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By B. McKevitt, P. Abbasi

The ion exchange process (IX) is applied in the mining industry for the removal of impurities from process streams, treatment of waste solutions prior to disposal and the recovery of valuable metals. Extensive studies have been performed with the goal of modeling of IX for the case of a single metal loading onto iminodiacetic resin in the hydrogen form. However, in a real system, a resin may be saturated by impurities (iron, calcium, magnesium, manganese), which are then displaced by the metal of interest. The present study provides an insight into the Fe2+ loading process onto iminodiacetic ion exchange resin under the infinite solution volume condition. The study involves the measurement of iron loading under a variety of experimental conditions as well as an attempt to model the loading process using the hybrid correlation advanced by McKevitt (2012). The importance of the experimental and modeling work are discussed in the context of resin in pulp recovery of nickel.

Jan 1, 2014

By James J. Scott

"In the two years since their introduction, Friction Rock Stabilizershave replaced40 per cent of the previously used fixtures in the metal and non-metal mines in the United States. The Friction Rock Stabilizer, or ""Split Set "" , is a mechanical rock stabilizing system which uses friction to prevent rock movement . The Split Set is a tapered, rolled, steel tube that is slotted along its length. As it is driven into a drilled hole smaller than its diameter, it compresses, pre-loading the surrounding rock. This paper discusses the uses and acceptance of the friction rock stabilizer in mines in the United States. IntroductionFriction Rock Stabilizers, commonly called Split Set™· Stabilizers, have been under development by the author and Ingersoll-Rand Company since early 1973. Five years of intensive laboratory and field testing led to their introduction to the metal mines in the United States in the fall of 1976. Actual sales started in February of 1977and, to date, over five million units have been marketed to metal mines. The present rate of usage is near 3 V2 million units per year, which is approximately 50070 of all roof fixtures used in the United States metal mining industry,Richard Hoppe, senior editor of Engineering & Mining Journal. , in an article in the February 1979 issue entitled ""Winning the Battle Against Bad Ground"", said: ""In hardrock mining operations in the western U.S., particularly underground uranium mines where exceedingly difficult ground is common, no roof support system has been accepted more quickly than the Split Set friction bolt invented by Dr. James J . Scott and developed by Ingersoll-Rand Co."" This paper describes how Friction Rock Stabilizers function and presents technical data to show the uniqueness of such systems."

Jan 1, 1980

"The successful commissioning and ramp up of the Albion Process™ at the GPM Gold Project relied on the successful scaling up of the process from batch and continuous pilot plant campaigns (Voigt et al., 2015). Critical information about reaction kinetics and residence time, grind size and pulp density were determined at the laboratory scale and successfully applied to the commercial scale. A limitation of small scale testwork, is that some parameters cannot be measured reliably and scaling up is a function of the physical size of the equipment which isn’t possible to test with laboratory scale equipment. Oxygen mass transfer rate is one such parameter since this is a complex interaction of many factors including slurry temperature, solution and slurry chemistry, slurry viscosity, agitator type, dimensions and power, oxygen bubble residence time, oxygen purity, tank geometry and oxygen injection technique. Oxygen generation represents an important operating cost for the Albion Process™. Pivotal to the Albion Process™ operating economically at atmospheric pressure is the capability to efficiently transfer oxygen while utilising as much oxygen injected to the process as possible. To respond to this Glencore Technology developed the HyperSpargeTM supersonic gas injector. This paper compares the HyperSparge™ against other sparging techniques to quantify the benefits of oxygen injection via a supersonic gas jet on scale up of the oxygen mass transfer system. The paper then examines plant survey data from the GPM Gold Project to demonstrate the very high oxygen utilisation that can be achieved with a correctly designed oxygen mass transfer system.INTRODUCTION One of the main challenges in chemical reactor design is the scale-up of processes from the laboratory to industrial scale. Processes which cannot be faithfully simulated with an experiment at the laboratory scale face challenges due to the physical dimensions and complexity of full scale operation. One example of this is the design of oxygen mass transfer systems in atmospheric oxidative leaching circuits such as the Albion Process™. A number of constraints associated with the use of laboratory scale equipment to design full scale circuits are involved in gas mass transfer processes in agitated slurries such as the Albion Process. Chiefly, typical laboratory and pilot size equipment lacks the required volume to provide useful design data without relying on empirical correlations: the specific agitator power input is artificially high, the bubble residence time in the vessel is artificially low, the oxygen partial pressure at the base of the vessel is artificially low and the oxygen delivery method may differ significantly to the industrial process. Further, the dynamic nature of the process introduces additional impacts on gas mass transfer, including the presence of solids, recycle streams and minor elements, plus the variances within the reality of a process plant such as disruptions or variance of feed quality."

Jan 1, 2017

By Scott L. Ewart, William M. Bryden, Donald E. Wakefield

"Osler, Hoskin & Harcourt develops commentaries from time to time on topics of legal interest. These may deal with new legislation, changes or developments in government policy or recent judicial decisions of importance to its clients. The commentaries are, of necessity, general in nature. Because the law which they deal with is often new and untested, it is hard to arrive at precise statements of the way in which the principle s discussed in a commentary might be applied in specific circumstances. When further guidance is needed , consult a solicitor.The purpose of the Bill is to simplify, modernize and standardize the regulation of mineral exploration and development in Ontario. Many of the changes proposed by the Bill are of an administrative nature and move much of the detail with respect to staking, assessment work, prospecting work, surveys, quarry permits and leases contained in the existing Mining Act to the Regulations contemplated under the Bill.The Bill will undergo revision and be re-introduced and therefore it is not the intention of this present article to detail the specific changes contemplated by the Bill; however , its more significant changes are as follows:1. Provision is made for a lifetime prospector's licence with the elimination of annual renewals;2. Perimeter staking of a block o f claims is permitted to reduce the cost of staking;3. Assessment work requirements are expressed in term s of dollars spent rather than days worked;4. Persons doing exploratory work are required to furnish notice to owners of surface rights of intention to perform assessment work;5. Annual work summaries will be available to the industry to lessen duplication in exploration work;6. The option of continuing assessment work rather than applying for a lease is provided;"

Jan 1, 1984

By C. R. Whittemore

PROGRESSIVE industrial organizations have recognized the importance of maintaining an adequate reference library of volumes covering all phases of their particular branch of industry, but it has been the experience of the writer that few engineers know how to use to the best advantage this store of extremely -valuable information which has been accumulated for their service. Nor does the average engineer appreciate the fact that it is only through the current technical literature that he can keep abreast of the rapidly developing fields of engineering. The present-day ramifications of the engineering field are of such wide scope that the human mind is not capable of storing away more than a small fraction of the information available on any particular topie; yet, from time ? to time, such information would prove invaluable. An engineer can know intimately only a small part of his own branch of engineering; but he cannot afford to neglect to take the fullest possible advantage of all that is already known in his own particular field. Technical information may be obtained by one or more of the following methods: (1) by enquiring of the individual who knows; (2) by performing the experimental investigations necessary to ascertain the facts; (3) by consulting the technical literature, where a record may be found of the work of others. This last method is the one we wish to examine. Our main consideration is the question of how to use the library, but first it is necessary to give some attention to the kind of enquiries one takes to the library, and to the nature of the sources of information available.

Jan 1, 1938

By A. J. Sinclair

"Abstract-Geology contributes essential information toward obtaining high-quality resource/reserve estimates. In this context, geology can be considered under the following overlapping topics: regional geology, detailed (deposit) geology, mineralogy, ore deposit models and continuity, with geological mapping being fundamental to all. Each of these topics is considered here in terms of potential contributions to "improved" mineral inventory estimation. Some of the principal conclusions are:1. Regional geological relations must be consistent with deposit geology. It is common that important geological relations are more clearly evident in various regional locales than in highly altered and/or highly deformed mineralized areas containing mineral deposit.2. Detailed geology provides information for a geometric model of a deposit, a model that serves as a basis for mine planning. It is important to distinguish fact from interpretation in such models. Substantial effort is required to characterize the geometric margins of a deposit and the relation of these margins to the simplistic geometric form that normally emerges as an interpretation.3. Mineralogical studies relate to many aspects of deposit evaluation including abundance of ore and deleterious minerals, spatial distribution of ore and deleterious minerals, grain size characteristics of important minerals, mill design, etc.4. Ore deposit models contribute substantially to confidence in developing a three-dimensional geometric model of a deposit for mine planning. Specifically, they are a basis on which to develop rules for interpolation and extrapolation of ore, and they contribute to recognition of domains, each with its own characteristic continuity and margin character.5. Continuity is dependent on mineralization style and may be controlled structurally and/or chemically. It is important to distinguish geological continuity and value continuity. A wide range of classical geological methods are useful in examining geological continuity; value continuity is best viewed as a statistical characteristic that is quantified by any of several measures of autocorrelation."

Jan 1, 1998

By G. Landry

"IntroductionThe Cape Breton Development Corporation (CBDC) is constantly searching for new technologies that will enhance the marketability of its coal. One technology which shows promise in utilizing Cape Breton coal while at the same time addressing the traditional problem of high sulphur inherent in the Sydney coalfield, is coal-water fuel (CWF).The CWF process incorporates a physical change of coal by grinding it to a flour-like consistency and then mixing additives with it to make a fine coal slurry. The result is a liquid dispersion of fine coal particles that looks like oil, stores and flows like oil but burns like coal. The equipment used in the CWF process is standard mineral processing equipment but application of the equipment to manufacture a specific coal particle size and the specified additives used in the mixing make it a unique technology.The product, which CBDC calls Carbofuel, consists of 70% coal, 29.5% water and 0.5% chemical additives. The key properties of the product are: (I) high solids loading, (2) medium viscosity levels, (3) stability against sedimentation, and (4) good atomization behaviour. Carbofuel specifications are presented in Table I. Carbofuel ProductionThe production of Carbofuel is based on the controlled processing of coal. This involves wet grinding of the coal to a specified fine size (-250 um), cleaning this fine product to remove mineral impurities and formulating (with chemical additives) a finalproduct from the cleaned coal. The flow diagram in Figure 1 indicates the processing circuit for Carbofuel production.CBDC operates a 7-tonne-per-hour continuous production plant complete with state-of-the-art control, full laboratory services, product storage and loadout facilities. The plant has operated since 1983 and has produced over 12000 tonnes for several major demonstrations. The plant is shown in Figure 2."

Jan 1, 1987

By E. P. Wiechrnann, C. M. Castro, G. A. Vidal, F. A. Muñoz

Different authors and publications indicate that Optibar Segmented Intercell Bars cause a remarkable distortion in the distribution of the current in a cell group. However, these results were based in inaccurate computer based models and do not represent the technology. During the last trimester of 2010, a 92 cells circuit from Barrick Zaldívar EW plant was implemented with Optibar Segmented Intercell Bars. The technology was incorporated progressively without disrupting the plant production. Depending on operational conditions, this led to a 2 to 4% current efficiency increase and 3 to 5% specific energy consumption reduction. By October 2011, 40,000 tons of copper will be produced with the technology.

Jan 1, 2011

By Kurt Tischler

This paper presents the field experience of Siemens with regard to Gearless Drives in the mining industry ? We consider the elapsed production hours of Siemens Gearless Drives to be extensive enough to provide a reliable estimation of availability calculated on the basis of data representing repair time, downtime, and operating time. The users of Siemens Gearless Drives confirm an availability of more than 98% after exclusion of some major issues. The paper addresses all of these major issues of Siemens Gearless Drives, describes successfully applied corrective measures, explains the influences on the design of the drives, and lists the downtimes associated with each of these issues.

Jan 1, 2012

By Robert J. Shank

This paper describes the Federal Government assistance available for northern mining development. The paper commences with a discussion of why the Federal Government should give assistance to northern mining development. It then uses a hypothetical case of a company which has a property it wants to develop to list the sectors within the . Federal Government that would have to be consulted in order to obtain federal financial assistance. The paper also outlines the type of information a company must be willing to provide the government in order to qualify for such assistance.

Jan 1, 1978

By K. Bullock, M. Levesque, G. Lyle, D. L. Millar

ABSTRACT The options for reducing the carbon footprint of energy use in mining fall into three categories of activity: i) reducing demand, ii) improving energy utilization, and iii) adopting low carbon energy technologies. In addition to the environmental imperative, the economic case for these activities gains higher priority as the prices of electricity, gas, and liquid fuels increase. Low-carbon, energy-saving technology options that are available to mining industry companies lead to projects with return rates that must compete alongside other capital-intensive projects considered by mining company boards. Energy projects frequently involve longer payback periods and lower rates of return than those of competing bids for capital, such as new mineral property developments. For energy services companies that specialize in the financing, construction, efficient operation, and maintenance of energy projects, the same returns and payback periods can be considered acceptable or even attractive.

Jan 1, 2012

By Egbert Burchardt

The challenge of "ore bodies getting steadily harder and lower in grade" was brought to light during the first oil crisis in the 70's. Shortly afterwards, HPGRs appeared on the scene with the promise of saving energy. This combined with developments in wear protection for the rolls ushered in a period of trade-off studies that considered the HPGR as an option to improve project economics or to even make projects feasible at all. Since then, applications of HPGRs at Cerro Verde (Freeport), PTFI Grasberg (Freeport), Mogalakwena (Anglo Platinum), Tarkwa (Goldfields), Boddington (Newmont), Penasquito (Goldcorp), and others have contributed to the creation of a formidable basket of operating experience. Collected through years of successful operation, this information has been used to validate design criteria, scale-up factors and establishing a clearer picture of what "to do" and what "not to do". This paper compares results from various mining operations using HPGRs in their processing plants. Some of the lessons learnt in different operating environments are reviewed in order to support proper implementation and operation of HPGR's. Some of the development programs that have been initiated to improve wear life of the tyres and to reduce overall operating costs are reviewed. It is timely to summarize today?s experience and analyse its implications for existing and new operations.

Jan 1, 2012

Pillars are used in various forms in underground mining. For several decades pillar design has been an issue in both soft and hard rock underground mining. The major use of pillars is in room-and-pillar type mining. Pillars are critical structures in the production levels of block cave mines. With most mines leaning towards the use of block caving for ore extraction today, pillar design has become even more important. Empirical pillar design is popular. The use of numerical modeling is becoming more common in the design of underground mine pillars. A critical review of both the empirical and numerical modeling approaches to the design of underground mine pillars reveal some fundamental flaws. In general, pillar design approaches often assume the pillars are vertical, and are subjected to pure compression. Pillar failure criteria are then based on this assumption. Most papers on numerical modeling for pillar stability assessment use vertical pillars. This paper shows that where pillars are not subjected to pure compression the empirical pillar design approaches are inadequate, and that when using numerical models for the assessment of pillar performance, more care is needed in the determination of the average pillar stresses. The practice of relating field scale pillar strength to laboratory scale intact rock strength determined from conventional laboratory compression tests in empirical design equations is misleading when pillars are inclined or subjected to compressive and shear stresses. New data is added to the hard rock empirical pillar stability chart, and it is shown that it is misleading to conclude that failure of pillars with width to height ratios greater than 2.3 should not be anticipated. New empirical pillar design charts are presented for pillars at various degrees of inclination for different ko-ratios.

Aug 1, 2013

By R. H. Watson

A paper read by J. A. H. Church before the Northern Alberta Branch last February described a method of working thick inclined coal-seams from the dip upwards, with the view to preventing fire risk by using water for the stowage of waste workings, and extinguishing a conflagration should such break out, was favorably received; but there was some doubt as to the cost of such a method, as it involves a retreating system, which might prove too expensive for practical adoption. Let us consider a typical leasehold such as we are familiar with in the Rocky Mountains. The leasehold is crossed at one end by a mountain river, which is cut by the outcrop of a seam of coal, 30 feet in thickness, pitching as shown on the drawing herewith, which also shows the general line of the outcrop in elevation through the leasehold, which is two and a half miles long and contains 1,500 acres. The average lift is about 600 feet above river level and drilling has proved that the coalseam can be tapped at a depth of 1,500 feet, 2,000 feet down the pitch from the outcrop in the river, all as shown in the illustration, which is typical enough of our mountain conditions to serve the purposes of comparison of methods. We take up the leasehold and invest $30,000 to pay for drilling and prospecting; $30,000 more for the price of the lease to locator or holder, and say $100,000 to pay for a railway spur (it might cost twice this sum, but we are only comparing two methods in the same location) and "now we are ready to consider equipment and the cost of development.

Jan 1, 1924

By J. van Deventer

Volatile gold prices in the face of rising costs for mining and refining is causing the mines to look for new ways to reduce costs and increase recoveries. This task is complicated by the fact that the gold in hereto unexploited reserves is associated with increasingly complex ores - either preg-robbing, refractory, associated with high concentrations of copper, or all of the above. Ion exchange resins can play a significant role in this quest for improvement. Although ion exchange resins have been used in Former Soviet Union (FSU) countries for the recovery of gold for many decades, it is still not widely used in the Western World. Synthetically manufactured ion exchange resins can be tailor-made to suit the chemical and mechanical characteristics of a specific application. As such, ion exchange resins can be used in a variety of solution matrices (e.g. cyanide, thiosulphate and acid), and process designs (recovery from clear liquor after solid-liquid separation or directly from the leached pulp). In this paper, a number of applications are discussed along with a review of recent developments in ion exchange technology.

Jan 1, 2014

By Sylvie Lévesque, Cory Hennessey, Daniel Amariei

"In the iron ore industry, fine particles recovery is an important concern in terms of process performance and production costs. Continuous efforts are thus devoted to increase the efficiency in handling these fines.The Reflux Classifier (RC) is a relatively new technology that is mainly used in the coal and industrial minerals industries. The operating principle of this system is based on three mechanisms: hindered settling, autogenous dense medium and lamella settling. A preliminary evaluation of the Reflux Classifier technology for the beneficiation of iron ore fines was formerly done at the pilot scale using a RCTM300 unit. The good results obtained, using iron ore fines from screened spiral stream, made this technology very attractive for the iron industry. However, the high capacity of the RCTM300 unit (1–3 t/h), makes it unsuitable for R&D purposes. Thus, a smaller unit, the RCTM100, was assessed to validate the performances obtained with the RCTM300.This paper summarizes the performances obtained with the RCTM100. The challenges of the scale-down related to the adaptability of this technology to the iron ore industry are also presented. The results are compared to the RCTM300 performances, as well as benchmarked against sink-float tests. The metallurgical results on feed and products issued after the test work with the RCTM100 unit are supported by mineralogical characterization using a Mineral Liberation Analyzer.INTRODUCTIONFine particles recovery by physical separation means is a historical concern (Holland-Batt, 1992; Peukert and Wadenpohl, 2001; Srivastavaa et al., 2001; Majumder et al., 2003). Attempts to improve fine particle recovery at the laboratory, pilot and industrial scales adopting different strategies with traditional equipment or assessing new promising devices such as the MGS (multi-gravity separator), the Kelsey jig, the Yang jig, etc. (Kim, 2002; Goudreau, 2008; Kerr, 2012) have yielded variable success."

Jan 1, 2016

By Cesar H. Oboni

The development of specific risk-based methodologies to guide and prioritize clearing decisions in countries contaminated by Unexploded Ordnance and Land Mines (generically defined as Explosive Remnants of War: ERW) either at country-wide scale or road-network-scale was used in an unexpected way when a large mining company asked Riskope (www.riskope.com) to develop a multi-modal transportation network risk assessment plan, which included ocean going vessels, ports, wharves, railroad, trucking and other modes of transportation. What had been a first-in-the-world attempt in the humanitarian landmine clearing industry turned out to be extremely useful and equally innovative in the extractive corporate world. Instead of a country contaminated by man-made hazards such as Explosive Remnants of War (ERW) we were now dealing with a very complex multi-modal transportation system afflicted by all sorts of potential hazards from quakes to climate change, sabotage to labour strikes, and vulnerable infrastructures to potential energy crises. Interestingly enough the method developed to deal with ERW risk based clearing was also capable of solving the transportation risk evaluation problem, after necessary customization. This paper shows how ?out of the box? thinking and industry cross dissemination can bring significant evolution and a competitive edge even to unexpected areas of the world-wide mining industry. The results of the logistic system risk assessment shed new light on the management of the system, changed the way insurance coverage was purchased, and led to significant potential cost reductions in a period of global recession.

May 1, 2010

By José L. Carvalho

"Time-dependent swelling deformation of several shaley rock formations in Ontario is a wellknown phenomenon. In shales and mudstones with a higher salt concentration in the pore fluid than the ambient fluid, the outward gradient generates an osmotic pressure which acts as the driving force for swelling. The swelling phenomenon appears to be related to ion exchange between the rock porewater and the surrounding water.The swelling potential is expressed as the percent swelling strain that occurs per log cycle of time, in either the vertical (perpendicular to bedding) or horizontal (parallel to bedding) directions. In addition, the swelling potential is also noted to be stress dependent. In practice, therefore, the conditions required for swelling are (i) the accessibility to water, and (ii) an outward salt concentration gradient from pore fluid of the rock to the ambient fluid. The relief of in-situ rock stress during excavation serves an initiating mechanism (Lo and Micic, 2010).INTRODUCTIONTime-dependent swelling deformation of several shaley rock formations in Ontario is a well-known phenomenon. In shales and mudstones with a higher salt concentration in the pore fluid than the ambient fluid, the outward gradient generates an osmotic pressure which acts as the driving force for swelling. Swelling is also controlled by the inter-particle bonding; if the bond strength exceeds the osmotic pressure, swelling will not occur, and vice-versa. The bond strength can be reflected by the calcite content which forms cementation bond between rock particles."

Jan 1, 2015

By Mi, Dong Liang, Jingyuan Bai, Victor Zhou, Xujun

Squirrel cage induction motors are the mostly used motors at present. Currently, the rotors of the squirrel cage induction motors are produced by aluminum die casting technique with the advantages of low cost of rotors. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size. Considering the huge quantity of motors, the die casting process is the best solution to produce copper rotor with economic cost. Because of the characteristics of copper, it is difficult to produce copper rotors by casting similar to that done in aluminum rotors. In order to improve the die casting quality of copper rotor, a new tooling structure was developed and the casting process of copper rotor was simulated and analyzed by Any-casting software. The filling process, solidification process, inner gas distribution and residual melt modulus were analyzed. It was found that the design of symmetrical runner and inner runner on both sides was helpful to reduce the impact of molten copper to the cavity surface during the filling process. The use of Slag traps array can reduce die casting defects inside the end rings. That will be helpful to improve the rotor quality. INTRODUCTION Squirrel-cage AC induction motors are most widely used in the world. In 2017, the total installed capacity of AC motors in China has reached more than 1.2 billion kW, and the annual power consumption accounts for about 60% of the total national electricity consumption. To improve the efficiency of squirrel-cage motor will be helpful to energy conservation and environment protection. There are several ways to improve efficiency of induction motors, using copper rotor is one of the most effective solutions. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size.

Jan 1, 2019

By R. Kumar, A. K. Verma

"In this paper, an anisotropic shear behavior of rock joints is investigated under constant normal load condition (CNL). The natural rock joint roughness is transferred to artificial rock samples using room temperature vulcanizing (RTV) silicon rubber. Artificial cylindrical rock joint samples (90 mm diameter and 50 mm height) are made by mixture of cement, sand, and water in the ratio of 1:1.5:0.45 (by weight). Direct shear tests are conducted on these samples in twelve directions at 30º apart at four different normal stresses (250kPa, 500kPa, 1000kPa, and 1500kPa). Thus, 48 samples are tested in laboratory. Test results shows that the peak shear strength (?) of rock joints is anisotropic in nature due to change in morphological features in particular shearing direction. Joint roughness coefficient (JRC) is determined in each shearing direction by trial and error method using Barton’s model (1973). Further, cohesion ( c) and angle of friction ( ? )of joint surface in each direction is determined. Finally, a relationship between angle of friction ( ? ) and joint roughness coefficient (JRC) is developed. Experimental shear strength and Barton’s shear strength is compared and it is found that effect of anisotropic decreases with increasing normal stress. INTRODUCTIONRock mass is generally composed of discontinuity which refers collectively to joints, faults, bedding plane and folds etc. ISRM (1978) defined joint as a line of break of geological origin along which there is no visible displacement. Joint is three dimensional discontinuity which composed of two matched/mismatched surfaces. The presence of joints in rock mass plays an important role to define its overall shear strength, deformability behavior, in-situ stresses and hydro-geological properties. The shear strength of rock joints is important in the design of near surface/ deep geotechnical works (mining excavation, dam foundation, power plants, underground caverns, and slopes).In last 40 years, many constitutive models are developed to predict shear strength of rock joints under CNL conditions (Patton 1966; Landanyi and Archambault 1969; Barton 1973; Goodman 1976; Barton and Choubey 1977; Plesha 1987; Desai ad Fishman 1991; Amadei and Saeb 1992; Maksimovic 1992; Wibowo et al. 1993; Huang et al. 1993; Amadei et al. 1998; Indraratna 2000; Homand et al. 2001; Wang et. al. 2003; Samadhiya et. al. 2008; Asadollahi and Tonon 2010; Ghazvinian et al. 2012). These constitutive models have limitations to predict shear strength of rock joints in one direction. Till date, among all constitutive models, Barton (1973) model is widely used in practice due its simplicity. It includes parameters such as joint roughness and joint compressive strength (JCS) to quantify joint surfaces."

Jan 1, 2015