Early Age Mechanical Behavior And Stiffness Development Of Cemented Paste Backfill With Sand
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Fatigue Mechanical Behaviors Of Rock Backfill Composites Laboratory Study
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Author : Yu Wang
language : en
Publisher: Scientific Research Publishing, Inc. USA
Release Date : 2024-07-18
Fatigue Mechanical Behaviors Of Rock Backfill Composites Laboratory Study written by Yu Wang and has been published by Scientific Research Publishing, Inc. USA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-07-18 with Antiques & Collectibles categories.
This book is intended as a reference book for advanced graduate students and re-search engineers in rock mechanics related to mining engineering. The cemented tailings backfill (CTB) technique is widely used in deep underground mining, since this tech-nique is effective to support surrounding rock, control rockburst, reduce ground sub-sistence, and reduce surface disposal of tailings. Plenty of investigations have been attempted to experimentally or numerically evaluate the strength of CTB with different components (e.g., mixture of cement, tailings, fly ash, blast furnace slag, etc.) to ensure the geological stability when extracting adjacent stopes. After extracting ore from stopes, CTB is filled in the gob, stress redistribution occurs in the backfill stope and surrounding rocks. Due to the elasticity mismatch of these two kinds of material, differential de-formation occurs and they both resist the overburden pressure and deformation. As a result, the interactions between the surrounding rock and tailing backfill material have significant role in maintaining the long-term stability of mine stopes. Apart from the investigations on the static mechanical behaviors of rock- backfill composited backfill (RBCS) material, the RBCS in the stope are also exposed to disturbed stress (e.g., blast vibration, excavation, earthquake, etc.), and the disturbed stress is usually equivalent to cyclic or fatigue loads. As a result, investigations on rock-backfill interactions subjected to the disturbed stress are critical and significant to maintain the long- term stability of mine stopes.
Early Age Mechanical Behavior And Stiffness Development Of Cemented Paste Backfill With Sand
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Author : Abdullah Abdelaal
language : en
Publisher:
Release Date : 2011
Early Age Mechanical Behavior And Stiffness Development Of Cemented Paste Backfill With Sand written by Abdullah Abdelaal and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
Earthquake Geotechnical Engineering For Protection And Development Of Environment And Constructions
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Author : Francesco Silvestri
language : en
Publisher: CRC Press
Release Date : 2019-07-19
Earthquake Geotechnical Engineering For Protection And Development Of Environment And Constructions written by Francesco Silvestri and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019-07-19 with Technology & Engineering categories.
Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions contains invited, keynote and theme lectures and regular papers presented at the 7th International Conference on Earthquake Geotechnical Engineering (Rome, Italy, 17-20 June 2019. The contributions deal with recent developments and advancements as well as case histories, field monitoring, experimental characterization, physical and analytical modelling, and applications related to the variety of environmental phenomena induced by earthquakes in soils and their effects on engineered systems interacting with them. The book is divided in the sections below: Invited papers Keynote papers Theme lectures Special Session on Large Scale Testing Special Session on Liquefact Projects Special Session on Lessons learned from recent earthquakes Special Session on the Central Italy earthquake Regular papers Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions provides a significant up-to-date collection of recent experiences and developments, and aims at engineers, geologists and seismologists, consultants, public and private contractors, local national and international authorities, and to all those involved in research and practice related to Earthquake Geotechnical Engineering.
Early Age Mechanical Behavior And Stiffness Development Of Cemented Paste Backfill With Sand
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Author : Abdullah Muhammad Galaa Muhammad Idris Abdelaal
language : en
Publisher:
Release Date : 2011
Early Age Mechanical Behavior And Stiffness Development Of Cemented Paste Backfill With Sand written by Abdullah Muhammad Galaa Muhammad Idris Abdelaal and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
Rapid delivery of backfill to support underground openings attracted many mines to adopt paste backfilling methods. As a precaution to prevent liquefaction and to improve the mechanical performance of backfills, a small portion of a binder is added to the paste to form the cemented paste backfill (CPB). Recently, adding sand to mine tailings (MT) in CPB mixes has attracted attention since it enhances the flow and mechanical characteristics of the pastefill. This thesis investigates the effects of adding sand to CPB on the undrained mechanical behavior of the mixture (CPBS) under monotonic and cyclic loads. Liquefaction investigations took place at the earliest practically possible age. Beyond this age, the present research focused on characterizing the evolution of stiffness and obtaining the values of the stiffness parameters that could be useful for designing and modeling backfilling systems.The evolution of effective stiffness parameters for two CPB-sand mixtures was monitored in a non-destructive triaxial test for five days. Self-desiccation was found to not be influential on the development of early age stiffness. Moreover, a framework is suggested to predict the undrained stiffness at degrees of saturation representative of the field. The credibility of the proposed test in providing stiffness parameters at representative strain levels of the field was verified.The liquefaction investigation involved monotonic compression and extension triaxial tests. Neither flow nor temporary liquefaction was observed for all cemented and uncemented specimens under monotonic compression, while temporary liquefaction was observed for all specimens under monotonic extension. The addition of binder and sand to MT was found to slightly strengthen the pastefill in compression while weakening it in extension. Under cyclic loading, the addition of sand negatively impacted the cyclic resistance. However, binder was found to be more effective in the presence of sand. All specimens exhibited a cyclic mobility type of response.
Advances In Characterization And Analysis Of Expansive Soils And Rocks
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Author : Laureano R. Hoyos
language : en
Publisher: Springer
Release Date : 2017-07-11
Advances In Characterization And Analysis Of Expansive Soils And Rocks written by Laureano R. Hoyos and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-07-11 with Science categories.
This volume includes a collection of technical papers covering two important research topics in geotechnical engineering: (1) the behavior and treatment of expansive soils, and (2) the characterization of rock properties. The twelve studies on expansive soils include investigations into novel stabilization techniques for expansive soils using different admixtures or mechanical consolidation techniques, as well as new experimental approaches to evaluate the behavior of expansive soils. They also include an evaluation of wetting boundary conditions on the volume change of expansive soils, as well as the role of hydrologic boundary conditions in arid climates. The four studies on rock properties include thermo-hydro-mechanical behavior of gypsum rock, role of rock strength in blastability, indirect methods to estimate rock strength, and variations in isotope distributions in Permian rocks. The two broad themes in this collection, as summarized above, are representative of local challenges facing geotechnical engineers in the Middle East, but their contributions can also be extended to other regions of the world. This volume is part of the proceedings of the 1st GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2017.
A Critical State Approach To The Mechanical Behavior Of Early Age Cemented Paste Backfill
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Author : Amin B. Ghorbanpour
language : en
Publisher:
Release Date : 2021
A Critical State Approach To The Mechanical Behavior Of Early Age Cemented Paste Backfill written by Amin B. Ghorbanpour and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with Controlled low-strength materials categories.
Microscale Analysis Of Cemented Paste Backfill Microform
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Author : Dragana Simon
language : en
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
Release Date : 2005
Microscale Analysis Of Cemented Paste Backfill Microform written by Dragana Simon and has been published by Library and Archives Canada = Bibliothèque et Archives Canada this book supported file pdf, txt, epub, kindle and other format this book has been release on 2005 with categories.
This study shows that wave-based techniques provide insight into some of the factors that affect the behaviour of CPB. Electromagnetic wave-based measurements are sensitive to changes in structure, free water content, bound water content, and ion availability and/or mobility. This research shows that the effective conductivity is a useful parameter to monitor the hydration process, even in low cement content pastes. Shear wave-based measurements are a useful tool to monitor the stiffness evolution in CPB. Apparent yield stress measurements are sensitive to particle-particle interactions and reflect changes in the material's composition, including water content, binder content and type, and chemical additives. All tests show that during the early stages, Portland cement hydration has little effect on the microstructure development, stiffness and flow characteristics of cement-containing pastes. The macroscopic properties of cemented paste backfill (CPB), including fluidity and strength, depend on particle-particle and particle-fluid interactions; thus, it is important to determine the fundamental interactions between the paste constituents to optimize paste design. Specific topics of interest in this study include the effects of paste composition (e.g., binder content and type, and pore fluid chemistry) on the microstructure development, and electromagnetic, rheological and mechanical properties (e.g., setting time, unconfined compressive strength and stiffness) with time. The effect of the pore fluid chemistry on the properties of the CPB depends on the type and amount of the additive. In CPB, calcium chloride and sodium chloride accelerate cement hydration and improve the UCS during the first six months of hydration. Conversely, ferric chloride and hydrochloric acid retard the hydration and setting of CPB. The tested superplasticizers retard cement hydration, increase the UCS and lower the apparent yield stress of CPB. A drawback to using the superplasticizers tested in this study is that a high shear stress is required to re-initiate flow in the pastes.
Cemented Paste Backfill
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Author : Yong Wang
language : en
Publisher: Elsevier
Release Date : 2024-05-19
Cemented Paste Backfill written by Yong Wang and has been published by Elsevier this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-05-19 with Science categories.
In view of the demand for the research on the transport resistance characteristics and mechanical properties of CPB under the influence of temperature effect, the book comprehensively describes the studies on rheological and mechanical properties of CPB materials used in underground metal mines. This book covers a wide range of topics, including a new definition of CPB, past participation and flow-induced corrosion of pipeline under the constant temperature condition, multiphysics processes in CPB and the associated consolidation process, the variation of rheological parameters and transport resistance, prediction model for rheological properties, mechanical behavior and properties of CPB and fiber-reinforced CPB, and control technology to reduce the adverse effect of temperature. Therefore, an academic framework for the transport resistance characteristics and mechanical properties under the temperature effect was established in this book. - Investigates rheological properties and multiphysics processes in CPB materials around the world - Looks into systematic studies on pipe transport and mechanical properties of CPB under temperature effects - Focuses mainly on the effect of temperature on paste transport and mechanical properties under the temperature effect, which provides a theoretical basis for safe and efficient filling operation and associated future research in this field - Offer in-depth insights into the evolution of the rheological and mechanical properties of CPB under the effect of temperatures
A Design Procedure For Determining The In Situ Stresses Of Early Age Cemented Paste Backfill
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Author : Ryan Llewellyn Veenstra
language : en
Publisher:
Release Date : 2013
A Design Procedure For Determining The In Situ Stresses Of Early Age Cemented Paste Backfill written by Ryan Llewellyn Veenstra and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
Prediction Of Mechanical Performance Of Cemented Paste Backfill By The Electrical Resistivity Measurement
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Author : Wenbin Xu
language : en
Publisher:
Release Date : 2018
Prediction Of Mechanical Performance Of Cemented Paste Backfill By The Electrical Resistivity Measurement written by Wenbin Xu and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with Concrete categories.
Cemented Paste Backfill (CPB) has become a useful practice in many modern operations around the world. This method is an innovative tailings disposal and underground mine backfilling scheme that returns much of this material to the underground stope field. Thus, it is of great interest for financial and security reasons to fully comprehend the mechanical performance of such underground CPB. Uniaxial compressive strength (UCS) is one of the most commonly used parameters for evaluating the mechanical performance of CPB. Electrical resistivity (ER) measurement, which is a method of nondestructive testing, can also be used to determine the mechanical properties of CPB. This study was undertaken to suggest a nondestructive testing method that would permit prediction of the UCS of a CPB within 90 days. Five CPB samples were prepared at different cement-to-tailing ratios (1/4, 1/6, and 1/8 by weight) and solid content (65 and 70 wt. %), and a curing period of 3-90 days was used for ER measurement. Seventy-five CPB samples were prepared with the same cement content as those used in the pastes for UCS tests cured for 3, 7, 28, 56, and 90 days. The results of the ER measurement show that the ER versus curing periods of 3-90 days first drop to a minimum value and then gradually increase with time. The greater ER values of CPB are reached when the greater cement-to-tailing ratio and solid content is used. A logarithmic relationship is established between the UCS and the ER of CPB at 90 days. It is possible that a nondestructive method could be developed to evaluate the strength of underground CPB based on the obtained logarithmic relationship with ER at 90 days.