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By Tom A. Armour

Different variations of soil nailing techniques have been used in the United States since the late 1970's. Such techniques owe their origins to French developments, which began in the early 1970's as a spin-off from European tunneling excavation support practice. The growing demands of urban infrastructure development and rehabilitation and environmental protection have created an active and expanding soil nailing market demand for earth retention and slope stabilization in the United States since its early developmental years. There is a clear need for a fundamental review of the large number of soil nailing techniques that are currently being used in the United States. Following a brief summary tracing the historical development of soil nailing and a generic classification of applications, this paper provides a review of the different recent advances in the design and construction of soil nailed systems. Discussion topics include nail design advances, permanent "top-down", structure support/underpinning, alternative face stability measures, composite systems, hollow bar and fiberglass nails and architectural reinforced concrete/shotcrete facings. Case histories will be presented to illustrate each of these advances.

Jan 1, 2003

By F. W. Jessen, C. C. Patton

Adsorbed films were formed on polished stainless steel specimens from dilute benzene solutions of two crude oil distillation residua. Although the two residua were extremely dissimilar in composition, contact angle measurements showed that the two films increased the wettability of the steel specimens to oil by equal amounts. Furthermore, the wettability of the films was essentially unaffected by the desorption techniques used. Paraffin deposits were formed from heptane-wax solutions on the same stainless steel specimens. These deposits definitely adhered to the surface. Presence of an adsorbed crude oil film on the metal surface increased its free surface energy and resulted in increased deposition of paraffin. The addition to the heptane - wax solution of small amounts of the same distillation residua that were used to form the adsorbed films resulted in decreased cohesive strength in the deposits formed, which resulted in decreased deposition. The presence of a crude oil fraction both in the solution and as a preadsorbed film eliminated the adherence of a deposit of any kind. A mechanism of deposition is proposed which explains the results obtained. INTRODUCTION The natural formation of any predominantly organic accumulation in oilwell tubing, surface flow lines or other production and storage facilities is called a paraffin deposit. These deposits restrict the production of crude oil, causing a substantial increase in production costs because of decreased flow capacity, expense for periodic deposit removal and unproductive downtime. The conditions under which such deposits form, their physical characteristics and the nature and severity of the problem created are extremely varied. Over the past several years, much progress has been made in developing and utilizing methods to remove accumulated paraffin deposition. However, like so many other problems, the basic stumbling block appears to be a lack of understanding of the fundamental mechanism involved in the formation of such deposits. Crude petroleum is known to contain considerable quantities of polar, surface active substances which Doddl has shown to be present at the oil-water interface. Denekas, Mattax and Davis2 observed that the wettability of reservoir rocks was drastically altered by exposure to crude oil fractions; and Zisman, et a1.3 showed that the nature of the compounds adsorbed on a surface would determine its wettability characteristics. Cole and Jessen4 and Ehrig5showed that surface wettability can have a profound effect on the magnitude of paraffin deposition, and Parks6 demonstrated chat the presence of certain adsorbed films on a metal surface would reduce the adherence of paraffin to that surface. Zisman7 has since advanced the theory that the conditions for adhesion are the same as for wetting. Therefore, it was felt that there was adequate evidence to support the supposition that adsorption of compounds from a crude oil might play an important part in paraffin deposition. ADSORPTION-WETTABILITY EXPERIMENTS Initial experiments were conducted to determine the effects of adsorption from solution of crude oil residua on the wettability of a polished stainless steel surface. Distillation residua with initial atmospheric boiling points of 700F were used in preference to the whole crudes in order to concentrate on the molecular weight range of interest, and to eliminate the possibility of composition change due to evaporation of the light ends. Also, these high boiling materials would be expected to be adsorbed from the whole oil in preference to similar compounds of lower molecular weight.

Jan 1, 1966

By C M. Wawryk, S L. Garwin, J D. Foden

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Batu Hijau porphyry Cu-Au deposit in south-western Sumbawa, Indonesia is an ideal natural laboratory to study the fractionation of iron isotopes in magmatic rocks that range in composition from basaltic andesite to tonalite. Intrusive rocks are associated with a porphyry system that contains well-preserved early hypogene copper mineralisation. We analysed pre-, syn- and post-mineralisation igneous intrusive rocks. We also separated magnetite, chalcopyrite and bornite from hypogene porphyry-style quartz veins, and measured the Fe-isotope ratios of samples by solution multi-collector ICP-MS. Iron isotopic composition of samples from the magmatic suite show an increasing d57Fe with increasing SiO2, supporting geochemical and textural evidence that the Batu Hijau Tonalites underwent closed system fractionation. Equilibrium and co-existing mineral textures allow the calculation of the following preliminary empirical mineral-mineral fractionation factors at 500°C for certain mineral pairs.Iron isotopes have the potential to provide geothermometric data to complement fluid inclusion data, especially where heating stages have operational limitations and where fluid boiling results in a wide variety of inclusion types that may make analysis difficult.CITATION:Wawryk, C M, Foden, J D and Garwin, S L, 2015. Iron isotope fractionation in magmatic-hydrothermal minerals – a porphyry copper case study from the Batu Hijau deposit, Sumbawa, Indonesia, in Proceedings PACRIM 2015 Congress, pp 389–396 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By T. O. Hagan

Analyses of accident records show that a better understanding of very basic strata control principles and practices, by production personnel, will improve worker safety. Workers, lack of knowledge, with respect to aspects of strata control, increases their exposure to such strata control risks. The primary objective of the Safety in Mines Research Advisory Committee (SIMRAC) project 02 02 07 was to develop tools for the transfer of strata control knowledge. Four such tools were developed, three of which focused on illiterate underground mine team members who are not yet able to take advantage of the Mining Qualifications Authority (MQA) learning process (see project outcomes 2, 3 and 4 below). The tools were designed to equip these workers with sufficient knowledge and ability to work safely underground until such time as they can take advantage of the MQA system. Project outcomes: 1 A four-minute video using animation to illustrate the causes and prevention of falls of roof in South African collieries. 2 Software to demonstrate the capability of reconstructing, interactively, accident scenes and actions that have taken place underground in stopes. 3 A strata control bridging course for illiterate mine team workers. 4 Small-scale wooden models that will be used to design life-size mock-up facilities to assist with the above mentioned bridging course. 5 Workshops and presentations to demonstrate the outcomes 1to 4 above.

Jan 1, 2005

By D N. B Skinner, M P. Simpson

At Ohio Creek, 3 km northwest of the Thames bonanza goldfield, porphyry Cu-Au mineralisation is hosted in a dacite porphyry associated with porphyry intrusion breccias and overlying andesites and dacites. The geological setting is a Jurassic greywacke basement overlain by Late Miocene andesite-dacite volcanics which are extensively altered to propylitic and argillic assemblages. Diamond drilling at Ohio Creek in 1978-1981 by Amoco Minerals intersected low grade Cu-Au (0.12-0.20% C~ 0.23-0.4 glt Au) mineralisation An advanced argillic 'alteration cap containing quartz-alunite¦dickite or pyrophyllite-dickite¦diaspore is centred on the adjacent Lookout Rocks and has potential for high sulfidation Au-Cu mineralisation. There is a zonation from potassic K-feldspar-magnetitealteration at depth in the dacite porphyry, through an overlying phyllic quartzsericite- pyrite zone which is overprinted by pyrophyllite in the overlying advanced argillic cap. Early quartz stockwork veinlets associated with the potassic alteration contain fluid inclusions that trapped a highly saline (50-80 wt% NaCI equiv) fluid at high temperatures (450 to >600¦C) indicative of a magmatic fluid. Some chalcopyrite is associated with slightly later quartz-magnetite veinlets, but the bulk of the copper occurs as disseminated chalcopyrite associated with the phyllic alteration. The potassic alteration is surrounded and overprinted by propylitic chlorite¦epidote alteration. Late polymetallic sulfide-quartz-anhydrite veins occur within and around the margins of the porphyry system as in the Kaiser Reef. Fluid inclusions associated with these late veins were formed at temperatures of about 250-320¦C from low salinity (1-3 wfl~ NaCI equiv) fluids. The spatial association between porphyry eu-Au mineralisation, advanced argillic alteration and polymetallic sulfide veins suggests that they are genetically part of the same hydrothennal system. This is consistent with reconnaissanceK-Ar dates of 11.6-10.7 Ma for the intrusive porphyry at Ohio Creek, alunite in the advanced argillic alteration zone at Lookout Rocks and sericite selvedges from the Waiotahi gold-quartz veins at Thames.

Jan 1, 1998

By Peter B. Dowden, Robert A. Robinson

Boulders, frequently found in tunnels excavated through soils, can pose major problems for full face TBMs in terms of slowing or halting the tunnel advance, cutter damage, and abrasive wear. The paper aims to consider the problem as a whole, from the geological characteristics of boulder sites, to the appropriate physical design of theTBM, and its operation in boulder-laden soils. In addition, visualization of boulders and other subsurface obstructions by seismic methods and ground penetrating radar are reviewed. The paper will assist the construction planner in assessing the risks and preparing appropriate specifications.

Jan 1, 2001

By Y. Nien Wang, Moe Amini, Heiner Sander, Max John

INTRODUCTION As the population increased along the coast route (California Route 1), and the people’s need to have guaranteed access increased, the landslides and related road closures began to have serious adverse economic impacts. Landslides were causing major long-term road closures about every 10 years on average. In 1983, ground movement at Devil’s Slide caused Highway 1 to be closed for an extended period of time which caused significant economic loss to the surrounding coastal communities. A number of options for bypassing the slide area were considered, and the Martini Creek inland bypass was selected for design. Subsequent litigation led to the creation of the Devil’s Slide Tunnel Study in 1996. The results of this study indicated that a tunnel alternative would be competitive with the inland bypass. The final decision was left to the citizens of San Mateo County, who approved the tunnel alternative in the November, 1996 election After completion of environmental studies and the processing of legal challenges, the final environmental document was finished in 2001. The preferred tunnel alternative was designated to proceed for final design and construction. PROJECT DESCRIPTION The Devil’s Slide Tunnels consists of a separated two-lane road, one lane in each direction, which passes through twin tunnels and over twin bridges and then connects with the existing non-separated, two-lane road at each end. The total length of the project is approximately 1900 meters consisting of four main project divisions, which are described below, going from south to north. 1.Operations and Maintenance Center (OMC) area, 2.Southern approach roadways to the South Portals (250 meters), including the South Rock Cut,

Jan 1, 2005

By M. Sharafodin, A. A. Hassanipak

Abstract - The essential aims of additional borehole drilling are to improve the reliability of grade and tonnage estimates in each reserve class and to increase ore tonnages. The "GET" function presented in this paper considers strategies for achieving both of these goals simultaneously, and therefore is advantageous for selecting sites for additional boreholes. The "GET" function is either a linear or a non-linear product of three variables G, E, and T: f(G,E,T,) = G??E??T??where the values of any or all of the exponents ?, ?, and ??may differ from unity at the discretion of the user. G and E are the average estimated block grade and the average estimation error for ore blocks in one vertical column, and T is the compounded ore thickness within the column. To illustrate its utility, the GET function has been used for determination of the most advantageous sites for additional drilling in the Shah-Kuh Pb-Zn deposit in west central Iran.

Jan 1, 2004

By T. Ogasawara, J. P. Barbosa, A. J. Monhemius, F. T. Da Silvia

A thermodynamic analysis of the sulphation of rare-earth phosphates and the water-leaching of rare-earth sulphates was used to guide experimental work on the sulphation and leaching of concentrates from Pitinga. It was concluded that the sulphuric acid digestion of xenotime is technically feasible and could be used industrially to produce yttrium and other rare-earth oxides. Yttrium extractions of more than 90% were obtained by digestion at 503 K for 4 h at an acid:concentrate ratio of 2:1 with particle size -0.053 mm. The apparent activation energy at temperatures less than 473 K, as determined from the Arrhenius plot, was 11.0 kJ/mol, indicating that the reaction is controlled by the diffusion of the reactants or products through the sulphate layer

Jun 19, 1905

By K. Leutwyler, H. L. Bigelow

Jan 1, 1966

By B. R. Reddy, Y. V. Swamy, B. V. R. Murthy, H. S. Ray

The Ni oxide was reduced with a CO-CO2-N2 gas mixture and the effects were observed of process variables such as roasting temperature, time and CO partial pressure. Extraction of over 90% of Ni was achieved by ammoniacal leaching of ore that had been reduced for 1 h at 760 degrees C under a gas mixture with a volumetric CO/(CO+CO2) ratio of 0.57. The kinetic data were found to conform to the Ginstling-Brounstein equation. The applicability of this model was confirmed by evaluating the apparent activation energy with the use of independently constructed differential and integral plots, which showed an excellent match

Dec 1, 1995

By Mingyang Li, Yan Lv, Xiaolong Ma, Xudong Gao, Jie Zhao, Yingyi Zhang

The reduction process of pre-oxidized ilmenite concentrate powder in 30%CO–70%N2 atmosphere was characterized by thermogravimetric and differential thermogravimetric (TG-DTG) analysis system at the temperature from 1073 to1223 K. The isothermal reduction results show that the reduction process is divided into three stages and the corresponding apparent activation energies are obtained by iso-conversional method and model-fitting method, respectively. For the first stage, the conversion degree increases sharply with increasing time, and the reduction process is controlled by the random nucleation and subsequent growth model (A2 model). For the second stage, the conversion degree increases slowly with increasing time, and the reduction process is controlled by the diffusion of carbon monoxide in the reduced layer (D1 model). For the third stage, the reduction processes at different temperatures are controlled by the diffusion of carbon monoxide in the reduced layer (1073 K and D1 model), phase boundary chemical reaction (1123 K and R2 model), random nucleation and subsequent growth (1173 to 1223 K, A2, and A3 models), respectively. For the whole reduction process, the apparent activation energies obtained by iso-conversional method and model-fitting method are 71.72 and 31.92 kJ mol−1 , respectively

By R. A. Gee, G. B. Ashton, S. T. Warren, P. N. Groves

Northside Storage Tunnel provides 500 megalitres (Ml) (130 million gallons) of storage capacity to capture stormwater/sewage overflows into Sydney Harbour. The6.6 m diameter TBM driven tunnel traverses Middle Harbour 85 m (280 ft) below sea level and through a sandstone/shale rock mass, highly disturbed by stress relief, 20 m(65 ft) beneath the base of the sediment filled palaeochannel. Target limits for inflow, groundwater drawdown and settlement of the valley beaches were achieved by systematic forward grouting from the TBM. Support included rockbolts, sets and shotcrete to carry rock loads, control block instability and spalling and to provide durability and serviceability. This paper describes the tunnelling and grouting works and their effectiveness.

Jan 1, 2001

By S. N. Lekakh

Phosphorous segregated at grain boundaries during solidification and heat treatment dramatically decreases low temperature toughness of precipitation hardened Fe-Mn-Al-C austenitic steel. A thermodynamic analysis was performed to evaluate the possibility of decreasing P and subsequent segregation by Ca- and Ce-additives in the melt. It was shown that the predicted probability of forming a P containing compounds depends on melt composition and treatment sequence. Experimental heats were performed and several micro- and macro-structural effects of Ca- and Ce-additives were recognized by using an automated inclusion analysis technique.

Jan 1, 2010

By L. B. Davidson

The petroleum literature contains many reports on the relative permeability properties of porous media. However, only recently have studies of relative permeability at elevated temperatures been made.1 -5 Each of these studies presents relative permeability data on water-oil systems in linear sandpacks or sandstone cores under isothermal conditions. The results of these investigations are dissimilar. Edmondsonl found that in Berea sandstone a temperature-dependent effect was present, while Shilobod,2 using the same material, found no temperature dependence after normalizing for initial water saturation. Workers at Texas A&M U.3-5 found that the ratio kw/ko was temperature dependent in an unconsolidated system. The differences in results of these studies are probably a consequence of differences in the material employed, in the experimental procedures followed, and in the properties of the porous systems used. This paper describes an experimental investigation of permeability ratio temperature dependence, conducted to clarify some of the results obtained by previous workers. Each experiment described in this paper involved the isothermal displacement of Chevron No. 15 white oil by either nitrogen, steam, or distilled water and displacement of water by nitrogen. All permeability ratios were calculated using the Welge procedure. Values of the water-oil permeability ratio were obtained over the temperature range 75OF to 540°F. Results indicate the ratio is temperature dependent at low water saturations, probably due to interfacial effects. However, as the saturation is increased, temperature dependence decreases until, above some minimum saturation, the ratio becomes insensitive to temperature. Previously published work indicates that the dependence reappears at very high water saturations, a region of the ratio curve not completely examined in the present study. It appears that water-oil permeability ratios are temperature dependent at the extremes of the ratio curve where changes in interfacial tension with temperature induce variations in residual saturations. Between the extremes, there is a region in which the permeability ratio is insensitive to temperature. The size and location of this region is probably a function of the characteristics of the porous system. Gas-oil permeability ratios calculated from nitrogen-white oil displacement experiments indicate a definite temperature dependence over the range 75OF to 500°F and over the entire gas saturation range studied. Evidence discussed in this report indicates that this dependence is a consequence of molecular slippage in the gas phase. This is an extension of the Klinkenberg effect6 to two-phase systems at high temperatures (the existence of slippage in two-phase systems at room temperature has been demonstrated7). Evidence for a similar source of temperature dependence in superheated steam-white oil experiments

Jan 1, 1970

By A. M. Gaudin

Jan 1, 1962

By Hamid Maleki

A geotechnical monitoring program has been implemented at Energy West Mining Company for enhancing site-specific evaluation of longwall stress conditions. This program consists of underground measurements at five locations in two neighboring mining districts located in the Hiawatha and Blind Canyon Coal Seams under moderate to deep cover. Within the last five years, additional measurements, including data on recorded seismic events and face conditions, have been incorporated into the data collection program together with detailed geologic mapping of longwall gateroads. In conjunction with the measurement program, the authors have completed detailed boundary-element stress analyses of the mine plans. Models have been calibrated using the data from in-mine instrumentations and then routinely used for evaluation of mine plans at depths approaching 2,600-ft. The work has improved our understanding of load transfer, seismicity and yield pillar performance. It has identified areas of potential increased stress levels at certain longwall face positions and provided guidance to measures that could be considered to mitigate the potential for these increased stress levels.

Jan 1, 2009

Flat jack stress determinations in selected colliery roadways have revealed a range of measured stress from 330 lb/sq. in. tension to 3,750 lb/sq. in. compression. Photoelastic examination of loaded plastic and actual rock model mine openings has shown that the primary horizontal stress required to attain these measured stresses would be from one to three times the superincumbent vertical load.Examination of roof movement with a borehole extensometer and a series of anchors at various horizons to 30 feet in a vertical roof borehole showed that when a standing face was advanced the roof movement was practically confined to the lower two feet. The majority of this movement occurred during the 36 hours after mining at this face commenced.The use of a radioactive isotope and a scintillation counter in a pair of parallel boreholes is a sensitive and accurate method of roof bedding plane crack detection.INTRODUCTIONA knowledge of strata stresses is required to understand the deformation of an underground opening and, in particular, the roof behaviour. It is the aim of investigations currently being conducted by Australian Coal Association (Research) Ltd. to determine the stress existing around mine openings and the location and magnitude of roof movement.STRATA PRESSURE MEASUREMENTMost measurements of strata stress are performed at the surface of underground openings and the majority measure the change of strain resulting from stress relief. The accuracy of the measured value of stress depends upon knowledge of the rock modulus of elasticity. The flat jack method has the advantage that strain relief is restored by a measured stress applied directly by the jack. The rock modulus of elasticity can also be determined.

Jan 1, 1963

By H. A. Bilgin, G. G. U. Aldas

"Ground vibration is the natural result of the blasting process. Many empirical formulae and methodologies including analysis of travel path effects have been developed. The scaled distance, which is the most popular approach for the calculation of the attenuation of particle velocity in the ground, has led to significant advances in the prediction of particle velocity when both explosive charge and distance vary. However, this approach does not consider the effect of ground anisotropy and existence of structural geological features on ground vibration. Therefore, in this study, the effects of these rock mass properties on types, amplitudes, and frequencies of ground vibration waves at four surface mines are examined. The results, which were implemented at Kangal coal mine, Bastas quarry and Kíbrís quarry, provided guidance for the extensive study at Orhaneli surface coal mine.As a result of the study, the authors came to the conclusion that vibration amplitudes change depending on the ground on which sensors were deployed and the conditions depending on whether measurements were done near major structural geological features. It was determined that the vibration amplitudes, measured at equal distances from the source but in different directions, change because of the propagation velocity anisotropy. Besides the change of wave type due to the kind of ground at the measurement location, it was determined that vibration anomolies were due to structural features."

Jan 1, 2004

By SungJe Chi

Intrinsic remediation is the effect of natural attenuation mechanisms - dilution, dispersion, sorption/precipitation and biodegradation - reducing contaminant concentrations in ground water to specified levels at predetermined compliance points in the aquifer. Current monitoring and modeling for post closure was used to assess the current and long-term potential of intrinsic remediation of contaminated seepage originating from a large reactive (sulfidic) tailings impoundment near Questa, New Mexico. It is concluded that the natural attenuation mechanisms of precipitation within the tailings (as a result of buffering) and dilution/dispersion within the aquifer are currently active and likely sufficient to reduce contaminant concentrations to below state standards in the long-term. Other natural attenuation mechanisms such as sorption and biodegradation within the receiving aquife4s) were not assessed here, but are likely further reducing contaminant concentrations. Active interception and recovery of the seepage water is being maintained until monitoring demonstrates that intrinsic remediation has successfully achieved the level of water quality control required.

Jan 1, 2017