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By Todd Kilduff, James Grillo, Shrey Arora

In efforts to improve ingress/egress from the existing subway platforms in PATH’s Exchange Place Station, a new 18-foot horseshoe cross-passage tunnel was constructed by Walsh Construction who retained Kilduff Underground Engineering for design of the initial support system and to install and maintain geotechnical instrumentation. The project presented some unique challenges as a result of the proximity to pedestrians on the platform. PATH service remained uninterrupted, limiting the Contractor to mechanical means of excavation to advance the heading. The logistics proved very challenging for the approximate 100-foot-long tunnel excavated in soft Manhattan Schist. This paper will present the design and construction challenges for the project.

Dec 1, 2022

By Saverio Agresti, Giuseppe Lunardi, Donato Basta, Roberto Trapasso

"At a distance of 10 years from the first application of the Nazzano Method, the widening under traffic of a tube of an existing motorway tunnel was realized near Ancona, along the A14 Motorway in Italy. This paper describes the works for the enlargement with conventional method of the second tube, very close to that already widened under traffic.This enlargement was realized very fast, taking into account the advantages of some interesting technological improvements of the Final Design proved in the first tube.INTRODUCTION TO THE WIDENING OF EXISTING MOTORWAY TUNNELSThe widening of a twin-bore motorway tunnel usually considers the double option of creating a third bore as an alternative or closure to traffic of one of the two bores with the resulting reduction in the level of service for users.On the contrary, the extension in situ of a road, motorway, railway or underground tunnel in the presence of traffic, made possible by an inspired idea of Prof. Pietro Lunardi, enables the level of service of the infrastructure to be maintained without the need to resort to alternative routes to create new permanent or temporary bores, not always feasible because of the lack of the necessary space.This construction technique, known as the ‘Nazzano Method’, is part of the technologies refined and offered by the ADECO-RS approach to tunnel design and construction (Lunardi P., 2008) which is increasingly used in the world, leading to the industrialisation of tunnelling (meaning respect for the times and costs set out during detailed design) both in conventional and mechanised (through TBM) excavations.The first true experimentation of the ‘Nazzano Method’ was carried out between 2004 and 2007 to enlarge the two-bore ‘Nazzano’ tunnel (Italy, Milan-Rome A1 motorway) in the presence of traffic, widening it to house from two to four lanes in each direction (Lunardi P. et al., 2007). Following the success achieved in this first application, the Nazzano Method was strengthened considering all the possible suggestions arising from the previous experience and then taken up to enlarge the north bore of the ‘Montedomini’ two-bore tunnel (Italy, Bologna-Taranto A14 motorway), in situ and the presence of traffic."

Jan 1, 2016

By D. Meadows, P. Carrato, E. Wingate, K. Churchill

Extracting lunar ice, to be processed into pure water or hydrolyzed into oxygen and hydrogen, faces many challenges. On the Moon icy-regolith deposits that contain up to 10% water are found within Permanently Shadowed Regions (PSR) at both lunar poles, where temperatures approach -220 ⁰C. NASA has identified several technology gaps that exist in developing these resources including: • Excavating large quantities of icy-regolith • Delivering large quantities of acquired resources • Hardware that is lightweight and energy efficient • Hardware that is reliable and durable. NASA uses public challenges to incentivize innovative approaches to closing these gaps. The Break the Ice Lunar Challenge provides over three million dollars in prize money to teams that compete in developing solution to mining the Moon. This paper describes the rules for this challenge and presents some of the proposed solution.

Feb 1, 2023

By Gy. Deák Deák

The ECOMINING platform aims to develop a scientific and technical organization in order to promote within the natural resources industry a framework for environment-friendly exploitation technologies (on Best Available Technologies principle) and also to develop a solid basis for performing Research and Development projects. The ground of this project is the success of the First International Seminar: ECOMIN-ING - Europe in 21st Century1, organized by the Research and Development National Institute for Metals and Radioactive Resources Bucharest in co-operation with ITASCA Consultants GmbH Germany, the University of Petrosani and supported by the National Society of Salt Bucharest & Praid salt mine branch and the Ministry of Economy and Commerce. The platform provides a complex data base, for partners? selection and researchers? team structure. This can provide the scientific results with a high level of confidence for the projects of interest in the field of exploitation of mineral resources and for the participation on national and international project proposals competitions (i.e., target the 7th Framework Programme or any European / national programme, which can provide funds for the ECOMINING platform field of interest). The next step is the affiliation of the ECOMINING platform to the European ones, and to be compatible with them. The ECOMINING platform represents itself a 7th Framework Programme (FP) project idea.

Jan 1, 2007

By William P. Blacutt

This paper describes the strategy, the struggles, and the obstacles encountered during the last two years in the ongoing process to capitalize Vinto. The effort involves the offering of a vertically integrated business package composed of the tin and antimony smelters along with the two principal tin mines of the country. Capitalization: Bolivia's Innovative Approach for Privatization, the Vinto Case provides a summary of hard-earned lessons. These experiences can be success- fully implemented in other nations committed to transforming their state natural resource sector.

Jan 1, 1998

By Libby R. Ricafort, Nonato S. Retardo, Jose B. Anievas

This paper shows the metallurgical test results that led to the design of the heap leach facilities of Philex Mining Corporation. The design incorporates a water management model as process solution circulation is excessive with high rainfall intensity in the area. This poses problems in the operations requiring stringent controls than would be necessary in a less severe environment. The corporate perspective embraces on environmentally-sound mineral development. A budget is always provided to environmental management making certain that no industrial development is moved forward at the expense of the environment.

Jan 1, 1996

By John J. Simmons

There is considerable interest in the iron and steel industry in the development of technologies that can reduce carbon dioxide emissions, as the iron and steel industry is the third largest producer of carbon emissions in the world, after automobiles and the power generation industry. The E-Iron Iron Nugget Making Process, invented by Dr. Komar Kawatra and Dr. Tim Eisele, provided a major breakthrough in the iron making process as the process uses biomass in the form of hard wood or soft wood as the reductant in the place of coal. Dr. Kawatra recognized that biomass is rich in both carbon monoxide and hydrogen, two important reducing agents. This resulted in initial experiments conducted by Dr. Kawatra and Dr. Eisele in the laboratories of the Chemical Engineering Department of Michigan Technological University (Michigan Tech) that prepared self-reducing pellets with wheat flour as the reductant and limestone/dolomite as the flux. Initial results were encouraging so they extended their work to include hardwood, which is in huge supply in the forests of Michigan and Minnesota, as the reductant. Dr. Kawatra has also applied the E-Iron Technology to other iron bearing minerals to produce pig iron grade iron nuggets. He used the E-Iron Process to convert red mud, a high iron waste product of the aluminum industry, into pig iron nuggets with the rare earth elements reporting to the slag. This work resulted in a patent with Dr. Kawatra and Dr. Michael Archambeau named as the inventors. Dr. Kawatra then extracted the rare earth elements as a separate high value bi-product using oxalic acid, which he produced from carbon dioxide. Dr. Kawatra also conducted a test program that produced pig iron nuggets from New Zealand beach sands. The vanadium in the beach sands was retained in the iron nuggets, recoverable as a valuable bi- product in a separate process. The titanium dioxide in the beach sands reported to the slag. This demonstrates the potential use of the E-Iron Process to convert the large ilmenite reserves in Northern Minnesota into pig iron and titanium dioxide. Another use of the E-Iron Process discovered by Dr. Kawatra was its ability to produce iron nuggets from manganiferous ores. Dr. Kawatra was able to direct the manganese into either the metal or slag by adjusting process temperature. The above discoveries are included in several patents that were assigned to Carbontec Energy. This presentation will only address the use of the E-Iron Process to produce pig iron nuggets from steel mill waste and un-pelletized, mid-grade iron ore. Carbontec Energy Corporation agreed to sponsor additional research directed at improving this new technology that would later be trade named, The E-Iron Process. Carbontec Energy conducted further work that proved that the E-Iron technology could also convert steel mill waste into metallurgically acceptable iron nuggets. Carbontec also collaborated with the Lawrence Livermore National Laboratory and Purdue University Northwest to conduct a Department of Energy (DOE) sponsored program that would use their high performance computer capability to both verify and model the E-Iron Process. Purdue University Northwest reported that the E-Iron Process can produce pig iron nuggets with 85% less carbon emissions than a blast furnace. The E-Iron Process is similar to the ITmK3 process, developed by Kobe Steel, that also produces iron nuggets but uses coal as the reductant.

Feb 1, 2025

By B. Listerud, G. Zhan, M. A. Jones

Barrick Goldstrike Mines Inc. (BGMI) operates the Betze-Post openpit and the Meikle and Rodeo underground mines. Because the majority of the orebody is located below the water table, mining at BGMI requires a significant dewatering program. BGMI has a comprehensive dewatering and water management system that experienced a peak dewatering rate of 4,400 L/s in the mid 1990s. Changes to the hydrologic/hydrogeologic system caused by the mine dewatering have been monitored by an extensive network of groundwater monitoring wells and surface water monitoring stations, which cover about 1,550 km2. In addition to the monitoring program, a new tool, called Interferometric Synthetic Aperture Radar (InSAR), has also been used to enhance the evaluation of changes. Finally, a groundwater flow model has been developed that successfully simulates and predicts aquifer responses in the mine area and region. The well-calibrated flow model has served as a reliable tool to develop dewatering and mining plans, and project post-closure hydrologic conditions in the region. This paper introduces the BGMI dewatering and water management system and the means used by BGMI to evaluate and anticipate hydrologic responses in the region. The water management and analysis system has been and continues to be an integral part of managing ongoing operations, planning and pricing out future activities and evaluating the long-term effects of mine water handling.

Jan 1, 2011

By A. Jennings, J. Cornet, P. Perrone

Controlling long overland conveyors with multiple drive stations is a complex problem. The methods for controlling these belts in a steady state are well-covered in existing literature, but a discussion of starting and stopping strategies is absent. This paper outlines different control strategies for starting, stopping and running conveyors with multiple drive stations. To illustrate the benefits of applying the methods described in this paper, the authors show how their adoption corrected many of the control system problems at Essroc Cement’s overland conveyor, which features three drive stations separated from each other by long lengths of continuous conveyor belt.

Jan 1, 2013

By Bernard P, Lhoumaud E, Gunzburger Y, Conin M, De Santis F, Kinscher J

Seismic repeaters are commonly observed in natural fault zones dominated by slow aseismic motion. The corresponding seismic signal, characterized by highly similar wave forms, is usually interpreted as the repeating ruptures of locked asperities on fault planes (“patches of higher roughness”), loaded by a-seismically slipping areas (“creeping areas”) (Chen & Lapusta 2009; Bourouis & Bernard 2007). Only very few occurrences of seismic repeaters have been reported in underground mines, where these phenomena are rather unexpected since the stress state and the seismic wave propagation continuously evolve with the advancing excavation front (Kinscher et al., 2020). A recent study based on a local seismic network installed in the underground mine of Garpenberg, Sweden, has shown that seismic repeaters and multiplets represent the main part of the total released seismic energy (magnitude of seismic events: -2 < M <1, on moment magnitude scale), with some seismic families being active during several months to years. It is suggested that repeaters are linked to aseismic slip on pre-existing talc-filled fractures, induced by the excavation, and loading of asperities. These results imply that part of redistribution of stresses in the mine is due to aseismic slip, which might explain the observed distant and delayed seismicity.

Apr 26, 2022

By A. Yehia

Fluoride activation has been evaluated by Hallimond-tube flotation of collophanite in terms of fluoride concentration, conditioning time, pH, and temperature. The results reveal that efficient oleate flotation of collophanite can be achieved by fluoride activation. Fluoride adsorption by collophanite as a function of fluoride concentration, temperature, pH, and crystal structure suggests that, at low fluoride concentration, a fluoroapatite-type compound may form on the collophanite surface by chemisorption of fluoride ions at calcium sites; at high fluoride concentration, calcium fluoride ap¬pears to form at the collophanite surface invovling a surface-precipitation phenomenon. The formation of CaF2 on the surface of fluoride-treated collophanite is further substantiated by the FTIR spectroscopic measurements, which clearly shows a metathetic exchange with phosphate from the collophanite lattice during surface precipitation process.

Jan 1, 1986

By MARK J. VANARELLI

Estimating groundwater inflows in rock deep tunnels is critical to the safety of personnel constructing the tunnel and the cost of construction. This paper presents two case studies for estimating steady-state groundwater inflows into deep rock tunnels. The case studies included the Chattahoochee and Nancy Creek tunnels. In this paper, statistical methods were applied to packer test data obtained from exploratory borings during geotechnical site investigations. A semi-empirical procedure was utilized for estimating groundwater inflows into these deep rock tunnels. The Chattahoochee and Nancy Creek tunnels are deep rock tunnels which exhibit radial flow conditions. For the radial flow condition, a statistical analysis presented in this paper indicates that the semi-empirical procedure works well; however, variations in the procedure and/or an insufficient amount of testing could lead to underestimations of the inflow quantities. Packer test data plotted in histograms were observed in all cases to be log-normally distributed for the radial flow condition. Modeling using Monte Carlo simulations was observed to be an effective tool for removing irregularities in the distribution of the data and incorporating high-end permeability data to derive reasonable groundwater inflow estimates.

Jun 13, 2021

By B. Ladanyi

An adequate knowledge of the overall behavior of a rock mass at a given site is fundamental to the satisfactory design of a rock slope. The be- havior is controlled by a variety of factors, in- cluding rock type, geological structure, stress and ground water conditions. There are essentially three lines of approach that may be used to obtain information on the in-situ rock mass behavior for the purpose of the design of a rock slope: (1) Direct measurements of rock mass properties by means ol laboratory and field tests. (2) Evaluation of rock mass properties from a study of slope failure case histories and sta- tistical information on stable and unstable natural rock slopes. (3) Evaluation of in-situ behavior of rock mass by using a physical or mathematical model technique.

Jan 1, 1980

By Rakesh Sehgal, Pushkar Verma, Mohit Sharma

"SJVN Limited successfully commissioned its Rampur HEP (412 MW) in 2014. The project has been planned to operate in tandem by directly utilizing the Tail Water of SJVN’s prestigious Nathpa Jhakri Hydro Power Station 1500 MW located upstream. The initial filling of voluminous water conductor system of RHEP with 10.50 m diameter, 15 Kilometer long Head Race Tunnel, involved more than 1.5 million m3 of water. The filling operation of such a large diameter tunnel constructed in young folded Himalayas which always offer less ideal sites for tunnelling and their subsequent operations under pressurized conditions is worth sharing with tunnelling fraternity. The paper covers meticulous planning, execution, precautions taken, and performance monitoring during filling process keeping in view the fragile geology, low rock cover zones, shear zones in close vicinity of thickly inhabited areas, squeezing zones, hot water zones encountered during excavation.1.0 RAMPUR HYDRO POWER STATION IN BRIEFRampur Hydroelectric Project (412 MW), is located in Himachal Pradesh (India). This project is a downstream development of Nathpa Jhakri Hydro Power Station (1500 MW) constructed on river Satluj and commissioned during 2003. Both the projects today are now successfully working in tandem. The upstream NJHPS has been constructed on the left bank of the river while the downstream Rampur HPS is located on right bank of the river (Figure-1).The major length of HRT of Rampur project lies on right bank of river before it crosses under the river in its initial reach (Figure-2). The main features of the project are as below:• 10.50 m diameter 15 km long HRT ending in a 155.75 m deep, 38.00 m diameter surge shaft.• 3 steel lined pressure shafts, 5.4 m dia, 211-220m long.• Surface valve house 69 m long x 10.50 m wide x 23 m high housing 3 No. butterfly valves• 3 No. surface penstocks 5.4m dia 368-382m long, bifurcating into six penstocks, each of 3.80 mdia. to feed six generating units of surface power house 158 m long x 24.50 m wide x 48 m high, with Francis turbines each of 68.67 MW capacity."

Jan 1, 2016

By Don Reining

The sand and gravel industry in Southern California has made a sizeable contribution to the construction development of the 15 County area in this part of the State. Facing this mineral extraction industry, in the next decade, is a problem of meeting the market demand. The question is, "how can sand, gravel and rock operations be made compatible with goals for sound and attractive community development?" Three basic principal characteristics of the land needed for this-mining industry are: 1. The land must have workable sand, gravel or stone deposits. 2. The land must be properly located for transportation purposes close to the market in order to sell the aggregate at a minimum cost. 3. The land must be zoned so that it will be permissible to mine.

Jan 1, 1967

By Karl Gunnar Holter, Frank Clement

"INTRODUCTION Typically waterproofing of conventionally excavated tunnels has been done by installing pre-fabricated sheet membranes between the primary temporary support lining and the secondary permanent inner lining. The membrane acts as a separation or sliding layer between the linings, which is often desirable. The geotextile installed behind the sheet membrane provides the required drainage and protection of the system. The design of the tunnel lining is strongly influenced and limited by the use of waterproofing sheet membranes. Since primary and secondary linings are separated from each other, forming a double-shell lining system. In that case the secondary lining must be designed for all permanent loads, although the sprayed concrete primary lining continues resists ground and water loads for a long time after construction. Significant progress has been made in sprayed concrete technology over the last two decades, with advanced admixtures, as well as the improved application technology using spraying robots. The development of new admixtures like superplasticizers based on poly-carboxylates, alkali free accelerators and silica fume, enables designers to use permanent sprayed concrete linings (SCL) increasingly for long-term service life. When designed and applied correctly, sprayed concrete can be considered as permanent. The use of spray applied membranes has seen increased use over the last decade in some countries, and demonstrated functionality and cost-effectiveness in several situations. This paper describes the use of the sprayed waterproofing membrane MasterSeal 345, an EVA polymer based product, and the practical experiences from several projects. SPRAY APPLIED WATERPROOFING MEMBRANES The sprayed waterproofing membrane is polymer based and has been especially developed for underground structures. The membrane is applied between primary and secondary concrete linings and develops high bond strength on both sides to the concrete (doubled-bonded)."

Jan 1, 2016

By William W. Edgerton

Establishing geotechnical baselines on soft ground projects that require the use of closed-face tunnel boring machines (TBMs) is difficult. It is hard to see the face when mining and the excavated material is combined and mixed, all of which makes baseline quantifications challenging. In an attempt to meet underlying objectives of minimizing bidder contingencies, allocating or sharing risks and paying for conditions only if they occur, nongeotechnical baselines (i.e., functional baselines) have been developed. These have been used on the District of Columbia Water and Sewer Authority?s Clean Rivers (DCCR) Blue Plains Tunnel (BPT) project. This article examines the development of such functional baselines and how they were implemented on the BPT project.

Jan 1, 2012

By Y. Luo

Based on the concept of slope stability analysis, a formula for determining an important parameter required in the mathematical model for the prediction of mining subsidence in hilly terrain has been proposed. The slope geometry and soil physical and mechanical properties of the surface natural slope can all be considered in the formula. Incorporation of this new formula into an existing mathematical model provides an integrated approach in studying ground movement in hilly regions.

Jan 1, 1998

By David Newman

"Horizontal stress can have a profound effect on the stability of an underground limestone mine. The presence of horizontal stress is usually determined once the mine has been developed and the orientation of headers and crosscuts are well established. Multiple attempts are typically made to control roof falls without re-orienting the mine. Once the decision has been made to change the orientation, pillar centers, mine opening widths, and the question of how to determine the correct orientation must be answered.A case history is presented to illustrate how geologic structure, ground conditions and roof falls in adjacent mines, the World Stress Map (Heidbach et al., 2016), in-mine measurement of “cutter” roof orientation, the orientation of strata offset (cats eyes) within borescope holes, and the diametral deviation method of determining horizontal strain from drill core were used to establish the most likely range of horizontal stress.The main headers were re-orientated in a direction parallel to the median of the range of horizontal stress. The crosscuts were angled 60° to the headers to avoid being perpendicular to the horizontal stress direction. Pillar centers and opening widths were increased in the favorable stress direction of the mains and decreased in the less favorable crosscut orientation. The major principal horizontal stress magnitude was estimated using the strain measurements from the diametral deviation method and elastic modulus obtained through testing.INTRODUCTIONOver the past decade, there has been a significant increase in the number of underground stone mining operations in the United States. As stripping ratios at surface quarries become uneconomical and reach the extent of the mineral boundary, coupled with the encroachment of urban development on previously rural mining operations, the remaining mine reserves are best accessed through underground development.Although the majority of underground limestone mines in the Midwest are in relatively flat lying deposits with minimal geologic structure, many Appalachian mines are in folded and faulted environments. Tectonic horizontal stresses associated with multiple orogenic episodes are locked in the formation and are released as the underground mine is developed.A common misconception is that horizontal stress impacts are more prevalent at shallow depths where the ratio of horizontal to vertical stress may be high. However, field observations and academic research indicates that horizontal stress conditions may be encountered at any depth due to the tectonic compression of the limestone formation (Esterhuizen et al., 2007; Dolinar and Esterhuizen, 2007; Iannacchione et al., 2003; Slaker, Murphy, and Miller, 2017; Kuhnhein and Ramer, 2004). This paper outlines mine design and layout guidelines for the mitigation of horizontal stress impacts on underground stone mining operations through a case history example. This approach to mine planning and the ability to anticipate horizontal stress can significantly improve future production of multiple levels (Newman and Newman, 2019). As underground stone production continues at deeper depths and in more geologically and geometrically complex mining conditions, an emphasis on ground control and the anticipation of horizontal stress can provide safer and more productive single and multiple level mining operations."

Jan 1, 2019

By Van Price

Some technical developments of the National Uranium Resource Evaluation Program which are of general application in geochemical exploration are being studied. Results of stream water and suspended and bottom sediment analyses are compared for an area near Williamsport, Pennsylvania. Variations of uranium content of water samples with time in the North Carolina Piedmont are seen to correlate with rainfall. Ground water samples from coastal and piedmont areas were analyzed for helium. All media sampled provide useful information when properly analyzed and interpreted as part of a total geological analysis of an area.

Jan 1, 1979