches to non-circular tunnels. Oreste [3] suggested a probabilistic approach for the reliability assessment of tunnel supports by using a hyperstatic reaction method. However, as indicated in his study, the hyperstatic reaction method has such limitations that the active loads which are applied to tunnel supports should be exactly evaluated and the normal and shear stiffness values between the surrounding ground and tunnel supports should be defined in advance. The previous studies have focused on the probability-based reliability assessment of tunnel supports using analytical solutions that can be applicable only to limited conditions, rather than combined with numerical methods that are more useful for solving a variety of underground problems with various shapes and analysis conditions.
Examination of Shotcrete Liner At Devil's Slide Tunnel Utilizing ASTM 1550 Field Test Results And Back Analysis
J.B. Decker, P.H. Madsen, V. Gall
Paper presented at the 44th U.S. Rock Mechanics Symposium and 5th U.S.-Canada Rock Mechanics Symposium, June 27–30, 2010
Paper Number: ARMA-10-402
... performance of the FRS. However, the ASTM 1550 does not analyze shear failure due to ground loads imposed on the liner. Therefore, it must be coupled with typical compressive strength testing. Furthermore, measured convergence during excavation presents the opportunity to back calculate and analyze...
ABSTRACT: The Devil's Slide Tunnel project, located south of San Francisco along Highway 1, consists of twin bore tunnels approximately 1250 meters long. The tunnels are currently being excavated and supported utilizing the "New Austrian Tunneling Method" (NATM). In NATM design a flexible initial lining is used to allow some deformation to occur to mobilize the strength of the rock. The initial lining support utilizes fiber reinforced shotcrete (FRS). The ASTM 1550 Round Determinate Panel Test "Pizza Test" is being conducted on site to ensure the flexural properties or post-crack performance of the FRS. However, the ASTM 1550 does not analyze shear failure due to ground loads imposed on the liner. Therefore, it must be coupled with typical compressive strength testing. Furthermore, measured convergence during excavation presents the opportunity to back calculate and analyze the in situ loading of the FRS liner for a better understanding of its actual performance. In this paper, the to date results of the ASTM 1550 field test program along with a back analysis based on measured convergence to determine the loading of the FRS initial lining will be presented. A brief discussion of the ASTM 1550 testing and the back calculated in situ loading of the liner and how these demonstrate the overall performance of the FRS liner at the Devil's Slide Tunnel will be given. 1. INTRODUCTION The ongoing excavation at the Devil's Slide Tunnel Project of two 1250 meter tunnels each with a profile of 80 m2 is being conducted utilizing the "New Austrian Tunneling Method" (NATM). The Tunnels are located along the pacific coast just south of Pacifica, CA, a suburb of San Francisco. The Tunnels will serve as a bypass for a landslide prone section of California's famed Highway 1. 1.1. Geological Setting The tunnel runs north-south through the San Pedro Mountain ridge which is part of the Santa Cruz Mountains. The tunnel lies within the San Andreas Fault system and is 7.2 km west of the surface trace of the San Andreas Fault and 2.8 km east of the surface trace of the San Gregorio Fault. The 10 km strip between these two tunnels is referred to as the La Honda structural and terrain block [1,2,3]. Locally, the tunnel is divided into three blocks representing different geological conditions: south block, central block, and north block (Fig. 1) [1,4]. The south block consists of Mesozoic aged granodiorite and quartz diorite. The South Block also contains many local shear zones and a low angle thrust fault (Fault A). The south block ends at Fault B, which is the southern border of the central block. The central block consists of interlayered late Cretaceous and early tertiary aged conglomerate, sandstone, siltstone, and claystone. The conglomerate and sandstone range from massive to thinly bedded, while the claystone and siltstone tend to be interbedded with sandstone layers and blocks. At the northern end of the central block another highly sheared zone associated with fault C marks the end of the central block.
Investigation of Thin Spray-On Liners Using Numerical Modeling
J. Richardson, R. Mitra, S. Saydam
Paper presented at the 43rd U.S. Rock Mechanics Symposium & 4th U.S. - Canada Rock Mechanics Symposium, June 28–July 1, 2009
... thin spray-on liner (TSL) products. It is a common opinion that TSL products, as part of a complete ground control system, may present significant benefits for operations. Numerical modeling techniques are regularly used for research and design purposes. It can be effectively applied in the field...
Abstract Rock support is the basis of any underground mine and many open cut operations. Ground support methods have evolved over the years with the current trend to use bolts, mesh and shotcrete. In the last decade there has been a significant growth in the number of commercially available thin spray-on liner (TSL) products. It is a common opinion that TSL products, as part of a complete ground control system, may present significant benefits for operations. Numerical modeling techniques are regularly used for research and design purposes. It can be effectively applied in the field of geomechanics in order to assist in the interpretation and prediction of results. The bending and the double-sided shear tests are the two laboratory tests that are designed to evaluate the properties of different TSLs. This paper evaluates the use of numerical modeling to simulate the material properties and support action of TSLs. The purpose of this study is to further develop modeling techniques for the simulation of TSL materials. This paper discusses the methodology and results of simulating these laboratory tests using the FLAC finite difference modeling software. INTRODUCTION A Thin Spray-on Liner (TSL) is a polymer based liner that is sprayed onto the rock surface, generally at a thickness of 3 to 5 mm. It effectively bonds the surface of the rock together and acts as a seal between the rock and mining environment [1]. TSL products were developed in the early 1990's for rock support applications [2]. They have been used in civil engineering for many years and it is a growing support concept still lacking widespread application in the mining field [3]. Although the support action of TSLs is not well understood, quick application with high areal coverage enables early reaction against ground movement. They have the potential to allow for greater extraction efficiency with reduced safety concerns. The use of TSLs has been common in the mining industry but widespread application is still missing [2, 4]. Therefore it is important to develop standard testing procedures to understand better the support mechanism of TSLs. The defining properties that make TSL products useful as surface support are their high tensile strength, shear strength, adhesive strength and rapid curing time. Numerical modeling is an accepted technique for solving problems across a wide range of applications and fields. According to [5] these numerical models allow us to understand the complex mechanisms and predict their behavior within the scope of the model. Dealing with complexity Access to results that are typically not measurable Flexibility The main advantages of numerical modeling that benefit the research process are discussed in the review of geotechnical engineering modeling by [6]:The reliability of modeling also requires consideration. Mathematical models differ from other types of models in that they are not tied to any physical form. While this gives greater flexibility it also makes them more abstract than their physical or analogue counterparts. A " mathematical model can only be good as our understanding of the processes " [7].
The Application of a Structural Thin Support Liner (TSL) On Mines
A.J.S. Spearing, G. Borejszo, A. Campoli
... Abstract Thin support liners (TSLs) have been used since the 1980s mainly to limit the weathering of rock. Numerous attempts have been made to create viable structural TSLs that can effectively replace 30 to 60mm of un-reinforced shotcrete (sprayed concrete) with only limited success...
Abstract Thin support liners (TSLs) have been used since the 1980s mainly to limit the weathering of rock. Numerous attempts have been made to create viable structural TSLs that can effectively replace 30 to 60mm of un-reinforced shotcrete (sprayed concrete) with only limited success. The structural use of TSLs is now gaining acceptance as the historical performance issues associated with them are resolved. These performance issues have been mainly associated with the long term stability of the polymer particularly under high humidity conditions and application issues related to equipment and pot life. Tunnel Guard is the most widely applied TSL internationally with sustained sales of over 1,000 tons/month in Southern Africa alone. This is enough material to cover almost 100,000 m² of exposed excavations per month. The applications in Southern Africa are mainly on deeper level tabular gold mines but the product is also used in platinum, diamond and copper mines for weathering protection and for structural support. This paper investigates the performance and cost effectiveness of the product mainly compared with shotcrete. INTRODUCTION TO THIN SUPPORT LINERS Urylon Plastics Inc. from Canada and the CSIR MiningTek from South Africa basically pioneered thin support liners in the early 1980's. Earlier membranes (from Celtite for example) had been primarily designed as rock sealants to limit weathering and were technically effective but seldom cost effective. Urylon developed a reactive (catalyzed) system based on polyurethane and MiningTek developed a non-reactive (and hence slower setting) system based on latex polymer emulsions. TSLs are applied in a layer of typically 4 to 8 mm or less (a target of 3 to 4 mm is usually adequate and cost effective for most applications). TSL REQUIREMENTS Bond strength (adhesion) to a dry or damp substrate during the same application Tensile and shear strengths Elongation before failure Tear strength Durability (useful life) Flammability and smoke toxicity Resistance to chemicals, humidity (and humidity changes) and temperatures in mines (generally site specific) The ability to penetrate cracks and adhere to the crack sides can also be beneficial The performance of any membrane type of support, including shotcrete, is governed by the following main physical parameters depending on the specific application [1]:The rate of strength gain and not only the ultimate value of the tensile strength, adhesion and elongation can be important if immediate support is needed. Health and safety of the material; before, during and after application Substrate preparation (even more critical when using a TSL) Ease of application including the cleaning of the equipment after use The cost effectiveness of the placed liner Pot life Shelf (storage) life The other most critical parameters are:The physical properties of membranes are constrained by the chemistry of the raw materials available. High tensile strength and high elongation are both desirable, but generally this becomes a trade-off, as a higher elongation generally results in a lower tensile strength and vice versa. Most TSLs do not perform well under high humidity conditions whereas shotcrete is unaffected or its performance improves under such conditions.
Estimating ore pass longevity in hard rock mines
J. Hadjigeorgiou, F. Mercier-Langevin
Paper presented at the The 42nd U.S. Rock Mechanics Symposium (USRMS), June 29–July 2, 2008
... of ore passes is summarized in Table 1, making a distinction between supported and non supported ore pass sections. Table 1. Performance of ore pass sections in 10 underground mines. (available in full paper) Upstream Oil & Gas liner Reservoir Characterization orientation ground...
ABSTRACT: In most underground mines material transfer relies on ore and waste pass systems. A major challenge is ensuring that the ore pass systems remain operational. The unexpected failure of an ore pass can result in major problems to a mine including closure. Ore pass longevity is influenced by ground conditions; ore pass configuration, operational considerations and ground support. Based on several case studies a methodology has been developed to estimate ore pass longevity. 1. INTRODUCTION The profitability of a mining operation is strongly influenced by the reliability of its material handling system. In underground mines, ore and waste pass systems provide a low cost method for the gravity transport of material through large vertical distances. The stability of underground excavations is often quantified as a function of stand-up time, i.e. the time an excavation can remain stable without support. A more appropriate measure of the longevity of an ore pass is the amount of material that can be safely transferred without necessitating re-habilitation or major intervention. In estimating the costs for repairing, or in extreme conditions replacing an ore pass, it is necessary to consider both material and labour but also costs associated with delays in production. Such delays can have significant monetary consequences. It is an accepted fact that ore pass longevity depends largely on such design factors as rock mass quality, ratio of field stress to rock mass strength and support. However, operational parameters are equally or perhaps more important to the economical viability of an ore pass. Once the ore pass is actually commissioned, design parameters should dictate the way the ore pass is operated. Unfortunately, it would appear that very few ore pass systems are operated as per their design specifications. Consequently, quite often mine specific ore pass operation practices have quite an adverse impact on the longevity of ore pass systems. There are no reliable design tools to predict the longevity of an ore pass. This paper discusses the limitations of existing tools, and introduces an empirical ore pass longevity estimation procedure. 2. CONSIDERATIONS IN ORE PASS DESIGN 2.1. Ground Conditions The influence of ground conditions on the stability of raise bored shafts has been investigated by McCracken and Stacey [1]. Using the Q system [2] as an indicator of rock mass quality, they introduced a series of modifications to account for wall stability rather than the roof, excavation orientation relative to structural features and rock degradation. The relationship between rock mass and ore pass operational failure has also been investigated in 10 underground mines [3]. This field study defined a "failed" ore pass section if it had expanded to twice its initial volume as recorded in the original layout. In this study ore pass expansion was quantified using cavity monitoring surveys, volume reconciliation from actual tonnage capacity and/or comments from mine operators. The performance of ore passes is summarized in Table 1, making a distinction between supported and non supported ore pass sections. Table 1. Performance of ore pass sections in 10 underground mines. (available in full paper)
The development of a high strength thin support liner and two case studies
Sam Spearing, Henk Pretorius
Paper presented at the Golden Rocks 2006, The 41st U.S. Symposium on Rock Mechanics (USRMS), June 17–21, 2006
Paper Number: ARMA-06-1140
... support system. Commonly some form of reinforcing member (e.g.: a grouted rebar or cable bolt) is used with a liner (for areal cover) support (such as shotcrete or screen/mesh). Generally, the role of the reinforcing member is to keep the larger rockmass (key blocks) in place, whilst the liner s role...
ABSTRACT: Over the past ten years a thin support liner (TSL) has been developed with appropriate application equipment for use as part of an underground support system. The material has very unique properties (and is safe to handle and apply) that enable it to be used under adverse conditions such as in the presence of running water. The material can have an adjustable set time from seconds to minutes and has a very rapid strength development with an ultimate tensile strength of over 14 MPa (2000 psi) and an unusually high bond strength. Two case studies are presented; a shallow civil tunnel in Hong Kong that had weak ground and water ingress, and a shaft system on a mine in Namibia where water ingress threatened the stability of the entire infrastructure. The TSL was successfully used in both applications saving time and money on both applications INTRODUCTION 1.1. Support underground Support underground is critical to ensure the safety of the workforce and the uninterrupted use of the excavation during its useful (planned) life. The following points influence the need for some form of support in any underground excavation: ? The stress state around the excavation periphery. ? The change in the stress state during the useful life of the excavation (usually as a result of mining in the vicinity). ? The shape and cross sectional area of the excavation. ? Local and regional geological features (such as faults, bedding planes and joints/cleats). ? The in situ rock properties (the uniaxial compressive strength etc.). ? The final use for the excavation. ? The planned life of the excavation. The main functions of support over the useful life of the underground excavation are therefore to: ? Limit unplanned over-break (during the excavation process). ? Prevent local rockfalls. ? Reduce deterioration with time. ? Maintain the designed cross sectional area and shape. ? Absorb sufficient energy in dynamic conditions if applicable (i.e. during seismicity). This is generally achieved using a combination of support types to create an interactive support system. Commonly some form of reinforcing member (e.g.: a grouted rebar or cable bolt) is used with a liner (for areal cover) support (such as shotcrete or screen/mesh). Generally, the role of the reinforcing member is to keep the larger rockmass (key blocks) in place, whilst the liner?s role is to keep the smaller rocks between the reinforcing units in place (stop unraveling). Frequently the liner support design is not given the attention that it deserves and this can create potentially hazardous conditions with time. .
The Influence of Young's Modulus on Stress Modelling Results
Reginald Hammah, John Curran, Thamer Yacoub
... reservoir geomechanics finite element model Reservoir Characterization circular hole material stiffness thin-walled cylinder classical problem deformation liner elastic continuum excavation stiffness 1. INTRODUCTION The complex and wide-ranging behaviours of geological materials, the great...
ABSTRACT: In numerical analyses involving multiple geological materials, predicted stress distributions, deformation patterns, and failure mechanisms depend on the ratios of the Young?s moduli for the different materials, a detailed often overlooked. Using two simple examples this paper demonstrates the wide range of behaviours that can accompany different Young?s modulus ratios in problems involving multiple materials. INTRODUCTION The complex and wide-ranging behaviours of geological materials, the great variability in material properties, and the intricacies of numerical analysis methods, such as the finite element and finite difference methods, often combine to make the modelling of geotechnical problems a challenge. An important and difficult aspect of such modelling is the specification of constitutive models that best describe the stress-strain behaviour of soil and rock materials. Full description of the constitutive behaviour of a material requires specification of deformation and strength parameters. Upon initial loading a material responds elastically; deformations are reversible when loading is removed. After a certain level of stress is attained plastic deformations (permanent deformations that are not reversed when loading is removed) begin to occur. In general, after yielding, deformations occur at significantly reduced material stiffness. From the authors? interactions with various users of the finite element program Phase2, it appears to them that many geotechnical engineers pay more attention to the specification of the strength component of constitutive behaviour than to the deformation aspect. This may stem from the fact that it is generally easier to estimate or measure the strength envelopes of soil and rock masses than it is to measure their in situ deformation properties. Notwithstanding, in numerical models of geotechnical problems engineers must endeavour to specify deformations properties (primarily values of Young?s modulus) characteristic of the materials. Failure to do so often leads to ?surprises?, especially in problems involving more than one material. The ratios of the different Young?s moduli in a multiple material model can significantly alter overall model response, including induced failure mechanisms. This paper will demonstrate the impact of the ratios of material stiffness (Young?s modulus) on behaviour, using two problems involving linear elastic materials. These examples, although quite simple, will underline the need to pay attention to material stiffness if one desires to properly capture the physics of geotechnical problems.
Modeling Underground Structure Vulnerability In Jointed Rock
Robert P. Swift, David W. Steedman
Paper presented at the DC Rocks 2001, The 38th U.S. Symposium on Rock Mechanics (USRMS), July 7–10, 2001
... on an aluminum lined cylindrical opening in jointed Salem limestone. Representing limestone with discrete elements having elastic-equivalence and explicit brittle tensile behavior and the liner as an elastic-plastic continuum provides good agreement with the experiment and damage obtained with finite-element...
ABSTRACT : The vulnerability of underground structures and openings in deep jointed rock to ground shock attack is of chief concern to military planning and security. Damage and/or loss of stability to a structure in jointed rock, often manifested as brittle failure and accompanied with block movement, can depend significantly on jointed properties, such as spacing, orientation, strength, and block character. We apply a hybrid Discrete Element Method combined with the Smooth Particle Hydrodynamics approach to simulate the MIGHTY NORTH event, a definitive high-explosive test performed on an aluminum lined cylindrical opening in jointed Salem limestone. Representing limestone with discrete elements having elastic-equivalence and explicit brittle tensile behavior and the liner as an elastic-plastic continuum provides good agreement with the experiment and damage obtained with finite-element simulations. Extending the approach to parameter variations shows damage is substantially altered by differences in joint geometry and liner properties. INTRODUCTION Today, many nations protect their critical assets through deep burial in hard rock formations. The vulnerability of these underground facilities -- including command and control facilities, weapon production and storage areas, testing facilities, nuclear waste burial facilities, and others -- to ground motions caused by explosions and earthquakes is of priority national interest. However, the response of these facilities to ground shock environments is poorly understood, and high confidence in vulnerability assessments from these stimuli is impeded with uncertainty.
Thermal-mechanical measurements in the Drift Scale Test, Yucca Mountain, Nevada
S.R. Sobolik, R.E. Finley, S. Ballard
Paper presented at the Vail Rocks 1999, The 37th U.S. Symposium on Rock Mechanics (USRMS), June 7–9, 1999
... indicate nearly elastic response of the host rock to the thermal input. The concrete liner in the Heated Drift exhibits a far more complex com- bination of thermal expansion, mechanical stress from the surrounding rock, and shrinkage and dehydration phenomena. INTRODUCTION The welded tuffs of Yucca...
ABSTRACT: Measurements of temperature, rock displacement, and strain induced by heat, representing a potential high level nuclear waste repository, are being collected and analyzed by Sandia National Laborato- ries at the Exploratory Studies Facility at Yucca Mountain, Nevada. The data indicate nearly elastic response of the host rock to the thermal input. The concrete liner in the Heated Drift exhibits a far more complex com- bination of thermal expansion, mechanical stress from the surrounding rock, and shrinkage and dehydration phenomena. INTRODUCTION The welded tuffs of Yucca Mountain, Nevada are being considered by the United States Department of Energy (DOE) as potential host media for the storage of high level radioactive waste. As part of the site characterization efforts for the Yucca Mountain Site Characterization Project (YMP), a mechanically ex- cavated Exploratory Studies Facility (ESF) was completed in 1997. A Thermal Testing Facility (TFF) for conducting an in situ thermal testing pro- gram was subsequently constructed off the main drift of the ESF (Fig. 1); the TTF includes the Single Heater Test (SHT) block and the Drift Scale Test (DST). The DST, the world's largest/n situ under- ground thermal test, was energized on December 3, 1997 in a 50-m long, 5-m diameter Heated Drift (HD). The goal of the DST is to evaluate the coupled thermal-mechanical-hydrologic-chemical (T-M-H-C) response of the repository host rock to elevated tem- peratures representative of a high level nuclear waste repository. The data from the DST will be used to evaluate conceptual and numerical models of the coupled T-M-H-C processes used for performance assessment of the proposed Yucca Mountain re- pository. 1.1 Background The ESF Thermal Tests include the DST and the SHT, which was conducted from August 1996 through January 1998. The DST represents a combi- nation of experimental efforts originally described in the YMP site characterization plan (DOE 1988). These efforts include excavation investigations, in situ thermal-mechanical properties tests, in situ me- chanical properties tests, and engineered barrier sys- tem field tests. These tests, consolidated in the In Situ Thermal Testing Program Strategy (DOE 1995), subsequently were further consolidated, resulting in the ESF Thermal Tests.
Gas Barrier Design For The WIPP
Frank D. Hansen, Matthew J. Leroch, Leo Van Sambeek, Mao S. Lin
Paper presented at the The 34th U.S. Symposium on Rock Mechanics (USRMS), June 28–30, 1993
.... The development and extent of the DRZ after excavation of the alcove entry but before liner installation. 2. The eventual loads to be borne by the AGB as a consequence of salt creep. 3. The response of the surrounding rock to the presence of the lining in terms of healing of damage in the DRZ in salt...
ABSTRACT INTRODUCTION The Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, is planned as the first mined repository for transuranic (TRU) wastes generated by defense programs of the United States Department of Energy (DOE). In coming years, tests with radioactive wastes are planned to be conducted at the WIPP. Potential tests include evaluation of gases generated by wastes emplaced in mined alcoves. Barriers must be installed in the entries to the test alcoves to limit gas release during testing. This paper discusses several rock mechanics issues involved in the design of an Alcove Gas Barrier (AGB) for use in these potential tests. The unique requirements placed on a gas barrier, when coupled with the geologic setting and strict regulations, make the AGB design challenging from several perspectives of rock mechanics. The AGB structure will be placed in the WIPP underground, which comprises a layered evaporite sequence of rock. A schematic of the design as it might appear in the WIPP underground is shown in Figure 1. The underlying requirement is that the AGB reduce gas leakage from a test alcove to an acceptable limit. The most likely route for gas leakage is through a disturbed rock zone (DRZ), which develops in response to the excavation. Among other effects, the loading on the stnlcture is a function of the geometrical arrangement and time, including considerations of installation and service life. Resolution of design issues also requires a defensible measure of conservatism. These considerations give rise to several issues in rock mechanics which are the emphases of this paper. ROCK MECHANICS DESIGN CONSIDERATIONS The rock mechanics considerations of the AGB design consist mainly of numerical modeling studies which yield information on three principal concerns: 1. The development and extent of the DRZ after excavation of the alcove entry but before liner installation. 2. The eventual loads to be borne by the AGB as a consequence of salt creep. 3. The response of the surrounding rock to the presence of the lining in terms of healing of damage in the DRZ in salt and the arresting of further damage in interbeds. Soon after an opening is mined at the WIPP horizon, a DRZ will form because of stress relief and creep. A DRZ has the following characteristics: 1) an increased volume resulting from fracturing, 2) decreased load-bearing capacity, and 3) increased fluid permeability. The DRZ in salt will grow with time and could form a major leak passageway from the test alcove. However, if the salt is prevented from creeping into the opening by a rigid liner or sleeve, the DRZ in salt starts to heal. The AGB is designed to arrest further development of the DRZ around the opening and induce back pressure on the salt to promote healing of the DRZ. The rigid sleeve also stops further deformation of Marker Bed 139 (MBI39), a 1-meter thick anhydrite layer approximately I meter below floor level. If fractured, MBI39 could be a dominant leak path, and it is not expected to heal naturally. Eventually, stresses in the salt behind the liner are expected to return to their premining state; the mean stress increases and the deviatoric stresses decrease. The rigid-liner concept forms the general framework of the design considerations.
HAW test at Asse: Measured and calculated rock response
T. Rothfuchs, H.-K. Feddersen, V. Graefe, B. Hente, K. Wieczorek
Paper presented at the The 33rd U.S. Symposium on Rock Mechanics (USRMS), June 3–5, 1992
.... The in-situ measurements comprise the observation of temperatures, stresses, deformations and microseismic activity in the underground test field. production monitoring displacement liner Reservoir Characterization production logging Reservoir Surveillance electrical heater rock salt awid flat...
ABSTRACT A test disposal of thirty high-level radioactive canisters is envisaged in the Asse salt mine in Germany. Two preceding electric-al reference tests are in operation since November 1988. A comparison of the results of model calculations with measurement data resulted in an excellent agreement for the temperature field but a less good agreement for the stress and the displacement fields in the rock mass. The following reasons may cause these discrepancies= Axisymmetry of the model and the chosen creep law neglecting transient creep lead to a higher model stiffness while insufficient contact of the stress gages to the rock mass results in reduced stress values. The thermally induced stresses do not cause fracturing as indicated by accompanying microseismic observations. INTRODUCTION In order to demonstrate the safe disposal of high-level radioactive waste (HAW) in salt thirty high-level radioactive canisters will be emplaced in six boreholes located in two test galleries at the 800 m level in the Asse salt mine in Germany. These canisters fabricated by the Battelle Pacific Northwest Laboratories contain the radionuclides Caesium 137 and Strontium 90 in quantities sufficient to cover the bandwidth of heat generation and gamma radiation of real high-level waste. Besides the development of a transport and emplacement system for HAW-canisters the investigation of the interaction of the radioactive canisters with the host rock stands in the foreground of the test objectives. The high-level radioactive canisters have not yet been emplaced in the underground boreholes because the required license is still pending. Two reference tests with electrical heaters, however, were already started in November 1988. They simulate the heat release from the radioactive canisters. This paper provides information on the thermomechanical response of the salt rock during the pre-heating and the heating phase now lasting for more than three years. For the validation of calculational models a comparison between predictive calculations and actual in-situ meas- urement data is being performed. The in-situ measurements comprise the observation of temperatures, stresses, deformations and microseismic activity in the underground test field.
Continuous cast lining A solution to downhole problems
T. Moen, F. Remvik
Paper presented at the The 31st U.S. Symposium on Rock Mechanics (USRMS), June 18–20, 1990
... pressure drilling pore pressure borehole gravity independent drilling wellbore integrity Upstream Oil & Gas material property experiment squeeze-cementing module drilling operation petroleum engineering calculation sandstone borehole stability Wellbore Design strength liner core...
ABSTRACT INTRODUCTION For several decades the off and gas industry have been fighting a continuous battle against differential sticking, wash-outs, stuck pipe, stuck casing, kicks, blow-outs. break-outs and other well related problems. A lot of understanding concerning these problems has been gained, and many solutions have been suggested during the history of petroleum engineering. But the driller is still struggling with many of the same problems as General Drake had. Kolibomac (figure 1) is an innovative development programme started in 1981 comprising new technology for gravity independent drilling (Røland et al. 1988). As opposed to traditional (gravity dependent) drilling, the method of gravity independent drilling does not require the weight from the drillstring to apply weight on bit. This is achieved by using an "hydraulic drill collar" which consists of two inflatable packers and two pistons. The packers handle the reaction forces from the bit while the pistons make it possible for the Kolibomac machine to move in both directions. This means that by using a downhole motor the need for a rotating drillstring is eliminated. Instead the drillstring could be replaced by a flexible multicourse hose for the transmission of mud. hydraulic/electric power and signals. On the other hand this introduces the problem of differential sticking. In other words new methods and materials had to be developed to continuously seal the borehole as it is being drilled.
Results of a large, in situ, heated axisymmetric pillar test at the waste isolation pilot plant (WIPP)
Darrell E. Munson, Teresa M. Torres, Robert L. Jones
.... hydraulic fracturing calculation Upstream Oil & Gas solid waste management experiment metals & mining displacement Albuquerque thermal structural interaction access drift mining machine closure station 270 Waste Isolation Pilot Plant liner requirement WIPP interaction deformation...
ABSTRACT ABSTRACT: Extensive structural creep and thermal histories of a heated, axisymmetric, underground salt pillar are presented and analyzed through pseudostrains. In situ data are then compared to laboratory fracture and to 2-dimensional numerical, pre-test reference calculations. 1 INTRODUCTION The Waste Isolation Pilot Plant (WIPP) is now being constructed in southeastern New Mexico. Underground workings of the facility, in bedded salt, are about 659 m below the surface. As seen in Figure 1, a portion of the underground facility is devoted to large scale tests for nuclear waste repository technology development [Munson and Matalucci 1984]. Some in-situ experiments study thermal/structural interactions (TSI). A primary objective of the TSI experiments is to determine the creep deformation of excavations as a data base for the verification of predictive behavior models. Understanding heated salt behavior is an essential element in providing a sound basis for design of nuclear waste repositories. As a result, the experiments have been carefully planned and extensively instrumented to obtain complete salt displacements during and after excavation, and a complete temperature history. One test, the Heated Axisymmetric Pillar (Room H), is perhaps the most unique experiment fielded to date. This test is a well defined cylindrical pillar, surrounded by an annular room. In theory, room and pillar are ideally axisymmetric; however, the construction sequence and access drift have introduced some deviation from the ideal. Despite this, measured room response is, nevertheless, an exceptional test for verification of calculational techniques based on 2-dimensional, finite element, numerical methods. The underground experiment was designed to match the symmetry of prevalent numerical capabilities. As a principal consequence, discrepancies between calculation and experiment must arise from the stress generalization or constitutive model, rather than from the geometrical abstractions or numerical techniques. The purpose of this paper is to report the time-dependent salt deformations and temperatures measured in the pillar and around the annular room during and after excavation. The paper especially focuses on (1) determining the range of influence of the openings, (2) using pseudostrain concepts to analyze the influence of multipass excavation, and (3) comparing thermal/structural response to pre-test calculations based on reference constitutive models. Comparisons are made between calculated and measured creep response of underground openings. We also give comparisons of measured and calculated thermal fields. A summary of the state of numerical prediction capability of heated underground openings in bedded salt concludes the paper. 2 EXPERIMENT CONFIGURATION The room access drift and test room were excavated by a Mitsui-Miike continuous mining machine. The 61 m long access was mined in a single pass to a 3.05 m high by 3.66 m wide cross section during a 5 day period from April 16 to April 21 (day 0), 1984. The room access excavation was stopped at what would later become the pillar surface. Vertical closure measurements were made in the access early during excavation; and subsequently, permanent closure stations were established to monitor the long-term creep closure of the access.


Dr. Daniel Wildcat, Ph.D., is a professor at Haskell Indian Nations University in Lawrence, Kansas, and an accomplished scholar who writes on indigenous knowledge, technology, environment, and education. He is also co-director of the Haskell Environmental Research Studies Center, which he founded with colleagues from the Center for Hazardous Substance Research at Kansas State University. A Yuchi member of the Muscogee Nation of Oklahoma, Dr. Wildcat is the coauthor, with Vine Deloria, Jr., of Power and Place: Indian Education in America (Fulcrum, 2001), and coeditor, with Steve Pavlik, of Destroying Dogma: Vine Deloria, Jr., and His Influence on American Society (Fulcrum, 2006). His most recent book is Red Alert! Saving the Planet with Indigenous Knowledge (Fulcrum, 2009). Known for his commitment to environmental defense and cultural diversity, Dr. Wildcat has been honored by the Kansas City organization The Future Is Now with the Heart Peace Award.


THE lawmaker representing Ogun East Senatorial District, Senator Buruji Kashamu, yesterday, called on the Police to hold the National Chairman of the Peoples Democratic Party, PDP,Prince Uche Secondus, "for breach of public peace and safety should there be a breakdown of law and order in Ogun State" ahead of the 2019 general election.
He also urged the Attorney-General and Minister of Justice, Mr. Abubakar Malami, the Inspector-General of Police, Mr. Ibrahim Idris and the Director-General of the Department of Security Service, DSS, Mr. Yusuf Magaji Bichi, to take cognizance of Secondus' conduct which, according to him, is capable of causing tension and a breach of public peace.
In a quick response, the PDP dismissed Kashamu's threat saying the lawmaker is unknown to the party.
Kashamu gave the warning in a statement following the presentation of the Ogun State PDP governorship flag to a member of the House of Representatives, Mr. Oladipupo Adebutu, in Abuja, on Friday.
He said the AGF, IGP and DG, SSS should refuse the temptation to allow "some misguided politicians" to take the laws into their hands and continue to act contemptuously of valid and subsisting court orders and judgments while hiding under the cloak of politics and politicking. There is no gainsaying the fact that such illegal acts could cause unmitigated disorder and a breach of public peace.
The lawmaker noted that he would soon furnish the offices of the AGF, IGP and SSS with all the relevant documents, detailing the criminal and contemptuous acts of these retrogressive elements.
Kashamu said: "The desperation showed by Secondus is only typical of a mercenary who is hell-bent on delivering on the job he has been paid to do. His latest action was done in utter disregard to the Party's Constitution and subsisting judgment of courts – from the High Court to the Supreme Court – which the Independent National Electoral Commission (INEC) has since complied with.
Reacting to Kashamu's threat, the National Publicity Secretary of the PDP, Mr. Kola Ologbondiyan said the lawmaker is unknown to the party.


text:
WHO Ebola diaries: Cuban. Doctor. Ebola survivor
© WHO/W. Romeril
Dr Felix Sarria Baez was one of dozens of Cuban doctors sent as a Foreign medical team to support the Ebola response in Sierra Leone in October 2014. While working there, he contracted Ebola himself. He survived and returned to Sierra Leone to further help Ebola patients. Below is his story.
"It's been like coming back from a war, alive. My companeros shouted, smiled, cried and hugged me," Dr Felix Sarria Baez reflected on his return to Sierra Leone after recovering from Ebola.
Dr Felix told his story on a hot, dusty hotel patio in Port Loko, a 2-hour drive from the capital Freetown. He was wearing a new WHO polo, a gift when he came back to Sierra Leone. All his other clothes were destroyed in November 2014 when he was diagnosed with Ebola. "It's good to come back. I needed to come back," he explains. "Ebola is a challenge that I must fight to the finish here, to keep it from spreading to the rest of the world."
Becoming infected
"I don't know how I got infected. There was no violation of protocols," he explains, describing sweat "like a river" from the layers of heat-retaining safety garments that cause body surface temperatures to rise to 40 degrees centigrade (104 Fahrenheit). This is significantly higher than normal body temperature of 37° C (98.6 F) and can only be withstood for 40 to 60 minutes. WHO provided rigorous safety training and mentoring to the Cuban Medical Brigade and other foreign medical teams before starting work in the Ebola treatment centers.
Dr Felix remembers clearly the day he first felt ill. "It started Sunday morning with a fever of 38 and then 39.5° C (100.4 to 103.1 F). I lost my appetite all day, but I didn't feel weak or have any pain," he recounted.
"On Monday, I went to Kerry Town Treatment Unit, where there is a special ward for health care workers. I developed a cough that lasted throughout my illness. My white blood cell count and platelets fell fast. At 8 p.m. the test result came back positive for Ebola." White blood cells fight infection and platelets help blood clot. Without them, the body risks succumbing more quickly to Ebola.
"When my doctors told me the blood result, I thought about it and then decided, let's see what the results are tomorrow. I felt calm, quiet. I will save my life I said to myself. If you doubt and feel depressed, the illness will invade your body. It's important to be optimistic."
Ebola treatment
Before leaving Kerry Town, Felix's doctors started a central IV line as a precaution. Although he could still eat and drink at this stage, his condition was likely to worsen, at which point his veins might collapse making an IV attempt more challenging. Giving fluids by IV as needed to maintain life-saving hydration in Ebola patients is a mainstay of WHO guidelines since it often reduces severe complications and death.
WHO and the Government of Cuba agreed to transfer Dr Felix to Geneva, Switzerland. He remembered the impressive layout of the Phoenix medevac plane. "I was isolated in a private area where I could get up or rest. Four times during flight I had diarrhea," a common and concerning sign of Ebola since it can lead to rapid dehydration. At midnight, the Phoenix landed in Geneva and Dr Felix was transferred to Hôpitaux Universitaires de Genève (HUG), where his condition deteriorated.
"I lost consciousness and slept deeply. For 2 days I was delirious with a 40° C (104 F) fever and cerebral encephalitis," Dr Felix said of the worst phase of the disease. The fever caused swelling in his brain, although his caregivers later said he would awaken, answer questions, and drift off again. He developed a rash over his entire body, beginning on his chest, belly and back, as is often seen on Ebola patients.
On Thursday, his fever broke and he woke up feeling better. He drank juice and ate rice, meat, fruit, yogurt and chocolate. "Chocolate is good for Ebola," he said with a grin. By Friday, Dr Felix's hands ached so badly he was unable to hold a pen. "I spoke to my family every day from that time on," he remembered. "My wife would tell me to keep up my spirits and not worry about her and the boys. She never doubted I would recover."
He was released from HUG once his blood was clear of Ebola virus.
When Dr Felix landed in Cuba, a handful of people greeted him at the airport including his family and a few government officials. No one in Cuba avoided him or treated him as a social pariah for having fought off Ebola, as many survivors have experienced in West Africa or other countries.
In Cuba, his wife nursed him back to health with a steady diet of meat and chicken. During his 2 weeks in hospital, he moved only between the bed and a chair. Dr Felix's arm and leg muscles had grown so weak he could barely stand.
"That first day back in Cuba, my wife brought me my 2 year-old son. I held him all day long until the evening, all the while rocking him in my arms," he cradled his arms across his chest and swayed back and forth. "After that, my legs felt strong. I didn't need physical therapy. My son was my therapy. I was better from that day on."
Back to Sierra Leone
A month and an added 15 pounds later, Dr Felix boarded a plane for Sierra Leone. On his way, he stopped by HUG in Switzerland to donate his plasma to help future Ebola patients. "I met my doctors and nurses and their families for dinner. That was a very beautiful day. They saved my life," Dr Felix said. "Every doctor and nurse should talk and have a good relationship with their patients. They did with me."
"I am so grateful to the Director-General and everyone at WHO, to the British army docs, and to the hospital staff in Geneva for each playing a part in saving my life." Dr Felix departed Sierra Leone on 22 March 2015 in the first wave of Cuban medical workers to head home.
West Africa: Ebola Outbreak - Mar 2014
Safety nets, health crises and natural disasters: Lessons from Sierra Leone
Sierra Leone + 11 more
The impact of COVID-19 Pandemic on women: Lessons from the Ebola outbreak in W/Africa
WANEP
Community Engagement in Outbreak Response: Lessons from the 2014–2016 Ebola Outbreak in Sierra Leone
Sierra Leone: $13.5 million project to assist Ebola-hit communities kicks off

redpajama_set_name: RedPajamaCommonCrawl


text:
Posted inHartford, Labor, Law Enforcement, Public Safety, Town News
Lawmakers Question Police Dispatch Consolidation Effort
by Christine Stuart November 15, 2013, 12:00 pm January 21, 2021, 7:04 pm
Department of Emergency Services and Public Protection Commissioner Reuben Bradford (Hugh McQuaid photo)
He was there Thursday to talk about funding for policing the two casinos, but lawmakers from eastern Connecticut wanted Department of Emergency Services and Public Protection Commissioner Reuben Bradford to know they were concerned about the consolidation of their dispatch centers.
Last year it was the western part of the state. Now State Police dispatch centers in eastern Connecticut are being consolidated. At the end of October, Troop D in Danielson and Troop K in Colchester moved their dispatch functions to Troop C in Tolland. Troop E in Montville will be consolidated next.
The changes are part of a larger effort to reduce the number of state police dispatch centers in the state from 12 to 5. In the western part of the state, dispatch functions for Troops A and B were moved to Troop L in Litchfield.
Rep. Linda Orange, D-Colchester, wanted to know how much the consolidation effort in the eastern part of the state cost.
Neither Bradford nor Office of Policy and Management Secretary Ben Barnes were able to give her an answer Thursday.
But Bradford said the consolidation effort was not about saving money. "It was a business decision that made use of our resources in the most efficient manner possible."
He said that in 1974, when he went to the training academy, it was to become a trooper rather than a dispatcher.
"So as a taxpayer I don't want a policeman dispatching," Bradford told Orange. "I want him out doing work he's supposed to be doing."
Bradford said the barracks will still be staffed as they traditionally are staffed and will not be closing. But it's just the dispatching function that will be moved.
"It's not so much a cost savings as it is a proper deployment of hazardous duty resources doing hazardous duty functions," Bradford said.
Orange said she understands that, but she questioned the staffing levels. She said she knows someone who went to the barracks during the day to seek help, and the doors were locked because no one was there. They used the blue emergency phone and were told someone would be there in 20 minutes.
"Twenty minutes is a long time when someone's in crisis," Orange said. "Twenty minutes is too long to come back to a troop."
Rep. Mae Flexer (Hugh McQuaid photo)
Rep. Mae Flexer, D-Killingly, said there have been several incidents in the past six weeks where she believes public safety has been jeopardized.
"For a decision that was initially made to save money, it's now not saving money, and potentially impacting the public safety and I'm hopeful the department will continue to evaluate this and determine whether or not it's really working," Flexer told Barnes.
But Barnes maintained that he believes the "model is more cost-effective for the state and certainly can be done." He said in other parts of the country this method has been deployed across much larger geographic areas.
"There's no compelling reason to believe that that in and of itself jeopardizes public safety," he said.
In repeating a favorite phrase of the Malloy administration, Barnes told Flexer that "change is hard." He said that just because people on the front line — in any part of government — are initially frustrated with policy changes, it's not a reason to undo those changes completely.
Flexer said the complaints she's hearing from her constituents may not be related to the consolidation of the dispatch centers, but may in fact be a staffing issue.
At the moment it's unclear which is really causing the problem, but legislative Republicans have promised to make it an issue in the 2014 election. The only two lawmakers to speak up about the issue Thursday were Democrats.
"It won't be pretty if something happens that could have been avoided and there's a lawsuit against the state," Orange said. "Then we will have saved no money."
Orange, a veteran lawmaker who also sits on the Public Safety Committee, said she was sent by former Speaker Moira Lyons to Harrisburg, Pa. in 2005 to visit a centralized dispatch center.
"At this point in time, Pennsylvania found that it did not work,' Orange said. "Just keep that in mind as well."
State Rep. Manny Sanchez will assume the role of the Labor and Public Employees Committee's House chair, a post left vacant by the untimely death of Rep. Quentin "Q" Williams… Keep reading


text:
Les os sésamoïdes de la main sont des os sésamoïdes situés sur la face palmaire.

Description
Les os sésamoïdes de la main ne sont pas tous constants.

Seul deux sont constants au niveau de la face palmaire de l'articulation métacarpo-phalangienne du pouce : un interne arrondi et un externe ovalaire. Leur face postérieure est plane et articulaire avec la tête du premier métacarpien. Sur leur face palmaire s'insèrent les muscles de l'éminence thénar.

D'autres os sésamoïdes peuvent être présents au niveau des autres articulations métacarpo-phalangiennes ou au niveau de l'articulation interphalangienne du pouce.

Notes et références

Liens externes

Voir aussi

 Terminologie osseuse

sésamoïde de la main

redpajama_set_name: RedPajamaWikipedia


text:
[Tall-Corn] Sad news for the Iowa Affiliate
Scott Van Gorp svangorp at nfbi.org
Thu Jun 18 02:06:12 UTC 2020
Previous message (by thread): [Tall-Corn] June Siouxland Chapter Meeting
Next message (by thread): [Tall-Corn] FW: [Nfbnet-members-list] Legislative Alert June 19, 2020
Good Evening Federation Family:
It is with extreme sadness that I write this evening to all of you. I
received word last night that a treasured member of the Des Moines chapter
of the National Federation of the Blind of Iowa, Mike Glynn, passed away
last Thursday, June 11, 2020. Mike served the chapter and affiliate in a
number of different capacities, from being on the chapter board to picketing
along side many of us in front of the Des Moines Federal building in protest
of Section 14C of the Fair Labor Standards Act. He served the Federation
much the same way I suspect he served his country in the military, with
honor, grace, and humility. Thank you, Mike, for your service to this
country, the National Federation of the Blind of Iowa, and the world as a
whole. Below is the link to Mike's obituary and the information for the
visitation tomorrow. I have pasted the text for those who are unable to
access the link.
https://www.hendersonshp.com/obituary/Michael-Glynn
Michael David Glynn
August 9, 1956 ~ June 11, 2020 (age 63)
Michael D Glynn, 63, a former Registered Nurse, passed away June 11, 2020 at
the Veterans Hospital in Des Moines.
A Visitation honoring his life will be held from 4-6pm Thursday, June 18th
at Henderson's Funeral Home.  Military Honors will begin at 4:00 pm. Masks
are required and per the family's request, young children are not allowed
Michael David Glynn was born August 9, 1956 to Arthur James Glynn and
Glenease Helen (Williams) Glynn in New York. Michael's dad got a new
teaching position and moved the family to Des Moines.
Michael attended East High School and later the University of Iowa. He was a
huge Hawkeye fan. After graduation, he enlisted in the U.S. Army and served
as a Combat Medic. His service took him to Germany, Texas and California.
After his honorable discharge from the army his used his skills to attend
Mercy School of Nursing. He was employed as a Registered Nurse at Broadlawns
and Mercy Medical Centers.
Michael  married an Army nurse named Renee Allen. To this union two sons
were born: Justin and Andrew. Michael and Renee were married for over 20
years and remained friends after the marriage ended.
Michael enjoyed golf, reading, football, basketball and fishing. He was a
Cub Scout leader and won various awards from the National Federation for the
Blind. He was affectionately called "professor" because he possessed a
wealth of knowledge. He would share that knowledge through the 'art of
conversation'.
Michael passed away on June 11, 2020. He was preceded in death by his
father, Arthur. He leaves fond memories with his sons, Justin and Andrew
(Tina Fry) Glynn; mother, Glenease Glynn; brother Mark (Angela Book) Glynn
and sister, Marjorie (Chuck) Joelson; his former wife and friend, Renee
Allen Glynn, nieces, nephews, extended family and friends
VISITATION (WITH FAMILY PRESENT)
Henderson's Highland Park Funeral Home
Scott Van Gorp, President
National Federation of the Blind of Iowa
<mailto:svangorp at nfbi.org> Email
<http://www.nfbi.org/> Website
<https://www.facebook.com/National-Federation-Of-the-Blind-Of-Iowa-372681823
082570/posts> Facebook
<https://twitter.com/nfb_iowa> Twitter
Live the life you want.
The National Federation of the Blind of Iowa is a community of members and
friends who believe in the hopes and dreams of the nation's blind. Every day
we work together to help blind people live the lives they want.
URL: <http://nfbnet.org/pipermail/tall-corn_nfbnet.org/attachments/20200617/74983889/attachment.html>


and get paid without affecting your present job?
it cashed after I supply them raw materials.
clients who makes payment through you.
Is that Chelsea Harbour Design Centre a real business?
people who are trying to cash the worthless paper what Pure Shite it is.
the OLD CAPS LOCK CRAP WE USED TO SEE.
the format. Treason. We used to shoot traitors at dawn.
50/50 may be a bit steep, but as good a starting point as any.
You can yield ground on salary, but hard bargain, over very short working hours and lots of fringe benefits before you agree to work for them. It's a buyer's market for part time and home working so I hear.
Altfield Fabrics appears to be a legit business and if you google it you will find on another website where this guy is using the legit website in his scam mail only there he is Angus Pert.
I saw this scam letter in my spam box a couple months ago.
Man, I wish I could trace where this guy is from.
Ask him for a minimum payment. Something to a tune of $2,000 a month payable biweekly in advance. Anything in excess of this sum should come at 20% of the value of the checks.
SpyPig tells me he's in Nigeria.
So ever since I said I'd take 50%, this is how it went.
What, you won't even barter?
Yea, I meant "bargain," but hey, it's an ok de-education, eh?
Ah, at last you respond.
Alright, let's get some back and forth going. You offer 10%. I want 50%. What say you to that?
How much is the 10%?
You know what, my dear Mr. Parker? I have just learned that the gold import-export business I work in is treating me exceedingly well, monetarily speaking. I will work for you for anything, I think. However, I can't devote very much time to it. Importing and exporting gold is quite the time eater.
I may have given up too soon on the bargaining...but I thought he might potentially be excited by what my work is.
He's not much for words when he's off script, is he?
Well tell me, good man, how much time per day do I need to spend on this? 10 hours? 10 minutes? 26 hours? How much time?
And then he followed up quickly with another email.
of your time if they are paying straight into your bank account.
Unlike Cashier Checks which takes time to clear.
after we have confirmed payment, we would ship the materials to them.
Alright, how do I get started working for you then?
Right now the company need someone we can trust and we would like to know if you can get an account opened with any of the following banks:( Chase bank, Bank of America, Wells Fargo) in the next 3 working days, because these are the banks we and our clients operate with, and most of our contractors who are overseas pay into any of these bank. Now we would like you to take the post of an Account Officer.
The bank I'm currently with won't work?
Do you have a credit card, You can be paid through there.
I have a credit card, yes.


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Olympic events
Glaswegian shoes come off for bouncy Stonehenge
Posted by StonehengeNews under Ancient Britons, London 2012, Olympic events, salisbury guided tours, stonehenge 2012, stonehenge druids
Olympic project was almost scuppered by discovery of similar inflatable monument created two years previously
Two thousand people a day have come to frolic on Jeremy Deller's latest artwork – a bouncy castle that is a precise replica of Stonehenge. Men, women, children: all leap, stride and somersault on Glasgow's new favourite playground before it travels south to become one of the attractions of the London 2012 festival.
A neat idea, you might think. Sacrilege, as Deller has called his work, is not only a lot of fun (it is impossible not to smile when you shed your shoes, dignity, and understanding of gravity), but also thought-provoking.
The artist has transformed a great symbol of British history into a party. In real life, you cannot get near Stonehenge. Open to myriad interpretations and fantasies over its long history, it has now been given yet another existence through Deller's impish version of a grand public sculpture
It turns out that Deller is not the first artist to have made an inflatable megalithic monument. In 2010, two years before Deller's work was launched at the Glasgow International art festival, Jim Ricks, a California-born artist, Galway-based, unveiled his Poulnabrone Bouncy Dolmen – a precise, double-size replica of a megalithic table tomb built around 6,000 years ago in the Burren, Co Clare. The work toured various locations in Ireland last summer.
So is this a case of plagiarism? Or sheer coincidence? Are bouncy castles having what in fashion is known as a "moment"? Why, after several millennia of human creativity, have two inflatable megalithic monuments come along at once?
Deller became aware of Ricks' sculpture, he said, while researching a manufacturer for Sacrilege. According to Ricks: "Jeremy contacted me in October and I didn't think much of it … I didn't register who it was."
"I consider it an identical concept," Ricks told the Guardian. "In terms of the description of the work, they are incredibly similar," admitted Deller.
But Deller said that the idea for a bouncy Stonehenge had long pre-dated Ricks's Dolmen. He had originally thought of submitting an idea for bouncy-castle versions of historic sites to an Arts Council England-run public-art competition in 2009, but was too busy at the time. Finally, he decided to realise the idea for Glasgow International, with the London mayor's office as co-funders.
"The Olympics people got really nervous in case Jim decided to sue us," said Deller.
Happily for them, he was not minded to. In fact Ricks forgot all about it, until: "I spoke to the manufacturer by chance about six weeks ago and it dawned on me, so I decided to go over to Glasgow. Part of me was like, 'I'm ruined!' It was the same idea done bigger and more visibly. But another part of me is delighted because Sacrilege is awesome, Jeremy was a cool down-to-earth guy, and it's nice to know we're on the same wavelength … in a 'great minds think alike, fools seldom differ' way."
"You can be generous about it," said Deller, "and realise that two people can have a very similar idea. It is, after all, a very simple idea."
According to Ricks: "Jeremy is a lovely man, and I have no reason to doubt his story."
Where the works differ, perhaps, is in the nuance. "Sacrilege is a way for people – not just kids – to enjoy a historical monument that is supposed to be revered," said Deller. "It's comedic, it's absurd. It could be something you'd see in a satire on the Olympics or on art. I like to think of it as beyond parody."
Ricks said that his sculpture had come out of observing the power of the Poulnabrone Dolmen as a regional and national symbol. He added: "At the height of the Celtic Tiger period, on every special occasion there seemed to be a bouncy castle around. Bouncy castles became a sort of vernacular monumental sculpture. So I decided to bring those two things together, and create a sort of hybrid version of Irish identity."
The story of the megalithic bouncy castles is not yet at an end. Deller hopes that Sacrilege will travel to Northern Ireland as part of its Cultural Olympiad tour. If it does, he will invite Jim Ricks to bring his Poulnabrone Bouncy Dolmen over the border to visit. Let the bounce-off commence.
Full article in the Guardian: http://www.guardian.co.uk/culture/charlottehigginsblog/2012/may/02/bouncy-stonehenge-glasgow?newsfeed=true
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In "Food, Farming, and Freedom: Sowing the Arab Spring, Rami Zurayk has made a major contribution to our understanding of the roots of this unprecedented upsurge of Arab youth, Arab energy, and Arab political maturity."
The wave of anti-government protests that swept through the Arab world from December 2010 on is transforming politics and society in the Middle East. The protests came as a surprise to many observers-- but not to Rami Zurayk, an experienced Lebanese agronomist and social activist who had been charting the collapse of traditional agricultural livelihoods in the Middle East since the late 1980s.


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Female entrepreneurs beat the odds
HARARE � Six years ago, it was only a dream for Michelle Chitembwe (47), who slept on the floor of her slum house in Harare, to own a bed.
But challenging the difficulties, Chitembwe launched a soap-making venture and has shifted to a life of the rich from that of rags. She now enjoys her luxurious house in a Harare suburb.
Her initiative was a magic touch on her life, but it also changed the lives of many women as she employed scores to ensure a future for them.
For entrepreneur women, there are organisations in Zimbabwe showing them a way to help elude poverty.
Apart from working my way through single-handedly to where I am now, I have also obtained support from organisations like Usaid (United States Agency for International Development) to shape my vision, she said.
Chitembwe said she can now afford a private school for the education of her children thanks to her soap-making venture.
Actually, Zimbabwean women like Chitembwe have turned to forming home-based industries, with some of them even creating and producing dishwashing liquid, soft drinks and perfumes.
These entrepreneur women have become sources of most of the domestic products many of us sell in our shops, said Humphrey Gatawa, a Harare-based indigenous businessman.
Agness Chiramba, who lives in Harare's Mbare township and makes dishwashing liquid, said the market for her product has never ceased to amaze her.
I'm so amazed at the way local retail businesses have clamoured for my dishwashing liquid. I tell you, I'm making money just by making dishwashing liquid, pocketing over $200 every day in sales, Chiramba said.
She was an unemployed woman with academic education in chemical engineering. Chiramba, without options, turned to making dishwashing liquid in order to support herself as a single mother.
Benefiting the support of non-governmental organisations, women entrepreneurs are thriving in Zimbabwe although their activities are not regulated by government due to bureaucracy and corruption which many fear would derail their success.
Usaid Zimbabwe funded the course through its partnership with Junior Achievement Zimbabwe, a forum for youth business growth aggregators and that has helped women like me, Chiramba said.
As a result, Chiramba and Chitembwe have become self-assisted, at a time Zimbabwe's economy teeters on the brink of collapse, with inflation nearing 500%, according to the International Monetary Fund (IMF).
Zimbabwe is battling with a 90% unemployment rate, according to the Zimbabwe Congress of Trade Unions. However, women like Chiramba and Chitembwe have challenged the crisis with their entrepreneurial skills and have mastered over the years.
Based on statistics from the Ministry of Women Affairs, Community, Small and Medium Enterprises Development in Zimbabwe, about 261 000 women are involved in self-assisted projects, like soap- and detergents-making, among other income-generating projects.
Of late, development experts have attributed the rise in women venturing into home-based manufacturing industries to the hostile economy of the southern African nation.
The women have seen that men are losing their jobs as formal industries are closing down and the only option they have hatched for survival over the years is to leap into self-aided projects in order to survive the harsh economy, Donald Sengwayo, a Harare-based Zimbabwean development expert, said.
Except for the technical and financial support they have earned from non-governmental organisations, the women say, the Zimbabwean government itself has not moved in with any help.
NGOs have seen the need to support women and our government has not so far done anything meaningful to back our strides, leaving us to progress with the help of non-governmental organisations like Usaid, Chitembwe said.
For Zimbabwe's entrepreneurial women, working at the backyards of their homes is not enough � they are seeking more.
Personally, what I wish is to end up, one day, running a huge industry producing soaps and even exporting, Chitembwe said.
But for many women like Chiramba, this may not be easy.
We have no access to loans at banks here because most of us don't have collateral to enable us secure more capital from the banks, she said.
Apart from difficulties in accessing capital from banks, Chitembwe and Chiramba said they also had to struggle to get customers for their homemade products, although they have now gone past the stage.
Shop owners and ordinary people didn't really trust my products at first, rather preferring ordering stock from countries like Dubai, South Africa or India; you see, naturally as Zimbabweans we shun locally manufactured products. So, lots of hard work had to be done explaining to people why I was making my product from home before they could buy, Chiramba said.
Now, thanks to their endurance, many female entrepreneurs in Zimbabwe have become optional sources of affordable homemade consumable products at a time inflation has shot through the roof in the southern African country.
Due to rising prices, women who produce products like soaps, candles and dishwashing liquid have become providers of such items at quite low prices and I'm personally happy dealing with them, Marian Sithole, a 26-year old Harare woman, said.
Even Taurai Kandishaya, national co-ordinator of the Zimbabwe Citizens Forum, a civil society organisation with links to the country's governing Zanu-PF party, is excited about the products women are producing in their backyards.
Homemade products made by these entrepreneurs are offering our citizens a cheaper alternative although they may eventually be affected by price rises in the raw materials they use, which may eventually force them to increase their prices as well, Kandishaya said.
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