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By H. Jung, J. Kim, Y. Lee, Y. Seo

"Shale gas has become an increasingly important source of natural gas supply in North America and around the world. Horizontal drilling and multi-stage hydraulic fracturing are the two key enabling technologies for the economic development of these shale gas reservoirs. It is believed that gas in shale reservoirs is mainly composed of free gas within fractures and pores and adsorbed gas in organic matter (kerogen). It is generally assumed in the literature that the monolayer Langmuir isotherm describes gas adsorption behavior in shale gas reservoirs. In this work, we have analyzed several experimental measurements of methane adsorption from the Horn River Shale core samples that obey the Langmuir isotherm. INTRODUCTION In nature, gas shales are characterized by extremely small grain size, extremely low permeability on the order of nano-Darcy (10-6 md), small porosity, and high total organic carbon (TOC). Shale can serve as both source and reservoir rock. The amount of gas in place in shale is strongly affected by the TOC, clays, and the adsorption ability of methane on the internal surface of solid (Martin et al., 2010). Since a considerable amount of gas in shale reservoirs is adsorbed, investigation of gas adsorption can provide critical insights into evaluation of well performance and reservoir characterization. Generally, natural gas in shale reservoirs is stored as free gas in both larger mineral pores and natural fractures, as well as adsorbed gas within organic matter (Leahy-Dios et al., 2011). EXPERIMENT METHOD & THEORY Adsorption Experiment Several experiments were carried out on 9 shale core samples obtained in a vertical well drilled within Horn River basin (Figure 1). The CH4 adsorption isotherms were measured for the different depth. In order to measure the amount of adsorbed gas, the high pressure Belsorp-HP equipment applying volumetric method was used. The temperature was kept at 298 K and pressure was increased up to 18 MPa. Approximately 5 g of crushed sample was used for each measurement."

Jan 1, 2016

By R. I. Jaffee, J. G. Dunleavy, W. Hodge, H. R. Ogden

IN a search for an improved conductor for use in field wire for the L. S. Army Signal Corps, an alloy of copper and silver was developed from which it was possible to obtain 29 B & S ga. strands with tensile strengths in excess of 160,000 psi combined with an electrical conductivity of over 70 pct IACS. Such a favorable combination of strength and electrical conductivity has not been reported previously in the rather extensive literature covering this subject. The properties obtained from various binary alloys of copper and silver, together with the method of fabrication of these alloys which has been developed to obtain the properties desired in fine wire strands, are discussed in this paper. LITERATURE The effect on the electrical conductivity of copper of the various elements in solid solution is shown in Fig I, taken from published data by J. O. Linde and others.' It will be noted that silver in solid solution depresses the electrical conductivity to a lesser extent than any other element for which data are given, and is followed rather closely by cadmium, and then by chromium. Zinc, which lies between cadmium and chromium, has so high a solid solubility in copper that the data for zinc are scarcely comparable to the data for the other two in the range covered. Not many data are available on the strain hardening of copper-rich Cu-Ag alloys. Corson2 reports a 3 pct Ag alloy properly cold worked and annealed to have 100,000 psi tensile strength and 90 pct IACS conductivity. On straight cold working, Hessenbruch3 reports 101.000 psi for a 5 pct Ag, 0.3 pct Be alloy, and 129,000 psi for a 30 pct Ag, 0.5 pct Be alloy. Here it would he expected that much of the strain hardening came from the silver content of the alloys. The copper-rich side of the Cu-Ag diagram, according to Stockdale,4 is shown in the upper part of Fig 2. The electrical conductivities for copper-silver alloys annealed at 750 and 350°C, taken from the work of Johansson and Linde,5 are shown in the lower part of Fig 2. The sloping line corresponds to the conductivity of solid solutions of silver in copper, and the horizontal offshoots correspond to the conductivity of the two-phase alloys in equilibrium at the two temperatures shown. The electrical conductivities are very high, even for the 750°C anneal. The potentiality for age hardening from supersaturated alpha copper solutions appears to be excellent from the solubility line, but Smith and Lindlief6 have shown that the response to age hardening of solution-annealed alpha alloys is not good. They found that the tensile strength of a 5 pct Ag alloy aged at various temperatures was not as great as in the quenched condition, even though, anomalously, the hardness increased from RB68 to RB78 by annealing for 4 hr at 400°C after a 750°C quench. Weist7 also found that the alloys increased in hardness

Jan 1, 1948

IN speaking, on the subject, "Engineer-Citizens," at the Lehigh Valley Mineral Industries Conference dinner, on April 26, at Easton, Pa., George Otis Smith, Director of the United States Geological Survey and President of the American Institute of Mining and Metallurgical Engineers, said in part: "It would be carrying coke to Connellsville to bring to the Lehigh Valley the idea that mineral resources are the foundation of national prosperity. Unfortu-nately, however, this obvious, fact is not everywhere recognized. Too many of our economists, journalists, statesmen and other dopesters of present business con-ditions stress the human factor so strongly that they overlook the material with which men work out their destiny. To them the financial psychology of Wall Street and the political logic of Capitol Hill and the business commonplaces of Main Street all loom far larger than the geology of the Lehigh Valley or the engineering triumphs of Bethlehem, or, the creative thinking at Lehigh and Lafayette. "The present situation in the industrial and .business world is a complex of interacting causes and reacting effects not easily itemized and entered on our trial balance sheet. But, chief among the liabilities of today is the excess of production capacity in most branches of industry. The farmer has no. monopoly in his desire for relief. Whether your professional connections are with steel or cement, coal or oil, copper, or zinc, you; know too well that for, the moment America is over-engined, and you keenly realize the ever-present hazard of industry speeding up regardless of the curves or grades just around the corner.

Jan 5, 1928

By J. V. W. REYNDERS

FIRST of all let me express my affectionate gratitude for the cordiality and good will of your reception. On the part of the men I venture to interpret the character of your greeting, not only as a recognition of the position to which you have been good enough to elect me, but also as an expression of your friendly attitude. However, I cannot pass over the tribute of the ladies so casually: Nor does it seem possible to do justice to my sentiments in addressing them collectively. I would feel more equal to the task if I could have the opportunity to talk to them singly, in doing which I know I may count upon their good sportsmanship not to compare notes. There has been some discussion between Mr. Kelly and myself as to our respective duties on this occasion: The precedents are not clear as to whether the retiring or the incoming president is expected to speak at length. Mr. Kelly's argument was that as the incoming president confines himself to promises for the future his field is a broad one and his opportunities for extending his remarks correspondingly unlimited.

Jan 1, 1925

By B. Post, D. Moskowitz, F. W. Glaser

Lattice parameters of various hafnium compounds, two borides, a carbide and a nitride were determined. Some physical properties were measured and comparisons with the properties of the corre-sponing zirconium compounds were drawn. A LTHOUGH borides of transition metals have A been extensively investigated in recent years, there are few references in the literature to borides of hafnium. This is not surprising, in view of the extreme scarcity and great cost of the purified metal. Becker' reported the existence of a boride, carbide, and nitride of hafnium; he listed the formulas as HfB, HfC, and HfN. However, in his work no mention was made of chemical analyses of the reaction products. In this paper results of a study of various hafnium compounds, including borides, carbides, and nitrides, are reported. It was expected, of course, that these compounds would closely resemble their zirconium analogues, which have previously been extensively investigated. Three borides of zirconium are known: ZrB,² ZrB,² and ZrB212.4 In addition, one carbide, ZrC,5 and one nitride, ZrN,5 have been reported. It should be noted that ZrB and ZrB12 are stable phases only in relatively high-temperature regions, unlike ZrB2, which is stable from room temperature to its melting point." It was felt that hafnium would yield corresponding borides, carbides, and nitrides with similar stability ranges. Experimental Procedures and Results A quantity of hafnium metal that was better than 97 pct pure, with zirconium as its major impurity, was furnished by the Argonne National Laboratories. The boron powder used was approximately 96.5 pct pure. In general, the procedure involved mixing the metal and boron powders in the desired proportions, and subsequently hot pressing them. The resulting specimens were analyzed chemically and phases present were identified by X-ray diffraction methods. A Philips Norelco Geiger counter spectrometer was used for identification of components and for measurement of lattice constants. Filtered copper radiation was used for all X-ray work. Electrical resistivity and density measurements were carried out at room temperature. The stable diboride, HfB2, will be described first. Stoichiometric quantities of boron and metal were heated to approximately 2000°C during hot pressing. The reaction product was shown by X-ray diffraction methods to be isomorphous with ZrB2 (space group Dlgh; P6/mm). Values of lattice constants of HfB2 compared with those of ZrB2 are shown in Table I. The calculated density of HfB2 is 11.2 g per cc, compared with a measured (pycnometric) value of 10.5 g per cc. HfB2 specimens prepared under a wide variety of conditions (including variations in initial Hf-B ratios) showed only insignificant variations in lattice constants, indicating a very narrow range of homogeneity. Like ZrB2,7 HfB2 is an excellent electrical conductor. The resistivity at room temperature of hot-pressed samples, approximately 85 pct dense, is 12 microhm-cm. This compares favorably with the electrical resistivity of 10 mi-

Jan 1, 1954

By David E. Morse

Burundi, a small central African republic located between Tanzania and Zaire, remained essentially a nation of small family farms in 1978-79 with approximately 95% of the population engaged in subsistance agriculture. Coffee and tea continued as the nation's major export commodities. Mineral exports, small tonnages of cassiterite, wolframite and bastnasite, accounted for an estimated 3% of total exports in 1978 and 2% in 1979, or $2 million2 in both years. Burundi's major mineral imports in 1978-79 were cement, iron and steel, and refined petroleum products. Abnormal weather conditions, a drop in world coffee prices in 1978, and the conflict in neighboring Tanzania and Uganda in late 1978 and early 1979 combined to re-strict economic growth in Burundi during 1978-79. The gross domestic product (GDP) posted a gain of 6.7% in real terms for 1978 and an estimated 2.5% for 1979 which was significantly less than the 13.7% recorded in 1977, a time of high world coffee prices. The manufacturing and construction sectors were hard hit in 1979 by the conflict between Burundi's eastern neighbors because of transport disruptions which made building materials and manufacturing inputs almost unobtainable.

Jan 1, 1981

By H. F. Seifert

THE classification and preparation of non-ferrous scrap metals is a subject of interest to every individual and corporation that employs in its processes of manufacture non-ferrous metals and alloys and accumulates in such manufacture scrap from these materials for disposition in the form of turnings, borings, short ends, punchings, clippings, grindings, washings, etc. All too frequently the disposition of such scrap is left to individuals who have no knowledge of the subject either from a metallurgical or a commercial standpoint, or both. Much money is thus lost which with a little more intelligent effort might be saved, and in this day of fierce competition and small profits such an opportunity cannot be ignored. The Mineral Resources of the United States for the year 1925, the latest issue available (Part 1, page 221), gives the secondary non-ferrous TABLE 1.-Some Secondary Non-ferrous Metals Recovered in the United States for the Year 1924-25 Material Short Tons Value Copper, including that in alloys other than brass.... 250,600 $ 71,170,400 Brass, scrap remelted 242,300 56,270,800 Lead as metal 112,4201 39,477,100 Lead as alloys 112,460 Zinc as metal 61,430 11,359,000 Zinc -in alloys other than brass 13,300 Tin as metal 1 7,950 35,165,400 Tin in alloys 23,000 Antimony as metal 1 } 3;794,000 Antimony in alloys 10,839 Aluminum as metal 17,700 24 Aluminum in alloys 26,300 ,816,000 Nickel as metal 19 1 1,518,000 Nickel in non-ferrous alloys 2,109 Total 882,600 $243,570,700

Jan 1, 1928

By R. J. Mechin

TOP-SLICING was introduced in the Pachuca district in 1917 by T. C. Baker, at that time mine superintendent, of the Santa Gertrudis mine. There then existed 1200 ft. (365.7 m.) below the surface, lying between the fourteenth and eighteenth levels (a vertical distance of 108 meters) a block of ore having a length of 295 ft. (90 m.), and an average width of 82 ft. (25 m.) and dipping at an angle of 65°. This block lay in the hanging wall of the vein and consisted of highly altered and fractured andesite, cut through with mineralized quartz stringers. On the foot-wall side, 26 ft. (8 m.) of old filling, left by former operators, was of payable grade. Stoping therein was first undertaken by the square-set filling system, but because of the extremely heavy hanging wall and loose dry filling in the foot wall, all square setting had to be accompanied by spiling, which made the operation exceedingly slow and costly. A system of mining was sought that would eliminate the difficulties inherent to the square-set system in heavy ground and that at the same time would effect the desired economies in mining. After several years, top-slicing has met all the conditions most satisfactorily, so that when similar conditions presented themselves in El Bordo mine, this method was adopted with necessary modifications. El Bordo mine is operated by the Santa Gertrudis company, and is situated about two miles north of Pachuca. Because of the diversity of the orebodies, a number of different mining methods are in use, among them top-slicing.

Jan 10, 1925

By Juan Alvarez Lino

El Comité Técnico Consultivo del Gobierno Regional de Arequipa propone a la Comunidad Minera regional participar en el crecimiento económico regional mediante la reinversión minera en Proyectos productivos y de servicios de escala nacional e internaciona. El proyecto nace como el "Plan de Desarrollo Integral de la Región Arequipa” o Mega Proyecto Coropuna donde se da un planteamiento de ecodesarrollo integrado transversal mar-costa- sierra en dicesiete Ecozonas existentes, con la ejecución de Proyectos Hidráulicos, Hidroeléctricos, Agroindustriales, bioenergéticos, industriales, petroquímica, ecoturismo internacional, megapuerto, aeropuerto, ferroviarios, carreteras, balnearios internacionales y urbanos metropolitanos.

Sep 12, 2011

B. C. MADDEN, JR.2-My comments have no connection with any particular paper; however, since we have talked of stress-corrosion cracking of aircraft parts, cartridge cases? coffee urns, bridge wire, etc., I feel I must mention the apparent significance of this symposium being held in Philadelphia, where perhaps the most famous stress-corrosion crack exists-that of the Liberty Bell. This noon I took advantage of an opportunity to see the Liberty Bell; I commend it to your attention. CHAIRMAN C. S. Cole 3That is true, the illustrations close at hand are the ones we often overlook.

Jan 1, 1945

By AIME AIME

A. A. Holland, Consulting Engineer, Toronto, Ont.-I noticed in this discussion of locations in which radium is found, no mention is made of the recent deposits discovered in Ontario. While radium is not a subject with which I am very familiar, I took an interest in this deposit on account of its novel occurrence. It is found in Haliburton County, near Wilberforce, Ontario, associated with a quartz free pegmatite, in a "break" that I understand can be traced for two miles. This "break" marks the contact between the limestone and syenite and contains numerous cavities or vugs. The gangue, on account of its deep purple, appears to :be amethyst.

Jan 1, 1930

By Sir Albert E. Kitson

The manganese ore deposits of the Gold Coast, British West Africa, occur in very ancient rocks, of both sedimentary and metamorphic types. In certain respects they have a strong resemblance to those of India and Brazil, as contrasted with those of Tertiary age in Georgia, but in this paper no careful comparison with them can be made. Viewed from the present condition of the manganiferous rocks, the oldest deposits are in the sediments. Later than these are the progressively metamorphosed representatives of these sediments. Youngest are the products of decay and degradation with the concentration of manganese oxide in the rocks of both groups. The oldest occurrences are in argillaceous and siliceous phyllites and slates, which show only a moderate degree of metamorphism. They belong to a series which also includes mudstones, sandstones, grits, conglomerates and subordinate limestones, with tuffs and lava-flows, largely of basic types. This has been named the Birrim System. Its age is unknown, for no definite fossils have been discovered in it. Since these non-fossiliferous strata at many plaees are of a character which in many parts of the world are suitable for the preservation of fossils, and which contain them, it is assumed that the Gold Coast deposits are pre-Cambrian. These rocks of the Birrim System have normally a northeast-southwest strike, and are folded, but not to any very great degree except in certain belts. From the Eastern Province of the Gold Coast they may be traversed diagonally across their strike for upwards of 600 miles, to the extreme northwestern corner of the Northern Territories. Thence they probably extend much farther into French territory.

Jan 1, 1927

Contribution by G. Narsimhan It was with much pleasure that I went through D.F. Malan's excellent paper. The following explanatory and critical note has been the result of my deep study of the paper. Although by qualifications and experience I have been a chemical engineer, involved over four decades with problems in the modeling and simulation of transport-limited (heat and mass) chemical reactions in multi-phase systems, I have of and on interested myself in challenging problems in extractive metallurgy. This is the first time I have veered of to continuum mechanics, at the age of 71! Author's reply. I thank Professor Narsimhan for his extensive contribution to the paper. It provided me with the stimulus to derive an extended model. However, there are some inaccuracies in his arguments that need further discussion. Professor Narsimhan's main concern is that there is not a good enough fit between the derived viscoelastic Kelvin model and the experimental data supplied by Güler1 (see Figure l1 on page 218 of my paper). I will therefore explain the choice of a viscoelastic model in more detail and also make specific comments on the arguments given in his contribution.

Jan 1, 1996

The theme i wish to develop in this talk is how we might make use of the scientific and technological knowledge we now have ofextraction metallurgy to meet the present-day needs of the production industry.Before doing so, I would like to say a few words in tribute to Dr. G.K. Williams since he was a past master at precisely what I wish to talk about. I knew G.K., as everybody called him, during the time he spent at Avonmouth in the late 40's and in the 50's. Later, when he was ostensibly retired, I had the pleasure several times of lunching with him when I was visiting Melbourne.When G.K. was at Avonmouth, the Imperial Smelting Process was in that capricious adolescent stage in between the pilot plant and the full-scale commercial unit. G.K. was a great collector of process plant data which hung in cascades from the walls of his office and-from his hand-operated desk calculator. What G.K. understood very well were the basic metallurgical and engineering principles of what was going on in the sinter machine, the shaft furnace and all their ancillaries.

Jan 1, 1985

By J. E. Brantly

In October 1939, a drilling program was commenced on the Atlantic seaboard of Brazil, with three steam rotary rigs of medium capacity. One of these was assigned to the State of Alagbas and the other two to the State of Bahia. During the remaining few months of 1939 and during the year 1940, some eight wells were drilled, two in Alagbas and six in Bahia. Two small producers were found in the latter state. In early 1941 three medium-weight Diesel rigs were added to the equipment, thus permitting the drilling of some 15 wells during the year 1941. The two small producers found in 1940 in the State of Rahia were near the city of Silo Salvador. In 1941 three additional small wells were brought in, in the same area, and a further producer on an isolated structure some 75 km. to the northwest of this production. No commercial production has been found in the State of Alagbas. Approximately 26 wells have been drilled or are drilling, six of which are producers— five in one area and one in another. The program for 1942 calls for the development of the two areas in which wells have been found and also the drilling of several wildcat structures located either by geophysics or surface geology. All production in the area of the several producing wells is somewhat less than 2000 ft. and in the other area about 3800 ft. The area of the several wells is known as the Lobato field, and is practically within the city limits of Sao Salvador. The area 75 km. northwest of the city will be known as the Candeias field.

Jan 1, 1942

By J. E. Brantly

In October 1939, a drilling program was commenced on the Atlantic seaboard of Brazil, with three steam rotary rigs of medium capacity. One of these was assigned to the State of Alagbas and the other two to the State of Bahia. During the remaining few months of 1939 and during the year 1940, some eight wells were drilled, two in Alagbas and six in Bahia. Two small producers were found in the latter state. In early 1941 three medium-weight Diesel rigs were added to the equipment, thus permitting the drilling of some 15 wells during the year 1941. The two small producers found in 1940 in the State of Rahia were near the city of Silo Salvador. In 1941 three additional small wells were brought in, in the same area, and a further producer on an isolated structure some 75 km. to the northwest of this production. No commercial production has been found in the State of Alagbas. Approximately 26 wells have been drilled or are drilling, six of which are producers— five in one area and one in another. The program for 1942 calls for the development of the two areas in which wells have been found and also the drilling of several wildcat structures located either by geophysics or surface geology. All production in the area of the several producing wells is somewhat less than 2000 ft. and in the other area about 3800 ft. The area of the several wells is known as the Lobato field, and is practically within the city limits of Sao Salvador. The area 75 km. northwest of the city will be known as the Candeias field.

Jan 1, 1942

1. New books P. Sarnoff. Trading in gold. Cambridge, Woodhead- Faulkner, 1980. 136 pp. £3.50 by airmail. Environmental Planning Professions Interdisciplinary Committee (EPPIC). Proceedings: Joint EPPIC/Habitat Symposium: Shaping Our Environment. Johannesburg, EPPIC (P.O. Box 61019, Marshalltown 2107), 1980. R3 per set of 2 issues. H. P. Patra and K. Mallick. Time-varying geoelectric sounding. Amsterdam, Elsevier, 1980. 420 pp. D.S. $87.75. Die Suid-AfrikaanseSteenkoolverwerkingsvereniging. Steenkoolvoorbereidingskursus. J ohannes burg, die Vereniging, 1930. 335 pp. Members of Chamber of Mines of South Africa R15, nonmembers R40. D. R. Derry. A concise world atlas of geology and mineral deposits. London, Mining Journal Books, 1980. HO pp. £26.25 byairmail. 2. Journal Remote sensing of environment (RSE). 3. NIM reports Report No. 2064 The on-line monitoring of gold in barren solutions. Report No. 2065 The determination, by X-ray-fluorescence spectrometry, of gold, silver, and base metals on activated carbon. Report No. 2068 The determination of platinum, palladiuim, rhodium, and gold in ores and concentrates by the fusion technique with lead as the collector. Report 2061 The determination, by anodic-stripping voltammetry, of copper and lead in silicate reference materials. Report 2062 The reduction by computer of photoplate data obtained by spark-source mass spectrornetry. Report 2071 The determination, by X-ray-fluorescence spectrometry, of tin and tungsten in scheelite and ca8siterite ores and concentrates. Tunnelling Tunnelling '82, the third international symposium in the series, is being organized by the Institution of Mining and Metallurgy, with the co-operation of the British Tunnelling Society, the Institution of Mining Engineers, and the Transport and Road Research Laboratory.

Jan 1, 1980

1. New publications International minerals/metals review - 1982. Washington D.C., McGraw-Hill, 1983.720 pp. U.S.$1l7. Mining subsidence engineering, by Helmut Kratzsch. New York, Springer, 1983.580 pp. U.S. $63,20. Papers presented at the 6th International Symposium on Jet Cutting Technology, Guildford, England: April 6-8, 1982, edited by H. S. Step hens and E. B. Davies. Cranfield (England), BHRA Fluid Engineering, 1982. £40. 2. Mintek reports Report M95 Modern applications of polarography and voltammetry to inorganic analysis. Report M96 The mathematical modelling of the reduction behaviour of chromite from the Upper Chromitite Layer of the Bushveld Complex. Report M113 The selective flotation of South African chromite. Conference on copper The International Conference 'Copper 83', to be held in London on 1st and 2nd November, 1983, will provide a valuable forum for all connected with the manufacture and use of copper. Underwater mining The 14th Underwater Mining Institute will be held in Madison, Wisconsin, on 7th and 8th November, 1983. Asian mining The Institution of Mining and Metallurgy, in conjunction with the Chamber of Mines of the Philippines, will hold an international conference, Asian Mining '84, in Manila, Philippines, from 6th to 8th November, 1984. Apcom '84 The Eighteenth International Symposium on the Application of Computers and Mathematics in the Minerals Industries will be held in London in the week 26th to 30th March, 1984. The Symposium is being Jet cutting Another Symposium on the very successful and popular series of international conferences on Jet Cutting Technology is being arranged by BHRA.

Jan 1, 1983

By D. J. Houlahan

ABSTRACT Sorting has the potential to massively improve the pro?tability of mining base metal, hard-rock ores. However, several barriers to the increased application of sorting have been identi?ed, including a lack of mineral-speci?c sensors available to the industry. This paper presents the outcomes of acollaborative project to develop an induction-balance sensor speci?cally for low-grade copper and nickelores. A review of the basic principles of induction-balance sensing and of the sensor-rock interaction is presented. Early development and testing of the sensor on ores from the Thompson nickel belt in northern Manitoba is discussed. Shortcomings of the prototype identi?ed in early testing have now been over-come, leading to improvements in design and construction, as well as sensor accuracy. The improve dsensor has now been tested on additional ores from the Sudbury Basin, with good results. A discussion of potential applications is presented and recommendations for future development are made.

Jan 1, 2010

By Raymond Sandiford, Kenneth Xu, Taehyun Moon

Tunnel approach structures situated in slow moving earth flows are subjected to significant earth pressures. The authors have developed a system, utilizing collapsible concrete columns, that limits such loading. The system uses an array of collapsible concrete columns in front of the structure to absorb downslope movement and limit-imposed loads. This concept has been modelled using 3D FEM analyses and a rudimental lab test. For implementation, the collapsible columns would be prefabricated in strengths to mimic the soil strength profile. This concept has merit, and analytical results demonstrate that collapsible columns are a viable means to limit loading.

Jun 23, 2024