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By Sepideh Damavandinejad Monfared

"In recognition of the practicality of using inclined micropiles as elements for foundation support to resist static and seismic loading conditions, specifically in retrofitting projects, this study presents an investigation into the behavior of an inclined micropile subjected to simultaneous lateral load and bending moment. Three-dimensional numerical simulations are performed using the finite element method to assess the influence of micropile geometrical parameters such as angle of inclination, length, and diameter on the response of micropile-soil system. The Mohr-Coulomb failure criterion is used to define the behavior of soil and stabilized soil around micropile materials and the micropile, constructed of concrete and steel, is assumed to be elastic. The interaction between soil and micropile is taken into account by defining interaction elements covering both tangential and normal behavior. The study is carried out using nonlinear FEM analyses. The results of these simulations indicate that negative micropiles, in which slip surface deflects downward, have higher lateral load capacity than positive micropiles with slip surface deflecting upward. The conducted research also shows that increasing the diameter and the length of micropile increases the lateral load capacity. Increasing micropile diameter is more effective in increasing lateral load capacity. A relationship is developed from statistical regression analysis of the finite element modeling computations to estimate the lateral displacement of a micropile inclined at an angle of 30o in silty sands. IntroductionMicropiles are small diameter (typically less than 300 mm), cast-in-place, drilled, and grouted replacement piles with steel pipes which after being conceived in Italy (Lizzi,1978), were originally developed for underpinning existing structures (Bruce et al.,1990) to arrest and prevent structural movement, upgrade loadbearing capacity of existing structures, repair or replace deteriorating or inadequate foundations or raise settled foundations to their original elevation."

Jan 1, 2017

By Henry M. Howe

I wish to present to you a few thoughts on some of the phenomena and laws of iron smelting. Owing to the great complexity of the subject, to the great variety of points to be taken into consideration, many of which are very poorly understood, and to the meagreness and even conflictoriness of our information with regard to some of the most important laws which govern the subject, the fruits of such thoughts as I venture to offer you must be received as speculations, not as facts. Nevertheless, in discussing old phenomena from new standpoints, thus furnishing a metallurgical parallax, if I may say so, these theoretical speculations may have their value in helping to a clearer comprehension of the phenomena and laws we now know, and in suggesting new lines of inquiry. While an increase of height in blast furnaces is not always followed by increase in their power of production, experience proves that it tends to increase it; for while we have many cases of short furnaces producing more iron than longer ones, yet enormous productions, such as those of the Lucy and Isabella furnaces of Pittsburgh, and of the furnaces of Esch sur l'Alzette, in Luxembourg, have never been reached in short furnaces. We may safely infer that height is an element essential to great production, though of course not the only essential element, and that, in the case of high furnaces which are not capable of great production, some other essential element is wanting. Moreover, experience teaches that within limits increase of height tends to increase the producing power in a still higher ratio. Thus, in the Esch furnace, which is 19.8 meters (65 feet) high, 393 tonnes (or 387 gross tons) of 31 1/2 per cent. Ore

By Gilbert Thiessen

THE purposes of this paper are (1) to show that the mineral matter content of coal is satisfactorily represented by the Parr formula; that is, Mineral matter = 1.08 Ash + 0.55 Total sulfur (2) to compare ash-to-mineral-matter ratios with factors by which ash values must be multiplied in order that dry, factor-times-ash-free values shall equal Parr unit coal values; (3) to examine such ash-correction factors and to compare them with similar factors corresponding to certain simplifications or modifications of the Parr formulas and (4) to show that ash-correction factors used for simplification in calculating approximate unit coal calorific values cannot be. correctly used for the conversion of other determined values in an analysis to the unit coal basis, but that each type of calculation requires separate treatment in simplification.

Jan 1, 1934

By Fradd WP

South Australia pioneered metal mining in Australia and was the main source of copper for several decades. Gold discoveries and mining also contributed significantly to the development of the Colony. Across the State can be seen the holes, the mullock heaps and, in some instances, the remnants of machinery of the past era. In this, the centenary year of the discovery of the Teetulpa goldfield, considered by some to he the most significant discovery of gold in the State, it is appropriate that we should present a paper on the history of gold mining in South Australia. South Australia has not been a major producer of gold with recorded production a little in excess of 15 million grams (15 t). This represents about 0.25 per cent of the Australian total and ranks last of the States of the Commonwealth. The outstand- ing feature of gold production in South Australia has been the succession of short periods of rela- tively high production immediately following a discovery, with payable dirt being quickly exhausted, a fact clearly illustrated by the graph of South Australian gold production (Figure 1).

Jan 1, 1987

By Joseph Hartshorne

The nature if this process and the general course of its development have already been described by me in two papers read before the Institute.* Since the latter paper mas read, in February, 1898, the development at Kladno has been almost altogether in the direction of using metal direct from the blast-furnace. This has now been the regular practice for about a year. The molten metal is brought from the furnace in ladles, without the intervention of any mixing- or accumulating-reservoir. The plant remains practically the same as originally described by me,† except that the primary furnace has been enlarged as much as was permitted by the existing conditions. This was done primarily in order to increase the capacity of the

Jan 1, 1901

By Joseph M. Hans

INTRODUCTION The decontamination of a uranium mill site is principally an earth moving task. The task can be completed effectively and efficiently by selecting the proper earth moving equipment and using that equipment within its particular constraints for decontamination work. A considerable backlog of experience concerning earth moving equipment selection and use was acquired during the decontamination work conducted at the former Shiprock, New Mexico, uranium mill site. This experience was acquired by trial and error while decontaminating over a wide range of depths and different types of terrain. Many different types of excavation equipment were available to the Shiprock decontamination project because the Navajo Engineering and Construction Authority (NECA) heavy equipment operator's school was doing the decontamination work and a variety of equipment was needed for training. The equipment is described and its general use for decontamination is discussed. Its on-the-job use for decontaminating the Shiprock millsite is presented. [EARTH MOVING/ANCILLARY EQUIPMENT DESCRIPTION AND DECONTAMINATION CONSTRAINTS] Tractor-Scrapers The most commonly used scraper is the bottom-dump type because it is highly mobile and can dig, carry, and spread loads. In this type a tractor is connected with a yoke to a scraper bowl (Figure 1). The bowl is essentially a rigid box that pivots around the rear axle, opening to the front. A hardened steel knife, or bit, is attached to the leading edge of the bowl. When scraping, the bit penetrates and forces the earth overlying the bit edge into the scraper bowl as the scraper moves forward. When the bowl is full, it is closed by lowering a closure or apron against the cutting bit. The load is dumped while moving, by raising the apron and forcing the load from the bowl with a crowd, or ejector. The height of the dumped load is controlled by adjusting the bit height when dumping. Scrapers of this type generally do not have enough power to scrape up loads unassisted. Loading assistance is generally provided by a crawler tractor that pushes from the rear against the scraper's push block. Some scrapers are made self-loading by adding an additional engine for the extra power needed for the load pick up. Another commonly used self-loading scraper uses a loading elevator (Figure 2). The elevator consists of two roller chains carrying crossbars. The elevator is rotated when scraping and the crossbars cut the earth above or in front of the bowl bit, forcing the load into the scraper bowl. No apron is used on elevating scrapers. The load is dumped by partially retracting the bowl floor and pushing with an ejector. Scrapers have some undesirable characteristics when used for decontamination work. One characteristic is that a clearance space exists around the apron when it is in its closed position. Part of the load (especially sandy soils) dribbles through the

Jan 1, 1981

By M. Cohen, S. A. Kulin

AT a recent symposium on thermodynamics in physical metallurgy1 two opposing theories of the austenite-martensite transformation were presented. Both theories agreed that this type of reaction involves a nucleation process which requires activation and that the activated nuclei develop into the well-known martensite plates with tremendous speed. However, there were essential differences in the two points of view concerning the nature of the nucleus and the mechanism by which the nucleus propagates. According to Cohen, Machlin, and Paranjpe,' the nucleus is a strain center with sufficient elastic energy to initiate a cooperative displacement among the atoms of the parent phase when a sufficiently low temperature is reached. This displacement propagates as a wave in shear-like fashion to transform the austenite into martensite without benefit of diffusion. On the other hand, Fisher, Hollomon, and Turnbull3 regard the nucleus as a solute-poor region (in the austenite) of a size which becomes supercritical relative to coherent growth into martensite when an appropriately low temperature is reached. This growth process is taken to be an atom-by- atom transfer from the receding austenite lattice to the advancing martensite lattice through the coherent interface that exists between the two phases. The present paper is not conceded with the divergent views as to the nature of the nucleus but describes some critical experiments which differentiate between the two proposed mechanisms of propagation. Fisher' has summarized the latter issue in the following way: According to the cooperative displacement theory, the speed of formation of mar-tensite plates should not be decreased by lowering the temperature, and martensite should form with extreme rapidity at very low temperatures; whereas with the alternate growth process, the speed of the martensite transformation should be retarded at very low temperatures, decreasing to zero at the absolute zero. The atom-by-atom growth mechanism predicts a marked slowing down of the reaction rate with decreasing temperature because the rate of self-diffusion in the austenite is involved in this picture. For example, Fisher, Hollomon and Turn-bull5 estimate that the activation energy for this growth process in steel is (0.34)2(0.36)* times the activation energy for self-diffusion in y-iron. The two most recent determinations of the latter quantity are 67,900" and 74,2007 cal/mol, which may be averaged as 71,000 cal/mol. This, in turn, gives a value of 3000 cal/mol for the activation energy of the atom-by-atom process, and hence the rate of growth should vary as e 8,000/RT where R is the gas constant

Jan 1, 1951

By Robert Hopler

The 1800’s were a time of tremendous advancements in science and experimentation, and earthquakes were a subject of great interest. The meetings of the British Association for the Advancement of Science in 1853 and 1854 are good examples of this. The proceedings of the Association for the 1854 meeting includes a table entitled “Catalogue of Recorded Earthquakes from 1784 to 1850” which takes up 326 pages, and lists available information on approximately 3000 earthquakes. The 1853 proceedings have a similar table for earthquakes recorded from 1606 B.C. to 1783. In the 1854 volume there is a “Report of the Committee on Earthquakes,” which provides us with a view of the general state of the science. Excerpts from that report follow:

Jan 1, 2006

By V. de la Garza

The La Cienega Gold District is located at latitude 25°01'01"N and longitude 106°19'00"W, in the NW part of the State of Durango, Mexico. Ore deposits at The La Cienega District consist of a series of sub-parallel, NE-trending veins which cut andesitic and rhyolitic rocks that belong to both upper and lower tertiary volcanic sequences. The veins are vertical to steeply-depping structures which consist of quartz, generally containing gold-silver and less than ten percent lead, zinc and copper sulfide and sulfosalt minerals. Supergene enrichment is present on the upper parts of known oreshoots. Tertiary volcanic rocks of rhyolitic composition are the main host rocks of the gold-bearing quartz veins in the District. Gold productionc from the La Cienega orebody is scheduled to reach 100,000 ounces per year, becoming the largest gold-producing District in the Sierra Madre Occidental Province.

Jan 1, 1994

By Howard S. Bryant

The state of Kansas in 1931 continued to hold fourth place on the list of oil-producing states, despite the fact that low prices for crude oil curtailed drilling to just one-half the amount done in 1930, which itself was the lowest in the preceding 10 years. The estimated crude oil production for 1931, according to sources available to the writer, will approximate 37,037,000 bbl., the lowest since 1925. Thus Kansas produced one-eighth less oil this year than it did last year when it produced 42,729,085 barrels. This year's development was characterized by a very small amount of wildcat drilling; however, large new areas were semiproven for oil production, and several thousands of acres were added to the actually proved areas in western Kansas, so that the state now has larger proven areas of oil reserves than at any time in its history since the heyday of the famous El Dorado pool. The general prospects for oil production in the near future are indeed promising for central western Kansas, where drilling costs are moderate and depths are relatively shallow compared to the remaining unexplored parts of the northern Mid-Continent area. Probably the greatest singular achievement in the state for 1931 was the development of its natural gas reserves. This development took place principally in two spots, McPherson County in central Kansas, and Stevens and Morton counties in southwestern Kansas, and it is a matter of record that more than one and one-half billion cubic feet of open-flow capacity per day were added to reserves, nearly twice the amount developed in 1930, previously the largest amount in the history of gas development in Kansas. Gas pipe lines already built and now building are in position to deliver natural gas by one system to Chicago, Ill., by another to Indianapolis, Ind., from whence lines already lead practically to the Atlantic seaboard, and to other cities large and small located west, northwest, north and northeast of Kansas. Table 2 shows all well completions for 1931 in a form to compare with the results of previous years.

Jan 1, 1932

By J Maxlow, M J. Woods, M P. Sandy

The Newcrest Mining Limited Telfer operation comprises both open pit and underground operations producing gold and copper. The underground operation is made up of three production areas, the sublevel cave (SLC), M Reefs narrow vein open stoping and Western longhole open stoping areas. With stoping situated on the abutments of a mature and active sublevel cave, the interaction between mining areas is often complex. This is particularly evident in the M Reefs orebodies with high levels of extraction in all four reefs, and reliance on pillars to maintain local and global stability. A key concern was the potential for a cascading pillar failure to develop and rapidly progress through the M Reefs stoping area. The monitoring plan needed to capture any change in overall stability and identify if deformation was caused by pillar failure within the M Reefs and hanging wall closure, or shear on the reefs caused by SLC influence.

Nov 29, 2022

By Kenji Monden

"In order to obtain basic data for the development of highly thermally conductive composite materials, the thermal conductivity of a resin composite material with an Aluminum Nitride filler was assessed. Several different measurement techniques such as the xenon flash and the temperature wave thermometric analysis method were employed to gather data on these composites. An excellent match between theoretical and experimental data was achieved by employing a predictive expression that takes into account the effect of percolation on thermal conductivity.IntroductionA thermal solution composite is made by incorporating dense inorganic fillers with high thermal conductivity into a resin. Because the composite materials have high thermal conductivities, they have been used in electrical products that generate excessive thermal energy during operation, such as inverters, amplifiers and motor drivers. They function as electrically insulating and thermally conducting parts of the electric modules. As the uses of thermal solutions are expanded, composites of higher thermal conductivities will be required. The aim of this work was to investigate, evaluate, and try to predict the influence of key parameters on thermal conductivity and diffusivity. This was achieved by analyzing the effect of both volume fraction and shape of Aluminum Nitride ceramic fillers and measuring the thermal conductivity. In addition, the influence of percolation on thermal conductivity is considered. The thermal conductivity of the composites is discussed by employing a predictive equation using literature data of thermal conductivities for both the filler and resin. As well as thermal conductivity measurements the effect of volume fraction of the filler was also explored.ExperimentalSpecimen PreparationThe composite samples were prepared from silicone resin and Aluminum Nitride (AlN) fillers. The AlN fillers with an average particle size of 20 µm are shown in Figure 1. The mean diameters of the AlN particles used are given in Table I. For comparison the AlN fillers with an average particle size of 5 µm are shown in Figure 2. A planetary centrifugal mixer was used for simultaneously dispersing the components uniformly and de-aerating the mixture. After mixing, these materials were placed in a silicone rubber case and cured at 150 °C for 1 hour."

Jan 1, 2013

By Tapp B. A

To date, few studies have been made regarding the energy requirements of the Australian mining and mineral processing industries. This paper indicates that these industries use a substantial proportion of the total Australian energy input (32.7% in 1971-72 and 36.10% in 1974-75). With the growth orientation of these industries, this input is likely to increase. Data shows that mining energy requirementE varied from 4.22% (of total Australian energy requirements) in 1971-72 to 4.16% in 1974-75. Energy requirements for the total mineral processing industries increased from 28.49% to 31.93% for the same period. The total estimated primary energy input varied from 22.56% to 25.2%, whilst indirect energy use, in the form of electricity increased from 10.16% to 10.66%; in the same period. Analysis of primary energy input data within the processing industries (1973/4) showed that the Iron and Steel Industry consumed 15.03% of the Australian total consumption, Non-Ferrous metals, 5.43%, Cement, 1.64%, and Refractories, 1.59%. In toto this represented 24.57% of the total

Jan 1, 1979

By Waldemar Lindgren

CONTENTS. [ ] I.-CHARACTER OF THE DEPOSITS. 1. Principal Features. IN many schemes of classification and description the term contact-deposit has been somewhat loosely applied to all accumulations of useful minerals (other than those of unquestioned sedimentary origin) which are enclosed between two different rocks. As thus used, the term may include deposits of widely differing origin, and, unless qualified, is not in place in a genetic classification. The present paper deals with a special class of contact-deposits. In many geological provinces, granular igneous rocks, such as granite, diorite and syenite, have broken through and invaded sedimentary rocks. The molten magma may in part have reached the surface and there solidified with relative rapidity as a lava. The largest masses of it, however, did not reach the surface, but cooled very slowly at considerable depth under great pressure, and eventually consolidated into a rock of granitic texture. Uplifts and extensive erosion may have followed; and at the present day, in many places, thousands of feet of material have been removed, bringing to the surface the intrusive granular rocks and their once deep-seated contacts with the sedimentaries which they shattered at the time of in-

Jan 1, 1902

By A. J. Hendron, B. Mohraz, R. B. Peck

INTRODUCTION The state of the art of soft-ground tunneling was discussed in detail by the senior author at the 7th International Conference on Soil Mechanics and Foundation Engineering held in Mexico City in 1969. Little can be gained by repeating the information assembled at that time. Hence, in this report, only the briefest summary will be given of the overall state of the art and attention will be concentrated on trends and developments since 1969. A characteristic of recent developments is the continued trend toward use of shields and excavating machines. The implications of this trend with respect to design and construction, and particularly with respect to the treatment of unfavorable ground conditions, will be examined. Settlement associated with lost ground, a subject as old as tunneling itself, will be reviewed and methods will be considered for its reduction. Design of tunnel supports was discussed in detail in 1969 with respect to essentially rigid or essentially flexible types of linings. In this report, a definition of flexibility will be considered and design procedures suggested for linings of flexibility intermediate between the two extremes.

Jan 1, 1997

By David M. Hyman

The Bureau of Mines has developed two experimental designs for deter- mining the volumes and relative proportions of the various gas species, particularly methane (CH4), occluded in rock salt. To date, the rock salt samples analyzed have been relatively small (400- to 1,000-gram) grab samples from Louisiana Gulf Coast domal salt mines. The results obtained are comparable to results in Polish domal salt mines, in terms of occluded gas volumes per mass of rock salt. The notable difference between the Louisiana and Polish occluded gas mixtures is in the relative proportions of the individual gas species. The two methods used by the Bureau are ballmill crushing and dissolution. Of the two, the dissolution method appears to be more versatile because it can be performed in situ. The relevance and applicability of data on the occluded gas contents of rock salt are dependent on sample size, sample collection method, geologic context of the sample, and the correlation with gas emissions that occur as a result of mining-induced fractures and pressure differentials.

Jan 1, 1982

By John Hays Hammoud

At the Annual Business Meeting of the Institute, held February 19, 1907, the following persons were elected Council. President of the Council, John Hays Hammond, New York, N. Y. Vice-Presidents (for two years), Samuel B. Christy, Berkeley, Cal. ; John A. Church, New York, N. Y.; Persifor Frazer, Philadelphia, Pa. Councilors (for three years), B. F. Fackenthal, Jr., Easton, Pa.; H. 0. Hofman, Boston, Mass.; Walter Renton Ingalls, New York, N. Y. Secretary. of the Council (for one year), Rossiter W. Raymond, New York, N.Y.

Mar 1, 1907

By Donald H. Matthews

The usual method of dismantling massive concrete formations with explosives, is to totally demolish the entire concrete structure. If any portion of a concrete structure is required to remain in its original form and retain its structural integrity, the use of explosives is usually forbidden and the portion to be dismantled is demolished by mechanical means, using various techniques and equipment that are tedious and expensive.

Jan 1, 1978

By R. G. B. Pickering

The Faculty of Engineering at the University of the Witwatersrand and the Mining Technology Division of the CSIR have co-operated to define the problems associated with deep level mining and in this paper they will identify what they consider to be the critical areas requiring technological solutions. This perspective will then be applied to work currently being carried out by both the organizations and gaps for additional developments will be identified. Finally the Co-operative Research Centre methodology operating in Australia is described. The purpose of this CRC is to provide a vehicle for R&D co-operation to develop and implement technologies which will increase the competitiveness of the mining industry. A further objective is to develop an appropriately skilled human resource base.

Jan 1, 1996

By Jorma Miettunen, Reijo Kalapudas, Pertti Koivistoinen

A new method for measuring the mill filling was developed by Outokumpu’s Pyhäsalmi concentrator during 1989-90. The method utilizes the power draw oscillation which is caused by the mill lifters. Each lifter bar causes a peak in the power draw and thus a continuous oscillation results. In a fixed time scale, the oscillation peaks will shift as the lifter bare hit the mill charge sooner or later depending on the volumetric filling of the mill. Thus the measuring method is based on the phase shift of the power oscillation. So far the measurement is utilized for maximizing throughput of the primary mills at Pyhäsalmi and Enonkoski concentrators and at Harjavalta slag concentrator. The paper describes the new method and the results achieved.

Jan 1, 1992