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By Armin W. Stuedlein, Youssef Bougataya

Early stage design of driven piles primarily relies on static analysis based on one or a combination of total and effective stress approaches, the latter known as the method to estimate axial capacity. A database of 85 piles driven in the Puget Sound Lowland region and monitored at End of Driving (EOD) and Beginning of Restrike (BOR) was compiled along with capacities estimated using the CAPWAP procedure. Established soil profiles based on borings with standard penetration tests (SPT), cone penetration tests, and geologic maps were matched with their corresponding unit shaft resistance profiles from the CAPWAP procedure and resulted in more than 1,200 observations. In this study, eight new models were developed to predict the coefficients at EOD and BOR, based on the corresponding USCS categorization. Each coefficient model is formulated using a three-parameter exponential function, calibrated to capture the profile of coefficients with depth. These models could benefit the designer by providing them with a simple, empirical model that accounts for soil type and setup in a smooth, continuous function with depth. A parallel analysis was performed to assess the accuracy and variability of the formulated prediction models to facilitate implementation in load and resistance factor design (LRFD). INTRODUCTION The design of the axial capacity of driven piles during the planning stages of a project is typically based on a static analysis approach. The goals of this approach are to predict the components of capacity, consisting of the shaft and toe bearing resistances, and to assess project concept feasibility and preliminary lengths. In most cases, this analysis is based on empirically-developed methods, such as the total stress method, also known as the method (Tomlinson 1987) or the effective stress method known as the method (Esrig and Kirby 1979; Fellenius 1991). Many other methods, such as those based on in-situ test results exist and rely on correlations of blow counts from the standard penetration test (SPT), and cone tip and sleeve friction resistance from the cone penetration test (CPT), to shaft and toe pile resistances (Schmertmann 1978; Meyerhof 1976; Nottingham and Schmertmann 1975; Nordlund 1963; Eslami and Fellenius, 1997; De Ruiter and Beringen 1979). Although these methods were generally developed using data from specific geological regions, they are often recommended in national design manuals (e.g., FHWA, Hannigan et al. 2006).

Jan 1, 2018

By Loren R. Anderson

This is an Appendix of Volume I. In contains the results of the electric cone penetrometer soundings from the second phase of the testing program.

Jan 1, 1982

By M. M. Fine

Research on the solid-fuel reduction of Knob Lake iron or was conducted to upgrade lean and high-grade ores and recover metallized products suitable for ironmaking or steelmaking. The program included bench-scale tests plus a number of continuous campaigns in a 34-inch by 36-foot rotary kiln. In the laboratory, metallizations in excess of 90 percent were achieved by reduction of crushed ore with lignite at 950° C. Subsequent grinding (to minus 200 mesh) and wet magnetic separation yielded concentrates analyzing less than 3.0 percent SiO2 and more than 90 percent Fe. Virtually complete recovery of the iron occurred. During early continuous tests the crushed ore created a serious ringing in the kiln which was solved by balling the fines with bentonite. Unfortunately, at this temperature (950° C) the bentonite militates against the concentratability of the metallized product. For example, a run on direct-shipping ore produced concentrates of 89.5 percent Fe and 4.5 percent SiO2. At 500° C the adverse effect of bentonite disappeared and concentrates of 88.4 Fe and only 2.5 percent SiO2 resulted. However, with comparable feed r Los, the metallization dropped to 73 percent.

Jan 1, 1969

By Axel Doelcken

?? Liebherr excavators in standard configuration are generally designed to operate in an ambient temperature range between -12°C and +55°C (10.4 °F and 131°F). ?? To operate effectively and efficiently in very low temperatures special consideration needs to be given to the design ??An inappropriately designed hydraulic system unable to withstand extreme changes in temperatures or varying working conditions will lead to: - premature wear and more frequent replacement of components - increased maintenance & unplanned downtime This will affect productivity & operating costs.

May 1, 2008

By Maurice Bottiau

The recent evolution of the piling market clearly shows a growing demand for screw piles with soil displacement. The recently developed Omega Screw pile ful-fill these new expectations, combining the advantages of vibration-free systems and the behaviour of a displacement pile. The paper describes recent experience and new applications with this very promissing pile. Full-scale load tests were carried out in different countries as U.K. or Sweden. A very attractive and innovative piled embankment is also described, using geogrids in order to transfer the loads from the superstructure to non-reinforced Omega-piles.

Jan 1, 1996

By Tuncel M. Yegulalp

The objective of this study was to categorize mining operations in the stone, and sand and gravel industries into areas of similar ground control functions and define initial factors affecting operational safety in each area, by means of utilizing publicly available data, telephone interviews and on site observations. The findings and recommendations presented in this report are based on the information collected during the two phases of the project. They also contain, in part, the collective qualitative opinion of the operators with respect to government rules and regulations on ground control safety and the implementation of these rules and regulations by government inspectors.

Jan 1, 1981

By D Craw

Formation of gold-bearing veins in Otago Schist was intimately linked to the structural evolution of the schist belt. The currently-exploited Macraes gold deposit formed in a regional scale shear zone during latemetamorphic uplift of the schist belt. Further exploration for this type of deposit will be facilitated by an increased understanding of the late-metamorphic structural evolution of the schist belt. To this end, a three-dimensional cross section through the Otago Schist has been drawn using structural data gathered at outcrops in a 20 - 40 km wide transect across central Otago. This is the first continuous detailed structural section to be drawn through the belt. The section spans an area from Textural Zone 1 metagreywacke of the Torlesse terrane in the northeast through TZ 4 schist in the central region and across the Caples-Torlesse boundary to Textural Zone 3 schist of the Caples terrane in the southwest. Two different late-metamorphic structural generations are identified in this section: the long-recognised Manorburn Generation, and a new æPoolburn GenerationÆ. The location of the Caples-Torlesse boundary has been refined on this transect by field mapping combined with whole rock geochemistry.

Jan 1, 2001

By P. R. Desam, J. D. Miller, A. Datta

The flow behavior of bubble-particle aggregates in separation tanks is important for many flotation systems, particularly for wastewater treatment. These aggregates can be considered as the dispersed phase in a continuous liquid phase of water and the flow characteristics determine the efficiency of the bubble separation process. In this work, a general methodology for the computational fluid dynamics (CFD) simulation of a bubble separation tank is described. This system is analyzed by Eulerian-Lagrangian approach. The momentum transfer from the dispersed phase to the continuous phase is quantified using the Particle-Source-In Cell (PSI-Cell) method. With CFD simulations, the effectiveness of different tank design parameters are evaluated in terms of the extent of bubble separation.

Jan 1, 2000

The National Institute for Occupational Safety and Health (NIOSH) conducted a monitoring field study to optimize the rib control plan in a room-and-pillar coal mine. The study mine is located in the Central Appalachia coal basin. Two monitoring sites were selected at different sections in the study mine. The selected sites have different overburden depths and geologies. The instrumentation plans at study sites include borehole pressure cells installed at various depths in studied pillars, rib and roof extensometers and load cells mounted on number of the rib bolts. The instrumentation results and observed geology for one of the study sites showed great potential for optimizing the rib bolt plan at that section of the mine. Therefore, a rib support optimization study was followed using numerical modeling technique. A calibrated threedimensional model was developed using the instrumentation results of the optimization section. The calibrated model was used to determine the optimum rib support for expected overburden depths and rib heights. Baseline rib bolt patterns were assumed for the optimization study. Additional rib bolts, above and beyond the baseline bolting parameters, were outlined and identified as solutions to contain the rib fracturing identified by the modeling results.

Jul 28, 2020

By G. D. Andria

Contract J0275007 was to consist of a thorough two-phase statistical analysis of respirable coal mine dust data from USBM Contracts H0232061, H0232060, H0230029, H0230031, H0210050, and H0242013. Consequently, BCR cataloged and assembled relevant data items from these contracts and formulated procedures suitable for the evaluation. The selected procedure was a Multilinear Regression Analysis which related dust concentrations measured in the mine to other mine parameters. Under the first phase, a thorough analysis of the date from USBM Contract No. H0230029 was completed. Primary results from this analysis are as follows: (1) The five variables that significantly affect dust concentrations in the return behind the brattice are the spray system utilized; the distance from the face to the return brattice; the return airflow; the production rate; and the water consumption rate, in that order. These five variables describe about 85 percent of the total variation in the return dust concentration. (2) Results at the miner and jack-setter locations were somewhat less conclusive due to the fact that only 17 percent of the variation in dust at the miner could be resolved and only 48 percent of the variation at the jack-setter location could be explained. The decision of the sponsor was that these initial results revealed as much information as could be expected; thus, per instructions from the USBM, the second phase (analysis of the other five contracts) was abandoned.

Jan 1, 1978

By C. Pelley, S. Kelebek, G. Kunzel, S. Gregersen, M. Pollanen

A series of small-scale tests was conducted to evaluate the effect of micro-fracture development, imposed by blasting, on the material properties of the rock as well as its resistance to crushing and grinding. The uniaxial compressive strength, tensile strength, Poisson’s ratio, Pwave, S-wave velocity, point load test index, crushing, and grinding work indices were evaluated for samples without any blasting load and for samples which had received a variety of blast loads ranging from a single impact with a lowstrength detonating cord to a combination of impacts at different times and significant impacts with powder factors close to those used in practical blasts. It was shown that the rock mechanics parameters change even at low impacts, suggesting easier crushing of the rock. Damage values appear to be affected by timing as stress wave superposition affects the damage process. Fragmentation is achieved at higher impact levels while work index modification of the fragments is also observed when high powder factors are used, suggesting improvements in grinding.

Jan 1, 2006

By Paul Downing

Identity Theft Outline • What Are MY Chances??? • Types Of Thefts • Sources Of Theft Info • Stolen Identity vs. Background Checks • Information/Data Safeguards • Corporate Data Handling • Reclaiming Your Identity • Monitoring Your Identity

Jan 1, 2006

By J. C. Thornley

Service failures of seemingly conventional galvanized bolts, in normal operation, on transmission towers in New Brunswick have been found to be the result of hydrogen cracking. In both these cases, similar failures elsewhere can be avoided by suitable clauses in the purchase specifications. In the first case described, the manufacturing procedure was responsible for strengthening and embrittling a standard, soft, constructional steel. In this case, a fracture mechanics analysis predicted critical crack depths for final fracture very similar to those found in practice. This case reveals an apparent cooperative connection between hydrogen embrittlement and strain ageing in plain carbon steels. In the second case described, the steel was simply a high strength steel which should not have been made into galvanized bolts.

Jan 1, 1979

By Mark Aylmore, Guy Deschenes

"Increasing pressure are motivating the gold mining industry to develop a substitute to cyanide for leaching gold. This effort in mainly based on the high toxicity of cyanide and on the lack of efficiency of cyanide in the treatment of mildly refractory gold ores (sulfides and pre-robbing). Consequently, in only a few years, consortia have been created to elucidate and implement a new technology. The most promising lixiviant that has been selected to replace cyanide is thiosulfate. This paper will present a critical analysis on the latest developments in thiosulfate leaching and illustrate the potential and limitations of the technology with experimental data. Finally an assessment of the cost and performance of thiosulfate leaching relative cyanidation will be evaluated.INTRODUCTIONConcerns regarding the toxicity of cyanide and inability of cyanide solution to effectively leach some carbonaceous gold ore or mild refractory gold ores have made the gold mining industry evaluate alternative lixiviants to leach gold. This concern has been heightened recently by the cyanide spill at a mine in Romania, which devastated a 250-mile stretch of the Danube River and its tributaries, and the environmental damage at Ok Tedi mine in Papua New Guinea. Some countries and locations have prohibited the application of cyanidation to recover gold, such as, California and Colorado States, Japan and Turkey etc.There are several potential non-cyanide lixiviants (Sparrow and Woodcock, 1995) for gold extraction, such as thiosulfate, thiourea and halogen. A pilot feasibility test (Marchant and Broughton, 1987) had suggested that thioureation might result in acutely toxic byproducts even after treatment. Scientists of Swedish Academic of Sciences reported that thiourea is a carcinogen. Halogen is also a pollutant to the environment. Thiosulfate leaching appears to have very good potential as an effective and less hazardous procedure for gold and silver extraction from auriferous ores. In addition to being much less toxic and relatively cheap, it forms a stable anionic complex with gold but is less reactive to other metals, for instances, copper and carbonaceous materials, in comparison with cyanide."

Jan 1, 2001

By G. L. Fitzpatrick

A portable optical instrument for performing multispot laser vibrometry is described. The instrument is capable of measuring arrival times, surface motion frequency, and surface velocity and displaying these quantities in various useful ways. Sigma Research is currently pursuing the development of such optical measuring systems for the evaluation of structures in rock by non-contact interferometry methods. This work was sponsored by the U.S. Department of Interior (U.S. Bureau of Mines) under a Small Business Innovation Research (SBIR) contract number J0145075. The goal of the work was to develop a portable tripod mounted measuring system which can be set up at arbitrary distances (up to 30 meters) from a surface and project four in-line laser sample beams on this surface. A light receiving telescope gathers the scattered light from these four spots and provisions are made to mix this light with a reference beam from the laser. Four photodiodes are employed to determine the resultant interference signals which characterize the motion (particle velocity, frequency, amplitude) of the four illuminated spots on the surface under sudy. Information of this type can then be used to characterize the elastic or mechanical properties of the surface in question. In some cases (if more than four spots are involved) this surface information could be back propagated to draw inferences about the internal state of the material volume bounded by this surface.

Jan 1, 1987

By Bjöm Böhle

Top-down construction (or cut and cover construction) is providing important advantages when comparing with conventional construction techniques for commercial developments with deep basements, underground car parks or near surface infrastructure and traffic tunnels. Main features are substantially reduced restrictions to surface usage, avoidance of intervention with adjacent property, provision of rigid substructures resulting in minimal deforma­tions and settlements and, last but not least, accelerated construction pro­gramme. The present contribution illustrates the construction method in general and elaborates in detail on the special foundation works for a major urban commercial high rise development requiring a six level basement structure.

Jan 1, 2006

By Kent von Maubeuge, Charles R. Landis

The global bentonite industry is a dynamic market balancing a range of end uses with an ever growing number of bentonite producers. In addition, markets in developed countries are elevating the level of detail and transparency for materials reporting in programs, such as the Registration, Evaluation, Authorization and restrictions of Chemicals (REACH) program in the European Union. Bentonite is impacted by programs of this nature. The majority of the bentonite products sold around the world are sodium bentonites. These sodium bentonites consist either of natural sodium bentonites, or naturally occurring bentonite dominated by divalent interlayer cations (Ca+2 andMg+2) subsequently exchanged with sodium cation. The latter variety is often called “sodium-activated“, or “soda-ash treated” bentonite. Once exchanged with sodium, these bentonites are often difficult to distinguish from natural sodium bentonites using common commercial testing protocols. Due to their similar colloidal and bulk chemical properties; the lack of test procedures designed specifically to identify this product feature; and the failure to completely or effectively explain their differences, sodium-activated bentonite is often considered to be identical to natural sodium bentonite in the industry. This article defines both general types of sodium bentonite and presents a technique that could serve the industry as a tool to confirm the variety of sodium bentonite in question. Specifically, geochemical properties such as carbon (C13/C12) and oxygen (O18/O16) isotopic ratios can distinguish activated, even slightly activated bentonites, from bentonites not introduced to additional sodium during manufacture.

Jan 1, 2004

By C. Sun

The Leeville underground mine has been in operation since 2006 and currently produces 3,200 tons of ore per day with an average gold grade of 0.4 opt. The mine has a large horizontal extent of 2,500 feet by 500 feet and a vertical extent of 20 to 200 feet. High density of joints occurs within the host rock. Based on Rock Mass Rating and field observation, the Leeville ground conditions are characterized as poor to very poor. As such, heavy ground support is required for the mining operation in Leeville. Ore zones with a height in excess of 10 m (35 feet) are considered for longhole stoping. A typical stope measures 6.0 m (20 feet) wide, 30 to 55 m (100 to 180 feet, depending on the ground conditions) long and 10 to 30 m (35 to 100 feet, depending the thickness of ore body) high, yielding 10,000 to 20,000 tons when completed. Narrow ore zones, less than 10 m (35 feet), are mined using cut and fill. These drifts are 4.6 m (15 feet) wide by 4.6 m (15 feet) high. Based on the afore-mentioned poor ground condition, the establishment of a ground control monitoring system is key to operating both safely and successfully. The ground control monitoring system is composed of comprehensive instrument design and installation. Instruments include Multi-Point Borehole eXtensometers (MPBX) and Stretch Measurement to Assess Reinforcement Tension (SMART) cables. The monitoring system covers the mining zones and infrastructure openings. After about two year?s applications and measurements, useful data has been and continues to be collected to use in future stope and infrastructure structure design. The system provides the information making engineer and operation teams to do their job more confident and efficiency. Keywords: Ground control, Monitoring system, Long hole stope, Instrumentation.

Jan 1, 2009

By H. J. Gerritsen

From presently available components a portable, rugged, reliable apparatus can be built which will be able to detect methane concentrations of 0.1% and lower in air. Sensitivity and design considerations of the apparatus are given. Ways to build even simpler and cheaper apparatus in the future are indicated. Traditionally the problem of detecting and monitoring the presence of dangerous gases present in small concentrations in air has been a difficult one. Whether canaries,' or sophisticated chemical or thermal conductivity methods are used, they seem to be either slow, cumbersome, or otherwise not completely satis factory. A seemingly natural way of gas detection is to measure the strength of absorption undergone by light of a wavelength that the gas to be detected absorbs. This method has been difficult to apply in view of the low power output over a narrow wavelength range in the infrared from traditional glow bar light sources. Besides, the apparatus to select such a narrow band of wavelengths is quite costly and complex. The use of a laser solves these problems simultaneously. Although a variety of lasers are available to detect a variety of gases (such as carbon monoxide or methane) whose early detection would be desirable, this paper deals exclusively with the use of lasers for methane detection. ABSORPTION SPECTRUM OF METHANE IN AIR The absorption spectrum of pure methane is very well known.2-4 There are four fundamental vibrations, all occurring in the infrared of which only two absorb strongly. They occur at 3.3 µ and 7.7 µ. The absorption spectrum is quite complicated due to the fact that the methane molecule can rotate in a variety of rotational quantum states. These rotational states are furthermore split by anharmonic forces such as the Coriolis force.4 When methane is present in air at atmospheric pressure, much of the very fine structure due to the anharmonic force is washed out since the pressure broadening is of the same magnitude as the splitting due to anharmonicity. For most of the spectrum at 3.3 µ, the rotational lines are typically separated by 0.01µ while the individual linewidth is 0.0001 µ. It is thus very important that the laser emit at a wavelength that coincides with one of these rotational lines. Before elaborating on the point that such a laser exists and how it performs, it is necessary for later discussion to point out that in the

Jan 1, 1967

By Frederick H. Raab

A power-line proximity-warning (PLPW) system must have a high probability of detection (alarm activation at a specific distance), low probability of false alarm, and minimal set-up and maintenance. Tests of electric-field sensors have not demonstrated a dependable alarm distance. Alternative sensing methods such as microwave radar, optical radar, and sonar can meet the requirements by direct measurement of the range from the boom to the power line. Suitable microwave techniques include RF pulse, chirp FM/CW, and baseband pulse. Baseband-pulse radar has adequate range capability and does not require expensive microwave components. The radar cross section of a power-transmission cable is adequate for its detection optical-radar systems based upon LEDs and photodiodes are inexpensive, but can achieve only marginal performance in this application because of their limited modulation bandwidth. Since laser diodes and cryogenically cooled photosensors must be used to achieve the desired range resolution, the cost of an optical-radar system is greater than that of a microwave radar system. Sonar systems are feasible, but are not as precise and cost at least as much as baseband-pulse-radar systems. The performance of both optical-radar and sonar systems is degraded by dirt, necessitating the inclusion of a "windshield wiper.' Baseband radar appears well suited to the PLPW application. The cost of a baseband-pulse radar PLPW system is expected to be comparable to that of an electric-field PLPW system. Development and testing of an experimental model are therefore recommended.

Jan 1, 1982