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By P. Middendorp, Gerald E. H. Verbeek

"INTRODUCTIONStatic Load Testing (SLT) is generally considered the pile testing method that provides the de-facto answers regarding pile capacity and load-deflection behavior. However, as this testing method is time consuming and costly, alternative pile testing methods are applied, such as High-Strain Dynamic Testing (HSDT), commonly referred to as Dynamic Load Testing (DLT), and Rapid Load Testing (RLT), which includes Statnamic Testing (STN) and the Fundex Pile Load Tester (PLT). Extensive descriptions of these pile testing methods as well as comparisons of the results from these two methods have been widely published, but little is written on the choice between HSDT and RLT. This article will address this issue for concrete piles by discussing five different aspects that should be considered when making a choice between HSDT and RLT for either cast-in-situ piles or precast driven piles. TIMINGThe timing of the pile load test is independent of the testing method. For cast-in-situ piles load testing is performed some time after the pile has been installed (to allow the pile to obtain the compressive strength required to withstand the test load), while for precast driven piles load testing is performed after a so-called set-up period following pile installation (to allow the soil to recover from driving induced disturbances and, at least in most cases,regain strength).In other words, the timing of the test does not affect the choice of the testing method.ACCURACY OF THE APPLIED LOADWhen a pile is tested by RLT the applied load is measured by a calibrated load cell placed on the pile head, just as it would be during SLT. This means that the error in the applied load value is less than 0.1% of the maximum range of the load cell.However, when a pile is tested by HSDT the load is calculated from the measured strains, which means that the outcome is dependent on the pile material properties. In this case the applied load (F) on the pile head is calculated by multiplying the measured strain (?) with either the calculated or estimated elastic modulus of concrete (E) and the pile cross section (A).The elastic modulus is generally back calculated from the (average) stress wave velocity (c), which in turn is derived from the reflection time (T) it takes for a stress wave to travel over the pile length (L) from the pile head to the pile toe and back to the pile head."

Jan 1, 2006

By E. Barsky

"Theoretical notions of mass transfer processes in cascade separation of bulk materials have not been adequately developed as yet (Barsky M.D. 1980). In this paper we have derived linear difference equation of the second order for a cascade with initial feeding top any stage proceeding from mass exchange regularities. The solution of these equations has allowed us to determine quantitative dependences of the material distribution over the cascade stages, which serve the basis of the method of predictive estimate of the process results. We have also examined the model of the material distribution coefficient formation at individual cascade stages.We have checked the adequacy of this model to experimental data. It is noteworthy that the obtained theoretical results are phenomenological, i.e. they can be applied to the processes of separation of different physical nature, e.g. of isotopes, liquid media, gases, etc.INTRODUCTIONRecently, the processes of cascade separation of bulk materials have found broad application in various industries. They ensure a high separation efficiency and high-quality composition of final products. Although specialized literature gives serious attention to cascade processes [1], their theory is not sufficiently developed yet. To achieve optimal organization of this process, we examine mass transfer in a cascade gravitational classifier with stages of identical design."

Jan 1, 2016

By Ryan P. Sullivan, G. Alan Klevens, Jian Huang

"BACKGROUNDLake Hamilton in Hot Springs, AR was created in 1932 when the Arkansas Power and Light Co. completed Carpenter Dam on the Ouachita River to generate electricity. Today, the 7,200-acre (2,914 hectares) impoundment is one of Arkansas’s most popular recreational and residential lakes.U.S. 70 crosses Lake Hamilton by means of a seven-span bridge featuring nine steel girders per span. Constructed between 1982 and 1984, the 1,410-foot long (430m) bridge carries four lanes of traffi c across the lake. The bridge is supported by six intermediate reinforced concrete piers composed of hammer heads, stems, footings and seals, which sit on the underlying rock. (See Figure 1). The bridge rises to a maximum of 33 feet (10m) above the surface of the lake and the footings and seals extend a maximum of 29.5 feet (9m) below the surface of the lake. The seals are situated on hard, fractured sandstone and shale. Routine underwater inspections in 1993 revealed large cracks in the lean seal concrete and reflective cracks in the reinforced concrete footings. Infrastructure Engineers, Inc., The Arkansas State Highway and Transportation Department’s (AHTD) design consultant, then conducted an in-depth underwater inspection of the pier foundations. The investigation included cross-hole sonic logging, singlehole sonic logging, visual examination and strength testing of core samples, and petrographic analysis.The investigation revealed extensive cracking and low-strength concrete within the seals of all intermediate pier foundations. Many voids within the seal concrete had become filled with silt. There was evidence of continued seal deterioration between underwater inspections.AHTD and its engineers considered three rehabilitation solutions in the preliminary engineering stage: micropiles, a cofferdam supported concrete jacket, or a pile supported concrete jacket. The three alternatives were estimated to cost $1,250,000; $4,320,000; and $3,030,000 respectively. All three options would transfer the loads from the pier footing directly to the rock below, bypassing the seal concrete."

Jan 1, 2007

By Alan M., Bateman

MR. JORALEMON'S dispassionate discussion of this subject in TECHNICAL PUBLICATION 340 of the Institute shows clearly some of the failures and successes of geology in the discovery of ore deposits. He forces us to recognize, with humility, that chance has played a greater part than geology in the recent discovery of several great copper deposits. I think, however, he wrongly ascribes to unexpected or chance discovery some deposits that were found as a direct result of geological investigation. I refer to the Rhodesian copper deposits,, particularly Roan Antelope and Mufulira, both mentioned by him as having been found by chance. Also,. I think Mr. Joralemon's paper, inadvertently, does not- give the proper credit for the early recognition of the possibilities of these deposits. I feel sure that Mr. Joralemon and the gentlemen given credit by him will welcome any further information on this subject that will throw light on what will some day- be of. historical interest and importance. Consequently, I should like to set forth some additional data that throw light on who should receive the most credit, and' to indicate that, in my opinion, sound. geological reasoning and not chance is to be, credited for the development of the. Roan Antelope and Muf ulira mines.

Jan 1, 1931

By Matias Suarez, Diego Zenteno

This paper is aimed to display the new advancements of blasting engineering done in different mining sites throughout the country, associated to electronic sequencing, energy of the explosive and its impact on the fragmented rock. This document explains how to define and implement selective sequencing in the blasting in order to promote the propagation of cracks, therefore impacting positively the productivity through the use of the LaGrange diagram. The LaGrange diagram is a very convenient and illustrative method to present the dynamic behavior associated with wave and crack propagation (Rossmanith. H, 2002).

Feb 1, 2020

By Robert McClure, Carlton Lehman

Rendering safe explosives in an urban environment presents a unique challenge due to the safety concerns and disruption to the general public. Potential damage to the surrounding homes, businesses, utilities and transportation infrastructure are some of the major concerns when planning the render-safe operation. Engineering controls to mitigate blast effects, such as damaging air over pressure levels, material ejection and ground borne vibration, need to be implemented as part of the operation. Monitoring of seismic and air overpressure during these operations are needed to protect against potential claims when controlled or unplanned detonations occur.

Feb 1, 2020

By Javier Castaneda, Luis Zozaya, Noel Huarachi, María Rocha

The objective of the project was to implement and calibrate drill and blast models supported by Geotechnical and Geological models as well as the mine and operation characteristics. The models would then be migrated to HxGN Blast to ensure a productive process that is simplified, digitized and optimized.

Feb 1, 2020

By Frank Hirthammer

Since the introduction of the Explosives Track & Trace in Europe in 2014 for manufacturers and 2015 for end-users, a lot has changed in all areas of the supply chain and the use of explosives. The regional associations, manufacturers' organizations, and trade associations have proven that it is possible to overcome a hurdle, that looks almost impossible in the beginning, through consistent cooperation. The paper gives an insight into the problems involved in introducing such a requirement, identifies ways and solutions, and concludes them. When looking at the current situation, the paper describes the process by which a prescribed change in business processes are transforming into a solution that increases productivity, security, and handling.

Feb 1, 2020

By J. A. Russell

MR. M. W. Boom: I would like to congratulate Mr. Russell on his fine paper. One very good point which has always appealed to me is the smooth working of a steam hoist as compared with electrical. He does not mention the steam hoist at Springhill which has been working there for a good many years. MR. S. R. NEWTON: I have read with a great deal of interest the paper presented by Mr. Russell on the development of haulage engines in the mines of the Dominion Steel & Coal Corporation. He is to be congratulated on having produced a comprehensive article showing, step by step, the various improvements that have been made over the years in the design of such engines. I am quite in accord with Mr. Russell's statement that the positive tooth clutch can have too many teeth, and also that the method of driving a sliding clutch hub of any design should be by means of a hexagon or octagon on the shaft. Where the clutch hub does not of necessity slide on the shaft it can be pressed on and keyed to the shaft in the normal manner. With regard to the 'Cramp' internal-expanding jaw-type clutch, while it is true there are more moving parts than with the clutch consisting of a ring with internal cut teeth and a driver having a fewer number of teeth as .described by Mr. Russell; there are compensating advantages to the internal expanding jaw-type of clutch. The V shaped profile of the teeth permits of engagement of the clutch with very much less 'jockeying' of the drum. This is particularly the case in vertical-lift mine hoists, where it may be necessary to engage and disengage the clutching mechanism at frequent intervals.

Jan 1, 1944

By S. W. MEALS

TWENTY million people in this country and Canada in nearly four million homes can give thanks to our Creator for natural gas, that most wonderful natural fuel with which Dame Nature has so bountifully blessed us. It is a clean, healthy and cheerful fuel, made up almost entirely of carbon and hydrogen. There is no residue, no waste and there are no objectionable constituents; an ideal fuel for the home. It operates like magic, open the valve and it is there for your needs, winter or summer, night or day. You are not required to place your order 30 to 90 days in advance and you do not need to pay for your winter's supply in advance. No ashes to worry about, no flues or chimneys to clean, nor kindling wood to store or bother the housekeeper. We who have been so blessed do not realize what it would mean to be without it. If in place of opening a valve we had to go to the woodshed or coalhouse and then build our fire-carry out the ashes-well, some of us I am afraid would be late reaching our offices and perhaps would miss our hot cakes for breakfast. One cubic foot of gas produced from the White Sand formation contains 1130 B.t.u. and weighs 47/1000 lb.; there are about 24,000 B.t.u. in 1 lb. of gas. Temperatures of over 3400 deg. Fahr. have been obtained with natural gas. Not only is it a superior fuel for the home but it has no equal for use in many large manufacturing industries, especially with the making of glass, pottery and open-hearth steel. In an open-hearth furnace, properly constructed, 5000 cu. ft. will melt one ton of steel. It requires 1/3 ton of bituminous coal gasified in a producer to do the same work, or about 40 gal. of tar or fuel oil, or 11,000 cu. ft. of by-product gas.

Jan 1, 1926

By AIME AIME

INDUSTRIAL Pittsburgh, the center of the coal and iron and steel industry of the world, was host to the Coal Division at its Fall Meeting held there on Oct. 21 and 22 at the William Penn Hotel. The past year has witnessed remarkable progress in new methods of mining and burning of coal and many of the papers on the program discussed these developments. Nearly 100 had registered at the time of the first session on Wednesday morning and this number increased to 168 on Thursday. Owing to the large number of papers on the program, eighteen in all, it was necessary to hold group meetings on Thursday morning, with a capacity attendance at each meeting. . Chairman McAuliffe was on hand early Wednesday morning to open the meeting. George Otis Smith, representing President Lovejoy, came over from Cleveland where he attended the meetings of the Institute of Metals Division. Secretary Parsons arrived later from Cleveland and spent the whole morning with the executive committee of the Division. Doctor Smith, Secretary Parsons, and J. T. Breunich were the official representatives from Institute headquarters.

Jan 1, 1936

By SANDVIK WHITE

The mining industry produces approximately 4-7% of global greenhouse gas (GHG) emissions. It is fundamental for mining operations to take immediate sustainable action to actively contribute to an emissions-free future for the next generations. The mining industry has traditionally relied heavily on diesel technology and transitioning to more sustainable solutions requires change management to drive cultural acceptance and new product development. Sandvik was interested to find out the lifetime emissions of a single drill rig and to compare similar application diesel and BEV drill rigs with same use profile to each other. That led the calculation and pondering towards comparing different countries and mine sites as well

Jan 1, 2023

By Thomas Pea, Heiner Kontrus, Jérôme Steinkühler

In tunnel condition assessment, the trend is towards comprehensive 3D measurement combined with high quality image texture to document and quantify damages to the tunnel surface and to create a cohesive data base of the structural conditions throughout its lifespan. The faster such measurements can be made on site, the less it impacts traffic conditions of the highly sophisticated subway systems. The Dibit high-speed 3D scanning system which is based on Photogrammetry and LiDAR technology enables data acquisition in tunnels at a speed of up to 60 mph. Given the high rate of speed the system can operate, tunnel shutdowns can be drastically reduced, and tunnel safety increased. The photorealistic texturing of the 3D-model allows the identification and analysis of smallest material damage (e.g., cracks ≥0.3 mm wide). The publication illustrates technical details and 3D results of the innovative system from measurements that were performed in the subway tunnels of the Bay Area Rapid Transit System in San Francisco, CA (total length 66.23 km).

Jun 13, 2021

By Karin Bäppler

Lyon with half a million inhabitants is the third largest city in France. Urban agglomerations such as Greater Lyon demand intelligent underground solutions for the freedom of mobility of its inhabitants. The city and metropolitan area of Lyon provide an example of a city strategy adapted to the changing needs due to demographic and living standard trends. The Lyon Metro Line B with a length of 2.4 km is one of the strategic projects with regard to city planning and future mobility. The paper will highlight on this special area of application in singular diverse geology with sophisticated mechanized tunnelling technology.

Jun 13, 2021

By Joseph Jensen

THE history of the normal oil field is supposed to show an oil graph stalting high in flush production, descending more or less steeply into the curve of settled production and dropping gradually to the vanishing point of economical operation. Together with this at somewhere in the early history of the field, there appears from a vanishing point a graph showing the production of water. During the period of settled production this graph rises higher and, toward the close, unless extensive work is done in the line of correction, rises far above the oil graph to where the cost of operation terminates profitable pumping. Fields that start out with a high relative content of water are generally very short lived. Fields that never develop a water problem are exceedingly rare.

Jan 1, 1930

By Jason Rock, Rob Thompson, Lee Julian

This paper presents an innovative shift in inhibited bulk products with specific reference to their manufacture and application.

Feb 1, 2020

If a fire occurs outby an underground coal mine section, the immediate safe evacuation of miners from the working section should always be the first action during the rescue operation. Unfortunately, in many cases, the escape-ways (escape routes) dedicated for miners' evacuation are contaminated with fire byproducts from adjacent entries. The purpose of this paper is to present the ventilation control process that will maintain the escape-way free from contaminants and available for travel. Several scenarios in a different section on ventilation system arrangements are analyzed, discussed and presented. To perform these studies, the author used a mine-fire simulator, which provides a dynamic (in real time) representation of the fire's progress and also gives a display, a color-graphic visualization, of the spread of combustion products throughout the ventilation system. Presented and discussed in this paper, also, are ways in which the mine-fire simulator can be used as a training and teaching tool for miners and, particularly, for ventilation and safety personnel.

Jan 1, 1993

By Arthur S. Dwight

THE professional career of Thomas Septimus Austin, who died at El Paso, Tex., August 23, 1906, was contemporaneous with the growth of the silver-lead smelting-industry of the Far West, to which his talents and zeal contributed in no small degree. Born at Stratford, Conn., December 7, 1853, he was the seventh son in a family of thirteen. His parents were well-to-do; and he received a thorough preliminary training at the Hopkins Grammar School, New Haven, Conn., passing thence to the Columbia School of Mines, in New York, where he was graduated in 1876. His first professional work was that of analytical chemist with a Cuban sugar company. In this position he spent a year, and, whatever else of benefit he may have acquired during that year in Cuba, he gained a facility of speech in the Spanish language which was of inestimable value in his subsequent work in Mexico and the southwestern United States. In 1877, he went to the Rocky Mountains, and, under the firm name of Murphy & Austin, opened an assay-office in Leadville, Colo., which was just then coming into public notice as a rich silver-lead camp. The next year, however, he entered the service of the Germania Smelting & Refining Co. at Salt Lake City, Utah, where he remained until 1882, first as assayer and chemist, and later as Assistant Superintendent. The Germanic bears the honorable distinction of being one of the first of the large " custom " lead-smelters erected in the West. Its founders may be called the pioneers of the modern lead-smelting practice, and the Germania served, to a large extent, as a model for the many plants that sprang into existence during the next few years in Utah, southern Idaho, Colorado and other lead-producing districts. The formulation, for the first

Jan 1, 1908

By Tyler Rockley, Cara Rosen

Blasting at a granite quarry in eastern Maryland produces elevated air blast readings that can fall into the cautionary zone for the state of Maryland environmental regulations on a semi-regular basis. When designing blast patterns in this quarry, challenging geology creates rough and uneven blast faces that can be difficult to capture with 2D laser profiling fully. Utilizing several methods known to manage high air blast results like pattern adjustments, decking, and timing changes have not achieved consistent outcomes.

Feb 1, 2020

By Albert F. J. Bordeaux

Discussion of the paper of Albert F. J. Bordeaux (Bi-Monthly Bulletin, No. 23, September, 190S, pp. 629 to 640). A. H. BROMLY, Zihuatanejo, Guerrero, Mexico (communication to the Secretary*) :-The following criticism of what "is offered as a summary which may be found useful by mining engineers," is not dictated by any captious spirit, but in the interest of historical and scientific accuracy. The States of Queretaro and Oaxaca have produced sufficient silver to warrant more extended notice. Referring to Pachuca, State of Hidalgo, the somewhat loose and. inexact statement is made that "the ore-deposit is an andesite, intermixed with quartz-veins, rich from the surface." A better description would be,-the ore-deposits consist of quartz-veins in andesite. It is notable that many of the rich shoots worked in recent days did not come to surface. In consequence, Pachuca, is often quoted by the ill-informed as a camp in which values improve with depth, the truth being that the veins carry shoots, or clavos, some of which were exposed at surface and some not. The name of " electric plow," applied to the mechanical stirrer of recent use, is certainly not to be recommended. The stirrer, or agitator, consists essentially of a traversing gang-plow, operated by power through shafting, drums, and wire-rope. The fact that in certain plants the motive-power used is electricity does not make it an electric plow. Such a name suggests a machine of which the motor is an essential and integral part; which is not so in this case. A lathe in a factory driven by water-power is not called a hydraulic lathe. My experience agrees with Dr. Raymond's note as to azulaque, which in sortie districts is also applied to blue copper carbonate. The El Oro, Esperanza, and Mexico mines should be allocated to the State of Mexico; the Dos Estrellas being in Michoacan, as stated. The El Oro quartz certainly does not appeal to me

May 1, 1909