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By J. Ivon Graham, T. D. Jones

This paper presents methods in use in British coal-mines for the suppression of dust. While the effect of present-day treatment will not be apparent for several years, in pits in South Wales, concentrations as high as 50 gm./1,000 cu. ft. were some years ago fairly common in various operations at or near the coal-face, with an average concentration of 20 gm./1,000 cu. ft. Now the average concentration in what were previously dusty pits is probably not greater than 3 gm./1,000 cu. ft.Nevertheless, every effort must be made to improve conditions still further. In South Wales it is claimed that 99% of the coal-faces requiring treatment have been dealt with either by wet cutting, infusion, or hand-spraying. The extent of the treatment by these methods can be gauged by the fact that the total length of coal-faces now being treated by water infusion in Cardiff and Swansea areas is about 33,000 yds., by wet cutting 25,000 yds., and by hand-spraying nearly 14,000 yds. The influence of methods of mining upon dust production is only mentioned very briefly in this review, and there is no doubt that much more is to be learned concerning this aspect. It can be stated, however, that good mining practice is essential to prevent unnecessary dust production, and the problem of dust in mines will be solved only by the closest co-operation between mine managers, workmen, and scientists.

Jan 1, 1947

Sequential and evolutionary changes through time are recognizable in many, perhaps most major families of ore deposits and their geological environments. These changes are additional useful indicators of the evolutionary history of the earth and its tectonic processes. They are important in mineral exploration because they involve consideration of time as a fourth dimension, thereby indicating the most favorable ages, rather than types of rock for investigation. Many of the changes are analogous to those recognized in faunal evolution. Some primitive, unspecialized types of ore deposits occur nearly unchanged through rocks of widely differing age. Others diversify into several, more specialized variants, whereas still others become extinct. The place of these is taken by new, younger types, some of which undergo sudden proliferations and later diversifications of their own. In Archean greenstone belts irrlportant iron, nickel, gold, and base metal deposits occur co-regionally, but in different stratigraphic positions in the same, thick volcano-sedimentary successions. Here their close temporal and spatial associations suggest common genetic exhalative hydrothermal processes. The massive base metal sulfide family of ore deposits provides an excellent example of evolutionary changes, exhibiting distinct variations through both time and space. Deposits belonging to this family span the entire range of time, occurring in rocks of ancient Archean to Recent age, and specific types within the family also span the entire range of spatial environments from ensimatic to ensialic. Moreover there are possible evolutionary metallogenic links between certain types of massive base metal sulfide deposits and other important base metal ores, noteably Mississippi Valley-type and porphyry copper deposits.

Jan 1, 2013

By John A. Herbst, Xiangjun Qiu

"Prediction of wear on a microscale level in mineral processing equipment turns out to be a challenging undertaking. This is particularly true for cases in which the objective is to use such predictions for wear parts design. The key to obtaining such predictions has turned out to be the use of physics based models along with phenomenological constitutive equations. In this paper, two components of the HFS tool set, one for particles (DEM) and one for slurry (MPF), are used for modeling. These tools are applied to the simulation of wear of SAG/AG shell lifters/plates and wear in slurry pumps. In each case wear predictions are validated with plant measurements.INTRODUCTIONHigh Fidelity Simulation (HFS) has emerged as an important tool set for mineral processing plant equipment design and optimization (Herbst and Potapov, 2003; Herbst and Nordell, 2002; Herbst and Lichter, 2006). This tool set consists of Discrete Element Modeling (DEM) of particle motion, Multi-Phase Flow (MPF) for liquid motion, discrete grain breakage (DGB) for particle fragmentation and discrete grain liberation (DGL) for mineral liberation (Campbell, Potapov and Tsuji, 1997; Ferzinger and Peric, 1997; Potapov and Campbell, 1996; Herbst and Potapov, 2005).Three sample snapshots of basic HFS illustrating the use of each of the various types of mineral processing equipment are shown below.Figure 1 shows a snapshot of a DEM simulation of ball charge motion in a commercial scale Vertimill. DEM simulation involves simultaneous solution of Newton’s Laws of Motion for 400,000 balls."

Jan 1, 2007

By R. Trammell, O. Eterigho-Ikelegbe, S. O. Bada

In response to the enormous amounts of coal discard generated during coal mining and preparation, the development of an efficient and sustainable strategic use of this resource is essential. Furthermore, the rising urban population over the next decades is confronted with the depletion of quality raw materials for building components. To this end, this study reports new information on the morphology, water absorption, and flexural strength properties of ceramic composites produced from three different coal discards and polysiloxane pre-ceramic polymer (PCP) resin. In addition, test results relating to the continuous operating temperature, chemical resistance, and efflorescence potential of the composites are presented. The results show that the water absorption and flexural strength of the coal composites, up to 1.94% and 36.46 MPa respectively, exceed the requirements for ceramic and clay roof tiles. The continuous operating temperature of composites is found to be more thermally stable than conventional roofing tiles (concrete and ceramic) between ambient temperature and 600°C. In addition, the excellent chemical resistance of the composites (94.43%−99.98%) compared to conventional roofing tiles (67.82%−99.97%) eliminates the need for additional external coatings. The interesting results documented so far suggest that this technique could be used to produce low-temperature application building products such as bricks, panels, roofing tiles, etc. This new recycling technique offers an excellent opportunity to eliminate enormous volumes of coal discard and to advance the circular economy in the coal industry.

Aug 2, 2022

By James D. Noll, Jon A. Hummer, Shawn E. Vanderslice, Aleksandar D. Bugarski, George H. Jr. Schnakenberg, Steven E. Mischler, Larry D. Patts

The National Institute for Occupational Safety and Health designed and conducted a study in an underground metal mine to assess the effects of selected diesel emissions control technologies on the concentrations of diesel particulate matter and gases in underground mine air. The control technologies studied included diesel particulate filter (DPF) systems, filtration system with disposable filter elements, diesel oxidation catalytic converter, and biodiesel blends. Each technology was tested on a mining vehicle operated in an isolated area of an underground mine supplied with fresh air. These isolated zone tests allowed for the operation of vehicles under conditions and over duty cycles that closely mimic actual duty cycles of production equipment. The DPF systems reduced the elemental carbon (EC) concentrations in mine air between 88% and 99%. The same systems reduced total particulate matter (TPM) concentrations in mine air by approximately 75%. The biodiesel blends B20 and B50 caused a reduction in the EC concentrations of 26% and 48%, respectively. Those blends also reduced TPM concentrations by 9% and 24%, respectively. The use of #1 diesel fuel reduced EC concentration by 13% compared to #2 diesel fuel. An increase in nitrogen dioxide concentration of up to two times was seen when platinum-catalyzed DPF systems were tested.

Jan 5, 2006

By F. R. Lee

[WHEN the Bureau of Mines was established in July 1910, one of the problems immediately attacked by the new organization was the development of standard, for the design and testing of electrical equipment that could be used without fear of initiating fires and explosions in underground coal mules. Research and investigation by Bureau personnel, supplemented by the published results of similar work by European mining authorities, led to the establishment of standards or "schedules." which guide manufacturers in the design of many types of electrically operated machines and devices used in. underground coal Mining. By issuing these standards, Bureau personnel establish the requirements to be met by such equipment before it tan be approved by the Bureau of Mines as permissible for use in gassy coal mines. Every 2 years the Bureau of Mines publishes a list of equipment that leas been accepted as approved or permissible during the preceding 2 calendar years. This is done to inform the mining industry of the availability of the latest equipment for safe use underground.]

Jan 1, 1964

By F. R. Lee

When the Bureau of Mines was established in July 1910, one of the problems immediately attacked by the new organization was the development of standard, for the design and testing of electrical equipment that could be used without fear of initiating fires and explosions in underground coal mines. Research and investigation by Bureau personnel, supplemented by the published results of similar work by European mining authorities, led to the establishment of standards or "schedules." which guide manufacturers ill the design of many types of electrically operated machines and devices used in underground coal Mining. By issuing these standards, Bureau personnel establish the requirements to be met by such equipment before it tan be approved by the Bureau of Mines as permissible for use in gassy coal mines. Every 2 years the Bureau of Mines publishes a list of equipment that leas been accepted as approved or permissible during the preceding 2 calendar years. This is done to inform the mining industry of the availability y of the latest equip¬ment for safe use underground.

Jan 1, 1964

By E. R. Lea

The B. M. & S. orebodies, consisting of the No. 6 (Brunswick) and the No. 12 (Anacn Leadridgz, have the distinction of being the first major 1base metal ore deposits to be found in the Province of New Brunswick. They are massive sulphide de-posits consisting of pyrite (pre-dominantly) and base metal sulphides, and they carry values in lead, zinc, copper, and silver. These orebodies are localized within favourable drag fold structures believed to be related in their origin to external forces set up in the area subsequent to the primary regional folding. Both orebodies are characterized by the presence of magnetite 'iron formation' which, in certain 'Portions of each orebody, may be found as relics within the massive sulphides. Studies show the magnetite to be the first metallic mineral within the ore ?zones, followed by pyrite, Sphalerite, galena, and finally chakopyrite. The shape of these massive pyritk orebod:es as well as the distribution of values within them is controlled to a large degree by the ore-ore drag fold structures. A possible relationship is discussed between the basic intrusives in the area ?and the magnetite deposits. It is suggested that a large portion of ?the iron content of the massive suplhedes has been derived from the earlier magnetite. Intermittent movements in the area during the sulphide mineralization are believed to belong to the last stages of deformation in the area. These late movements may have been caused by the intrusion of the granite into the area. The granite may have a genetic relationship to the B. M. & S. orebodies.

Jan 1, 1958

This publication summarizes, for all interested parties, the research, development, and demonstration in-house projets programed by the Bureau of Mines for fiscal year 1980 (October 1, 1979 - September 30, 1980) under its Minerals Health and Safety Research program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1980

By AIME AIME

WHEN "Chief" Buehler in mid-September set out on his official 10,000 mile swing-around-the-circle visiting Local Sections he decided not to tell his audiences how to organize and operate a state geological survey. As the director for 28 years, of the Missouri Bureau of Geology and Mines (which, he concedes, is the best in existence) lie could have done this to good advantage; but he preferred to discuss affairs of the Institute. In 25 speeches made to member and student groups, he dwelt on sonic or all of the following phases of activities. He stressed the vital importance of the Local Sections in providing the opportunity for members to associate under pleasant auspices with others in their profession. The benefits of Institute membership he classified as tangible and intangible. Of the two lie felt that the latter were more important. A man's progress in his profession depends in large measure upon a broad acquaintance and friendship with others. The Institute is incomparably the best medium for meeting fellow engineers. The primary, function of the new enlarged Membership Committee is to obtain a comprehensive list of engineers eligible to be members, always hearing in mind that the standards of membership must not be lowered in any degree. These men are to be invited by individual letter to apply for membership. Whether they become members or not is of less importance; but it is vital that no qualified man should be outside the fold for the reason that membership had never been suggested to him. Dr. Buehler emphasized repeatedly his feeling that the younger man that had never had Institute membership brought specifically to his attention had been cheated:

Jan 1, 1935

By Víctor T. Mejía Campos

El presente texto describe el proceso de remolienda efectuado en el circuito de flotación de bulk en la concentradora Casapalca. Dicho estudio se basa en dos proyectos anteriores, donde se buscó mejorar la molienda inicial con la instalación de un molino de bolas Marcy - 64-1/2 y el uso cuatro ciclones tipo Krebs de lú11 (3 en trabajo permanente y uno de repuesto) y un clasificador tipo Dorr Duplex de 71 x 28-1/2' de 19 rastrilladas por minuto. Dado el éxito obtenido en el primer proyecto, se prosiguió con el segundo. Finalmente, el 6 de octubre entró en operación normal el nuevo circuito de remolienda de las partículas gruesas en el circuito de flotación de bulk donse se comparó los promedios de los resultados metalúrgicos obtenidos en el año 1960, contra los resultados obtenidos en el año 1962 y se evidenció que este proceso mejoró la recuperación, produciendo más toneladas adicionales de concentrados.

Aug 20, 1963

By Richard Crockford

The World Trade Center (WTC) is located on the west side of Manhattan in New York City, approximately 0.5 miles north of Wall Street, and is owned and operated by the Port Authority of New York and New Jersey (PA). As part of the WTC site redevelopment the New York City Transit Authority?s No. 1 subway line which runs through the site below grade, was underpinned so that the soil beneath it could be removed along with the rest of the new east basement excavation. Consequently a scheme comprising micropile installation through and around the existing subway box was designed. The subway had to remain in use throughout save for planned weekend outages to allow a portion of the underpinning to be fitted through or on to the existing structure. At times this involved accessing and drilling from within the subway tunnel under short General Order (GO) Subway shutdown periods. At either end of the subway passage through the WTC site jet grout underpinning was designed to provide support and to complete the excavation and construction of the east basement wall in the areas beneath the subway where it was impossible to install a slurry wall. The jet grout blocks thus formed had to be largely installed around the clock during 53 hour long GO weekend outages and had to overcome severe logistical constraints in and over the tunnel. The jet grout blocks had to provide strengths of at least 500 psi at 3 days and 700 psi at 28 days. The jet grouted soil mass also had to have a level of permeability less than 0.03 feet/day (1 x 10-7 m/s). After an extensive trial program and then production testing it was concluded that the glacial till above the rock proved to be a particularly difficult soil strata to collect test data from and hence the level of observational monitoring was increased to progress the excavation works. Throughout the installation of micropiles and jet grout columns extensive monitoring was in place and prompted a variety of working method changes. The work described in this paper was performed by the Nicholson Construction Company/EE Cruz Joint Venture.

Jan 1, 2008

By Robert G. Bottge

Hard rock mining has grown in importance in the Yukon Territory during the last 10 years while Alaskan hard rock mining has declined. One asbestos deposit in Alaska is dormant, but an asbestos deposit 55 miles to the east in the Yukon Territory is being mined by the Clinton Mine Div., Cassiar Asbestos Corp., Ltd. In this Bureau of Mines report, the economics of mining in the two locations were derived using the Clinton mine as a model. Both deposits were assumed to be of equal size and mined by similar methods. Conventional open pit mining and processing methods were assumed, and capital and operating costs were derived using flowsheets and standard costing methods. The estimated cost for the mine, mill, and support facilities in Alaska was about 30 percent more expensive than that in the Yukon Territory. The higher labor rates in Alaska were the primary contributor to the higher construction costs; freight rates added only slightly to the total costs. Approximately two-thirds of the additional annual costs of operating in Alaska were for wages and fringe benefits. The price required for the Alaskan asbestos fiber was $356.65 per ton compared with $287.44 for Yukon fiber, plus or minus 20 percent. A 12 percent discounted cash flow rate of return, 100 percent equity financing, and a rapid writeoff of assets were assumed.

Jan 1, 1975

By J. C. Stankus

Accurate evaluation of stress and geological conditions is critical to ground control design in underground openings. For a slope entry, the problem is more difficult because a slope will transverse through many different types of strata. Over the past three years, Keystone Mining Services, LLC, an affiliate company of Jennmar Corporation, has developed a new methodology designated the ?Stress, Geologic, and Support Design System (SGSsm)?. This patent pending method analyzes the stress, geology, and support design for a mine slope. It has been successfully applied in various new slopes across the United States. This paper will detail the main concepts of the methodology including: (1) Analysis of stress and geology and identification of strong, fair and weak zones along the slope; (2) Primary and supplemental support design; (3) Long term support design in the form of steel square sets or arches, and (4) Validation of the support design utilizing advanced finite element computer modeling.

Jan 1, 2011

By William A. Beck

"In 1912 bauxite was discovered in the Andersonville district, which lies in the 28th and 29th land districts of Georgia and comprises parts of Sumter, Macon, and Schley Counties. Mining was begun in May 1914 by the Republic Mining & Manufacturing Co. Considerable ore has been produced in this region since that time by individual interests and by the American Cyanamid & Chemical Corp., which acquired the property formerly owned by the Republic Co.The area was examined in the fall of 1941 by representatives of the Bureau of Mines and the Geological Survey, after which a prospecting program was begun by the Bureau. Drilling was started on December 26, 1941, and continued until November 18, 1943. A total of 1,192 holes was drilled in the district, and 3,679 samples were taken and analyzed.Mineral exploration agreements were signed by 146 property owners covering 42,128 acres. Holes were drilled on 121 of these properties, which have a total area of 38,778 acres.Drilling under this project disclosed several new deposits, of which four have been completely delimited. Previous prospecting in this area by mining companies did not find bauxite, as it lies under heavy overburden. Work by the Bureau indicates 14,412,000 long tons of ore containing 30 percent or more alumina. The total tonnage is divided as follows:Georgia State Highway Routes 26 and 4-9 traverse the district. The Central of Georgia Railroad passes through the center of the entire district (see fig. 1).The project was initiated by J. R. Thoenen, supervising engineer, Non-metals Mining Section, Mining Division, Bureau of Mines. It was under his general supervision until July 1942, after which it was under the general supervision of E. J. Lintner and Rowe McCrae, district engineers for Georgia, South Carolina, and Flordia, respectively.John C. Feeley, Jr., was project engineer from December 1941 to April 1942. Other engineers who assisted in the work on the project are R. E. Babcock, T. M. Romslo, Don M. Coulter, and Walter T. Lewiecki.Acknowledgment is due the metallurgical staffs at College Park, Md., and Tuscaloosa, Ala., for analyses of samples and beneficiation tests.Acknowledgment is also expressed to Alfred D. Zapp, M. W. Harris, Elmer Kneedler,and Parke D. Snavely, of the United States Geological Survey, for their aid, data, and maps.Bauxite was discovered in the Andersonville district in 1912 on lot 187 of the 28th land district, in Sumter County. This lot is situated about 1.5 miles west of the Flint River, on the south slope of the valley of Sweetwater Creek. Mining was started in May 1914 by the Republic Mining & Manufacturing Co. This and adjacent properties were acquired in 1930 by the American Cyanamid & Chemical Corp., which has been operating there since."

Dec 1, 1949

By Rainer Schmid-Fetzer

"Isothermal solidification can be used to form strong bonds at low temperature which remain solid at much higher temperatures. The exploitation of this principally known technique for new high temperature processing steps and applications in electronic assemblies is the aim of this study. Three basically different variants of this bonding process are given. A comprehensive metallurgical screening is performed and the feasibility of binary material systems is given on a quantitative scale. Very attractive systems are spotted that have never been studied before. Detailed examples for the realization of bonding with complex ternary and multilayer systems are given. A highly innovative example is the chip stack or wafer to wafer bonding of unmetallized Si or SiC at 250°C. The proposed bond remains stable above the melting point of Si and enables entirely new semiconductor manufacturing steps. An improved die bonding process was proposed and verified experimentally.1. IntroductionIsothermal solidification can be applied to form strong bonds at relatively low temperature which remain solid at higher temperatures. The general principle of this type of joining processes is illustrated in Fig. 1. An interlayer of a low melting component, Lo, is provided as a foil or a thin film coating between the high melting joint components, Hi. The assembly is heated under moderate pressure to the bonding temperature, T 8 , and a liquid filler forms, either because the melting point of Lo is exceeded or due to a eutectic reaction between Lo and Hi. This molten filler initiates a rapid interdiffusion or reaction diffusion between Lo and Hi and the subsequent approach to an equilibrium state results in isothermal solidification. The solid phases formed at T 8 in the joint region exhibit a remelt temperature above T8 •"

Jan 1, 1996

By Victor Dolmage

Introduction Although gold production in British Columbia began in 1859, lode gold was not produced till 1893. Since 1900, the annual production of lode gold has fluctuated between $3,000,000 and $6,000,000. About twenty per cent of this production may be regarded as by-product gold from base metal mining. The remainder comes from a few isolated but important mines, such as the Rossland mines, Nickel Plate, Surf Inlet, Premier, Pioneer, Bralorne, Reno, and Cariboo Gold Quartz, and from several less important mines. All of the above, except Pioneer, Bralorne, Reno, and Cariboo, are approaching or have reached the point of exhaustion, but all are now receiving, under the stimulus of the. present gold-mining boom, drastic resuscitative treatment, with, in some cases, signs of resurrection. Notwithstanding this, however, the main interest at the present time is focussed on the Bridge River and Cariboo fields. Both these fields were discovered in the early 'sixties' and, apart from the Cariboo placer production, both have from time to time contributed small amounts of lode gold; but it is only during the last two years that the real possibilities of these areas were discovered. and that they began to assume the appearance of goldfields of major importance. The two fields are sorme three hundred miles distant from one another and contain deposits of distinctly different types, so that the only reason for including them in one article is the fact that they came into prominence more or less simultaneously and at a time coinciding with, but not otherwise related to, the present gold-mining boom.

Jan 1, 1934

By Tassilo Baur

In the motion picture/television industry and to some extent in the entertainment industries in general, there is often a need to use energetic materials to create special effects as part of a production which travels, generally by truck. This can in certain instances create unique compliance challenges given that a production may change its filming location daily or even more often

Jan 1, 2009

By E Widzyk-Capehart

The mines of the future can be envisioned as complex, large-scale technological systems being operated remotely from few centrally located (major cities) operating centres and skeletal crew stationed at the site. These systems will require remotely located human operators to constantly adapt to new and unforeseen system and environmental demands. In addition, the remote operators will need to match system properties to the changing demands and operational conditions, ie must be able to handle the ‘non-design’ emergencies, because the system designers would not have been able to foresee all possible scenarios of failures and provide automatic safety devices for every contingency. Therefore, it is highly important that the operators’ job, which involves problem solving and decision making at the workstation level, is facilitated by the proper interface designs. This paper argues that decision support systems and thus human-system interfaces for the mines of the future should be developed based on the principles of human-system integration that take into account human information processing and cognitive abilities. The information presented to the operator must support the operator in taking appropriate action through a human-system interface designed according to scientific principles of User Centred Design. A case study is presented where an iterative design process was used by CSIRO researchers as an evaluation method involving users (control room operators) at several stages of the user interface design in order to correct any design inadequacies as they emerged. This process allowed the designers to identify any usability issues before the user interface was fully implemented, which subsequently enabled the control room operators to easily adapt to the new interface and carry out all designated tasks in a timely and effective manner.

Nov 22, 2011

By Abhijit Saha

"Two analytical closed-form elastic-rigid-plastic solution methods to predict the rigid foundation behaviour on stone-column reinforced soil are compared, both of which takes into account the stone material yield within the host soil according to stress-dilatancy theory. These are the mechanistic methods developed by the author (2004, 2005) [that presently incorporates the dilatancy angle as per Schanz and Vermeer (1996)] and that developed by Pulko and Majes (2006), that takes into account the column yield as per Rowe dilatancy theory. Since optimal design of stone column necessitates optimum stress concentration on column, which is generally composed of dense gravel with/or without sand, the vertical stress on granular column is often close to its peak strength and the material dilates. To arrive at closed-form analytic solution to this complex soil-stone column interaction problem, some common assumptions like axi-symmetric soilstone column ‘unit-cell’, elastic host soil and rigid-plastic Mohr-Coulomb stone column material are combined with equilibrium and kinematic conditions. The results reflect the beneficial effect of dilatancy within the optimal range or techno-economic domain of area-ratio. The settlement predictions are compared with other analytical methods available in literature as well as with measured settlement reduction of stonecolumn reinforced ground at different subsoil conditions around the globe reported in literature.INTRODUCTIONStone columns or granular piles are frequently used in stabilization of soft clays, silts and loose silty-sands with large amount of fines. The majority of analytical methods assume infinitely wide loaded area with end-bearing columns having constant diameter and spacing that approximate to axi-symmetric conditions, and the approach is known as ‘unit-cell concept’. Several analytical solutions are available, and many of them (Aboshi et al; 1979, Balaam & Booker; 1981) are based on elastic approach considering the stonecolumn and surrounding soil as elastic materials. However, elastic methods give the ratio between the vertical stress in the column to soil (stress concentration factor) approximately equal to the ratio of constrained modulus of both materials. This ratio was found to be considerably higher than measured in the field and it is believed that elastic methods may overestimate the effects of stone columns on settlement reduction (Barksdale & Bachus, 1983). The elastic and elasto-plastic solutions presented by Balaam and Booker (1981, 1985) indicate that the problem can be idealized by assuming that the stone column is in a triaxial state and possibly yielding, such that there is no shear stress at the stone-soil interface and no yielding in the soil. Similar assumptions of stone column to be in a state of limiting equilibrium and under a triaxial stress state are considered in other methods also (Priebe; 1976, Van Impe & De Beer; 1983, Van Impe & Madhav; 1992, Saha & De; 1994, Saha; 2004, 2005, Pulko & Majes; 2006). In majority of the methods it is assumed that under load the stone-column yields at constant volume. However, the last three cases cited consider another parameter; the dilation of stone column. In Van Impe and Madhav’s (1992) and author’s (2004, 2005) method, the dilation is taken into account through the final value of the volumetric strain of column, whereas Pulko & Majes (2006) considered the stone column as Mohr-Coulomb rigid-plastic; dilating at yield in line with Rowe (1962) dilatancy theory."

Jan 1, 2015