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2020

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Longwall Behaviour In Massive Strata, Ian Gray, Tim Gibbons Jan 2020

Longwall Behaviour In Massive Strata, Ian Gray, Tim Gibbons

Resource Operators Conference

Longwall mining of coal below massive strata now has a 50 year history, and much of it has been problematic. For the first 30 years, there was much experimentation, with some successes, and many failures due to lack of understanding about how such massive strata behaves during caving, and how this differs from the more conventional and successful longwall mining beneath softer strata, which caves readily. This has been compounded over the last 20 years as mines extract wider faces and thicker seams in a single pass, often at quite shallow depths. Today, China is leading the way with thick …

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A Review Of Overburden Fracturing And Changes In Hydraulic Characteristics Due To Longwall Mining, Hadi Nourizadeh, Ismet Canbulat, Joung Oh, Chengguo Zhang, Naj Aziz, Ali Mirzaghorbanali, Kevin Mcdougall Jan 2020

A Review Of Overburden Fracturing And Changes In Hydraulic Characteristics Due To Longwall Mining, Hadi Nourizadeh, Ismet Canbulat, Joung Oh, Chengguo Zhang, Naj Aziz, Ali Mirzaghorbanali, Kevin Mcdougall

Resource Operators Conference

Longwall mining is a major mining method to extract thick, flat-lying and extensive seams. Due to the nature of this mining method, the overlying strata move continuously downwards into goaf and as a result, surrounding rocks are distressed, deformed and fractured. In the near area above the mined coal seam, both vertical and horizontal fracturing networks are evident, however within the higher zones, bed separation and slippage are the dominant displacements. The enhanced cracks alter hydraulic characteristics (porosity and permeability) of the rock mass, consequently disturbing the groundwater and surface water flow regime. There have been various techniques utilised to …

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Proceedings Of The 2020 Coal Operators Conference, Naj Aziz, Bob Kininmonth Jan 2020

Proceedings Of The 2020 Coal Operators Conference, Naj Aziz, Bob Kininmonth

Resource Operators Conference

Proceedings of the 2020 Coal Operators Conference. All papers in these proceedings are peer reviewed. ISBN (ebook): 978-1-74128-321-1 ISBN (paperback): 978-1-74128-320-4.

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Design Combined Support Under Arbitrary Impulsive Loading, Faham Tahmasebinia, Ismet Canbulat, Chengguo Zhang, Serkan Saydam, Onur Vardar Jan 2020

Design Combined Support Under Arbitrary Impulsive Loading, Faham Tahmasebinia, Ismet Canbulat, Chengguo Zhang, Serkan Saydam, Onur Vardar

Resource Operators Conference

Rock bolts and cable bolts are usually considered to experience static loads under relatively low-stress conditions. However, in burst-prone conditions, support elements are subjected to dynamic loading. Therefore, it is important to understand cable bolt behaviour under dynamic loading conditions, particularly their energy absorption capacity. Rock bolts and cable bolts as well as steel mesh are widely used as permanent support elements in tunnelling, underground excavations and surface slope stability. This paper aims to determine the amount of the dissipated energy which can be taken into account to design combined yielding supports when subjected to dynamic loading. A ground support …

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Parametric Studies Of Cable Bolts Using A Modified Short Encapsulation Pull-Out Test, Danqi Li, Hossein Masoumi Jan 2020

Parametric Studies Of Cable Bolts Using A Modified Short Encapsulation Pull-Out Test, Danqi Li, Hossein Masoumi

Resource Operators Conference

The laboratory short encapsulation pull out test (LSEPT) has been widely accepted as the most efficient method to characterize the mechanical behaviour of cable bolts under axial loading. In this study, a number of LSEPTs was performed on conventional cable bolts including Plain SuperStrand and TG cable bolts using the improved pull out test design. The effects of several parameters including the uniaxial compressive strength (UCS) of confining medium and grout and the borehole diameter on the mechanical behaviour of both cable bolts were investigated. Analysis of Variance (ANOVA) was employed to quantify the contribution of these parameters on the …

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Static And Dynamic Testing Of Tendons, Saman Khaleghparast, Sina Anzanpour, Naj Aziz, Alex Remennikov, Ali Mirzaghorbanali Jan 2020

Static And Dynamic Testing Of Tendons, Saman Khaleghparast, Sina Anzanpour, Naj Aziz, Alex Remennikov, Ali Mirzaghorbanali

Resource Operators Conference

Underground support system using tendons has been one of the significant achievements in Civil and Mining engineering endeavours in facing challenges of ground control. However, shear failure of rock bolts is still one of the least monitored phenonmenon in underground excavations with respect to seismic events. The understanding of the performance of rock bolts under dynamic loading condition requires a great deal of research. A series of tests were undertaken utilising a drop hammer mass of 600 Kg from a maximum height of 3.7 m over concrete blocks in the double shear box with chemical resin encapsulated a rock bolt …

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Performance Of Bolting Systems In Tension And The Integrity Of The Protective Sleeve Coating In Shear, Naj Aziz, Antoine Schneiderwind, Sina Andanpour, Saman Khaleghparast, Duncan Best, Travis Marshall Jan 2020

Performance Of Bolting Systems In Tension And The Integrity Of The Protective Sleeve Coating In Shear, Naj Aziz, Antoine Schneiderwind, Sina Andanpour, Saman Khaleghparast, Duncan Best, Travis Marshall

Resource Operators Conference

A series of laboratory tests were carried out on sleeved bolt and domed washer plates and nuts to determine; • the tensile strength properties of 24 mm (200 mm core) diameter rock bolts (M24 Bolt), • pull through testing of the bolting system consisting of bolt, domed washer plate and nut integrity, • Integrity of the rock bolt fitted with protective plastic sleeve subjected to shearing. All these tests were carried out on rock bolts and dome washer plates supplied by Dextra / Pretec. Pull testing was carried out in accordance with British Standard (BS 7861.1:2007). It was found that …

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The Effect Of Elevated Temperature On Resin-Anchored Rock Bolts, Kent Mctyer Jan 2020

The Effect Of Elevated Temperature On Resin-Anchored Rock Bolts, Kent Mctyer

Resource Operators Conference

Resin-anchored roof bolts are used for primary roof support in all Australian underground coal mines. This popularity is due to a combination of technical performance, installation efficiency and cost. Further, many years of research exists pertaining to the load transfer of resin-anchored bolts. However, the composition of the load transfer medium – the resin anchor – means the resin-anchored bolt system is susceptible to possible degradation if high temperatures are applied. Thankfully, while high temperatures of more than 100°C are uncommon in coal mines, there is a rare event that can cause high sustained temperatures – a coal mine fire. …

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Development Of Support Systems For Longwall Mining In The Bowen Basin, Central Queensland, George Klenowski, Phil Mcnamara Jan 2020

Development Of Support Systems For Longwall Mining In The Bowen Basin, Central Queensland, George Klenowski, Phil Mcnamara

Resource Operators Conference

The first longwall mine in Queensland was Central Colliery, located at the German Creek Mines. Production commenced in 1985 and shortly afterwards it broke the world record for longwall coal production. At that time longwall mining was generally not considered viable in Queensland due to technical problems associated with weak coal and excessive gas and water. Engineering solutions were developed and included properly designed chain pillars, in-seam methane drainage and efficient, dewatering pumping systems (Klenowski 2000; Klenowski and Winter, 2017). Following success at Central Colliery longwall mining commenced at the Oaky No.1 Underground Mine and Southern Colliery. This was followed …

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Drill Rig Characteristics And Drilling Techniques Required For Maximum Borehole Depth With Directional Drilling, Frank Hungerford Jan 2020

Drill Rig Characteristics And Drilling Techniques Required For Maximum Borehole Depth With Directional Drilling, Frank Hungerford

Resource Operators Conference

Directional drilling has been the established form of in-seam drilling for gas drainage, exploration and water management for the past three decades. Although there has been a desire to achieve longer boreholes to depths similar to that achieved with surface drilling, seam conditions, equipment capacity and drilling methods have limited in-seam drilling depths. Development into a new area of Metropolitan Colliery required boreholes to depths of 2000 m to provide the required gas drainage. This offered an opportunity to use a combination of slide and rotary drilling similar to that used with Surface to Inseam (SIS) drilling to achieve the …

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A Discussion On Causation Mechanisms For Overburden Bumps As Distinct From Coal Bursts, Russell Frith, Guy Reed, Martin Mackinnon Jan 2020

A Discussion On Causation Mechanisms For Overburden Bumps As Distinct From Coal Bursts, Russell Frith, Guy Reed, Martin Mackinnon

Resource Operators Conference

The entire subject area of micro-seismic events due to stored strain energy, as distinct from gas-driven coal outbursts, can be readily sub-divided into firstly events with their energy source from within the coal seam (termed “bursts”) and secondly, event with their energy source outside of the coal seam in either the overburden and/or floor strata. The reason for sub-dividing micro-seismic events in this manner is that if the causation mechanisms and associated geotechnical conditions are materially different, then effective pre-mining predictions and subsequent operational controls may also differ. Attempting to explain a multitude of micro-seismic event types without consideration of …

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Dynamic Events At Longwall Face, Csm Mine, Czech Republic, Petr Waclawik, Jan Nemcik, Rudovan Kukutsch, Libin Gong, Gaetano Venticinque Jan 2020

Dynamic Events At Longwall Face, Csm Mine, Czech Republic, Petr Waclawik, Jan Nemcik, Rudovan Kukutsch, Libin Gong, Gaetano Venticinque

Resource Operators Conference

Presented here are the details of the seismic events that occurred at longwall 11 located at the CSM mine in the Ostrava coal region, Czech Republic. This longwall was excavated in a very complex area located within the shaft protective pillar and adjacent to the 50 m wide and steeply inclined fault zone at a depth of 850 m. In addition, 10 longwalls were extracted below each other over many years in several sloping seams located on the other side of the large sloping fault zone resulting in complex stress fields and large subsidence. The immediate roof above longwall 11 …

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The Influence Of Intra-Seam Coal Character Variation On Outburst Risk Potential, Patrick Booth, Jan Nemcik, Ting Ren Jan 2020

The Influence Of Intra-Seam Coal Character Variation On Outburst Risk Potential, Patrick Booth, Jan Nemcik, Ting Ren

Resource Operators Conference

Effective quantification and management of risk associated with sudden gas release during mining (outburst) is reliant on coal and gas properties measurement bases being representative of the local geological and operational conditions. Contemporary gas emission calculation techniques often inappropriately generalise, or neglect, known site-specific extraction geometry, geological conditions, or heterogeneity and anisotropy within the working seam. Over 5000 coal core gas sample results, obtained from two Southern Sydney Basin Bulli Seam underground coal mines, plus coal samples collected from multiple locations at one studied mine, have been analysed in various geospatial and mining process-based context. Analysis has focused on the …

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An Improved Technique For Monitoring Explosibility Of Gases, David Cliff Jan 2020

An Improved Technique For Monitoring Explosibility Of Gases, David Cliff

Resource Operators Conference

Monitoring the potential for explosion in an underground coal mine traditionally centres on using the Coward Triangle, the Hughes Raybould Diagram, the USM explosibility diagram or the Ellicott diagram. None of these allow for analytical trending over time, it is difficult to determine rates of change of gas atmospheres using these techniques and thus predict if and when an atmosphere may become explosive. The Ellicott X Y diagram was an attempt to overcome this, This diagram suffers from the lack of bounds and the absence of an easy way to link the values to the limits of reality eg, fresh …

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Oxygen Deficiency In Graham's Ratio Evaluation, Snezana Bajic, Sean Muller, Mladen Gido Jan 2020

Oxygen Deficiency In Graham's Ratio Evaluation, Snezana Bajic, Sean Muller, Mladen Gido

Resource Operators Conference

There are a number of indicators used to determine the level of coal oxidation in underground coal mines. The common indicator Graham’s ratio is the amount of carbon monoxide produced in proportion to the amount of oxygen consumed by the coal. The more carbon monoxide produced relative to the oxygen consumed (oxygen deficiency), the greater the intensity of the coal’s reaction. Graham’s ratio is often used as a trigger for Trigger Action Response Plans (TARPs) for the management of spontaneous combustion. This emphasises the importance of accurate measurement of oxygen deficiency and ability to successfully determine the status of underground …

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Recent Case Studies Using The Remote Rocsil® Foam Plug System, Neil Alston, Jean-Luc Schmitter, Andrew Alcott, Russell Fry Jan 2020

Recent Case Studies Using The Remote Rocsil® Foam Plug System, Neil Alston, Jean-Luc Schmitter, Andrew Alcott, Russell Fry

Resource Operators Conference

ROCSIL® FOAM is a versatile product that has been successfully used to rapidly seal mines or critical areas of the mine directly in-seam or remotely via boreholes or shafts. The product is chemically stable, fire resistant, fast setting, has high expansion and excellent self-supporting characteristics making it an ideal product for these types of applications. It can also be used on sloping ground and with mine services such as conveyor structure or pipes remaining in-situ to form effective plug seals. For remote sealing, special mixing heads are designed to effectively deliver the product into mine roadways or shafts without the …

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Self-Heating Hazard Investigation Of Conveyor Belt Rubber Fines, Basil Beamish, Jan Theiler Jan 2020

Self-Heating Hazard Investigation Of Conveyor Belt Rubber Fines, Basil Beamish, Jan Theiler

Resource Operators Conference

Conveyor belt fires have often been attributed to the heating of accumulated coal fines beneath the belt structure. However, could it be possible that conveyor belt rubber fines produced from friction of the belt in contact with defective rollers or other parts of the belt structure are a self-heating hazard source? The United Kingdom Health and Safety Executive issued a briefing note in December 2012 on the spontaneous heating of piled tyre shred and rubber crumb. This contained information on laboratory experiments that show rubber crumb and tyre shred are more susceptible to self-heating than cellulosic materials (like hay and …

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Fibre Reinforcement Shotcrete In Coal, Barry Sturgeon Jan 2020

Fibre Reinforcement Shotcrete In Coal, Barry Sturgeon

Resource Operators Conference

Fibrecrete Reinforced Shotcrete (FRS), a cement-based mixture pneumatically applied at a high velocity onto coal surfaces. The material component of shotcrete is essentially cement and fly ash blend in a mixed powder form combined with sand, gravel and water. This wet process of shotcrete application is unique to coal, but has been used in the civil industry and hard rock mines for many years. This process allows a good compaction of applied ground support liner that allows penetration into the strata giving a bonded liner with stability, compared to cast-in-place concrete. The advantages of the shotcrete process are related to …

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Health Monitoring Of Mining Conveyor Belts, Shuvashis Dey, Omar Salim, Hossein Masoumi, Nemai Karmakar Jan 2020

Health Monitoring Of Mining Conveyor Belts, Shuvashis Dey, Omar Salim, Hossein Masoumi, Nemai Karmakar

Resource Operators Conference

The paper presents a new methodology for monitoring health conditions of mining conveyor belts using Radio Frequency Identification (RFID) based sensors. The existing monitoring technique is based on simple visual inspections which is quite labor intensive and do not provide accurate health condition of the conveyor belt. The new methodology based on UHF chipped and chipless RFID sensors provides highly sophisticated real-time monitoring schemes for different conveyor belt health parameters such as cracks. When combined with machine learning algorithm-based approach, the proposed technique can detect and predict wear and tear over the entire belt. Simulation results show that the proposed …

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Safety Aspects Of Disposal Of A Mine And Abandoned Underground Workings And Risks Resulting From Mine Disposal, Radovan Kukutsch, Petr Waclawik, Jan Nemcik, Libin Gong Jan 2020

Safety Aspects Of Disposal Of A Mine And Abandoned Underground Workings And Risks Resulting From Mine Disposal, Radovan Kukutsch, Petr Waclawik, Jan Nemcik, Libin Gong

Resource Operators Conference

Since time immemorial, mining has been an inseparable part of human history. Generations of our ancestors drove and excavated mining workings to enable them find and exploit useful minerals from the ground. Shafts, drifts and corridors created in this way, however, had always limited service life; their significance and purpose mostly expired as soon as the available reserves in the deposit were exhausted. Unused workings were then often abandoned without having been disposed and safeguarded properly. For mining companies, namely, these activities represented and still represent spending of substantial financial resources with zero economic effect. This always relied exclusively on …

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Police Officer Trauma In Rural Minnesota: A Narrative Study, John J. Littlewolf Jan 2020

Police Officer Trauma In Rural Minnesota: A Narrative Study, John J. Littlewolf

Antioch University Full-Text Dissertations & Theses

We call on police officers to respond to all of society’s tragedies. Whether in our metropolitan areas or our rural communities, law enforcement will respond when called upon. The culture of law enforcement is laden with traits of masculinity. These cultural traits can inhibit the processing of traumatic experiences in the individual. While the nature of law enforcement has remained the same, our scientific knowledge regarding trauma has grown. Trauma has a biological impact which can manifest as stress symptomology or PTSD. Our systematic response to trauma in law enforcement has not kept pace with the body of knowledge on …

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Walter S. Davis, Angel Sloss-Prigden, Fletcher F. Moon Jan 2020

Walter S. Davis, Angel Sloss-Prigden, Fletcher F. Moon

Walter S. Davis Biography

No abstract provided.

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Collective History Of Tennessee State University's Building Programs, Vallie Pursley Jan 2020

Collective History Of Tennessee State University's Building Programs, Vallie Pursley

History of Tennessee State University Building Programs

No abstract provided.

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The Ivy Vine October 2020 - Vol. 3 No. 10, Alpha Kappa Alpha Sorority, Inc. Alpha Delta Omega Chapter, Nashville, Tn Jan 2020

The Ivy Vine October 2020 - Vol. 3 No. 10, Alpha Kappa Alpha Sorority, Inc. Alpha Delta Omega Chapter, Nashville, Tn

Alpha Delta Omega Chapter 2020 Newsletters

No abstract provided.

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James A. Hefner, Chris Langer Jan 2020

James A. Hefner, Chris Langer

James A. Hefner Biography

No abstract provided.

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Ramerican Political Science Review (Vol. 5, 2020) Jan 2020

Ramerican Political Science Review (Vol. 5, 2020)

Ramerican Political Science Review

Letter from the Department of Political Science -- Analyzing the Accuracy of Early Warning Systems in the Field of Modern Genocide and Suggested Changes: A Comparative Case Study of Myanmar, Rwanda, and Darfur / Jhanys Gardner -- The Chicken Game and the 1958 Taiwan Strait Crisis / Zhuoran Li -- The Impact of VP Nominees: An Overview of the 2016 U.S. Presidential Election / W.P. Jackson Krug -- The FMLN and FARC as Diverging Models of Post-Conflict Integration / Adam Hales -- Censorship and Control in the PRC / Robert Johnson -- Perpetual Neglect: An insight into the implications of …

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Historical Trends In Air Temperature, Precipitation, And Runoff Of A Plateau Inland River Watershed In North China, Along Zhang, Ruizhong Gao, Xixi Wang, Tingxi Liu, Lijing Fang Jan 2020

Historical Trends In Air Temperature, Precipitation, And Runoff Of A Plateau Inland River Watershed In North China, Along Zhang, Ruizhong Gao, Xixi Wang, Tingxi Liu, Lijing Fang

Civil & Environmental Engineering Faculty Publications

Understanding historical trends in temperature, precipitation, and runoff is important but incomplete for developing adaptive measures to climate change to sustain fragile ecosystems in cold and arid regions, including the Balagaer River watershed on the Mongolian Plateau of northeast China. The objective of this study was to detect such trends in this watershed from 1959 to 2017. The detection was accomplished using a Mann-Kendall sudden change approach at annual and seasonal time scales. The results indicated that the abrupt changes in temperature preceded that in either runoff or precipitation; these abrupt changes occurred between 1970 and 2004. Significant (α = …

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Influence Of Bracing On Buckling Strength Of Pultruded Glass Fiber Reinforced Polymer Frames, Mojtaba B. Sirjani, Zia Razzaq Jan 2020

Influence Of Bracing On Buckling Strength Of Pultruded Glass Fiber Reinforced Polymer Frames, Mojtaba B. Sirjani, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

A numerical study of the influence of structural bracing on the buckling strength of pultruded Glass Fiber Reinforced Polymer (GFRP) frames is presented. Although the influence of bracing on frames made from other materials such as steel have been studied in the past, this paper investigates the performance of pultruded GFRP portal frames with pinned or fixed column bases. Each frame is constructed with pultruded GFRP I-section members. The influence of I-section column major and minor axis orientation is also investigated. The results demonstrate the practical significance of bracing pultruded GFRP frames. The results show that the buckling loads for …

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Nonhydrostatic Modeling Of Flow Interactions With Highly Flexible Vegetation, Navid Tahvildari, Ramin Familkhalili, Gangfeng Ma Jan 2020

Nonhydrostatic Modeling Of Flow Interactions With Highly Flexible Vegetation, Navid Tahvildari, Ramin Familkhalili, Gangfeng Ma

Civil & Environmental Engineering Faculty Publications

Improving our understanding of the interactions between gravity waves, currents, and coastal vegetation, which are nonlinear in nature, enables coastal engineers and managers to better estimate hydrodynamic forces on coastal infrastructure and utilize natural elements to mitigate their impacts. Aquatic vegetation is ubiquitous in coastal waters and it is well-known that flow loses energy over vegetation. Computational modeling of wave-vegetation interaction has been the subject of numerous recent studies and many improvements have been achieved in reducing limitations applied on wave and vegetation behavior in these models. Mechanisms for highly flexible vegetation have been incorporated in a Boussinesq-type model and …

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Lateral-Torsional Buckling Strength Of Two-Span Glass Fiber Reinforced Polymer Beams, Mojtaba B. Sirjani, Zia Razzaq Jan 2020

Lateral-Torsional Buckling Strength Of Two-Span Glass Fiber Reinforced Polymer Beams, Mojtaba B. Sirjani, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents the outcome of a study of two-span glass fiber reinforced polymer (GFRP) I-section beams susceptible to lateral-torsional buckling when subjected to gradually increasing concentrated vertical load(s) in the presence of two different types of lateral bracing schemes. It is found that loading one span results in a smaller buckling load as compared with the cases with loading in both spans regardless of the type of bracing scheme used. Also, the study shows that the addition of midspan braces for the GFRP beams results in up to 5.5 times increase in the buckling load capacity.

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