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By John F. Beesley

INTRODUCTION This paper discusses the design of the subsurface nuclear waste repository at Yucca Mountain, Nevada; and possible concepts for construction of the subsurface facility. Subsurface construction at Yucca Mountain is planned to last for 20 or more years, and may be accomplished using tunnel boring machines (TBM), drill and blast methods, raise bore machines, and roadheaders. The design of the subsurface facility includes approximately 107 km (66 miles) of tunnels and drifts. The vast majority of the repository will be excavated with TBMs. Design and construction concepts for the subsurface repository discussed in this paper are based on the License Application that was submitted to the U.S. Nuclear Regulatory Commission (NRC) by the U.S. Department of Energy (DOE) on June 3, 2008. The License Application was subsequently docketed by the NRC in September 2008. When a Construction Authorization is received from the NRC, notices to proceed with subsurface construction at Yucca Mountain will be issued by DOE. The Yucca Mountain site is located in the Mojave Desert approximately 150 km (90 miles) northwest of Las Vegas, Nevada. The site is on federal land in southern Nevada and is shown in Figure 1. Yucca Mountain is a ridge of volcanic rocks com-posed primarily of solidified volcanic ash. Previous underground construction work at Yucca Mountain included excavation of two tunnels using two different TBMs. The first tunnel, the Exploratory Studies Facility (ESF), is a 7.62 m (25 ft) diameter tunnel that is 7,877 m (25,843 ft) long and was described by Morris and Hansmire at the Rapid Excavation and Tunneling Conference (RETC) in 1995. The second tunnel, known as the Enhanced Characterization of the Repository Block (ECRB), was a TBM drive of 5.0 m (16 ft, 5 in.) in diameter and 2,681 m (8,796 ft) long. The second tunnel was excavated in 1998 and was described by Fulcher, Eastlund and Copeland at RETC 1999 and is named the East?West Cross Drift in that paper. (These previously excavated tunnels are shown in Figure 2.) In the volcanic rock formation where the vast majority of the planned repository will be con-structed, previous tunneling conditions were generally very good.

By Eduardo Lozano, Vilem Petr

The use of explosives bring countless benefits to our everyday lives in areas such as mining, oil and gas exploration, demolition or avalanche control. However, because of the potential destructive power of explosives, strict safety procedures must be an integral part of any explosives operation. The goal of this paper is to provide a solution against the hazards which unfortunately accompany the use of explosives. For this reason, a blast shield is specifically designed and tested for protecting personnel against these unpredictable effects. This document will develop a complete analysis answering the following questions: what are the potential hazards from an air blast; what are their effects; and how can we be protected against them. In order to answer these questions, theoretical, analytical, and numerical calculations are performed. Finally, a full blast shield prototype is tested under blasting conditions proving its effectiveness as a safety device while explosives are used.

Jan 1, 2015

By Alastair Grogan

In October of 2002, the author was retained by Public Works and Government Services Canada, on behalf of the Department of National Defense, to design, construct and test the effectiveness of a bubble curtain system at an underwater demolition range, near Victoria, BC. The purpose of the bubble curtain was to reduce the potential for fish mortalities at the site. This paper presents some of the elements of the design, along with the results of overpressure monitoring during blasting and compares the results of fish mortality and animal behaviors with and without the bubble curtain in operation.

Jan 1, 2005

By Lorie M. Dilley

Alaska Village Electric Cooperative (AVEC), an electric utility cooperative providing power to 51 Alaska villages, has made a concerted effort to install wind turbines in the villages they serve in an effort to mitigate the growing costs of electrical power generation. The subsurface soils in several of these villages consist of sands and silts with ground temperatures of between 30°F and 32°F. The presence of warm, degrading permafrost in three of the villages has required innovative foundation designs, including the use of helical piers and piles to support steel and concrete wind turbine foundations. The design of the deep foundations had to account for the effects of degrading permafrost likely resulting from observed climate change patterns. Uplift forces imposed on the foundations were approximately 100 kips per pile. Uplift pile load testing was conducted on the installed piers and piles in order to determine the actual working load that each pier or pile could sustain. In addition, pile driving analyzer testing was conducted on several piles installed in the permafrost and compared to pile load tests. Results indicated that the installed piers and piles achieved the necessary capacity with sufficient factors of safety. Thermosyphons were installed near the foundations in order to limit the effects of climate change on the permafrost. The two to four wind turbines in each of the three villages are currently operational. Refinement of the design based on the pile testing from the first village to the third has decreased the cost of the tower foundations and improved our understanding of designing for warm, degrading permafrost.

Jan 1, 2010

By Belinda F. Arbogast

Reclaimed mine sites have been evaluated so that the public, industry, and land planners may recognize there are innovative designs available for consideration and use. People tend to see cropland, range, and road cuts as a necessary part of their everyday life, not as disturbed areas despite their high visibility. Mining also generates a disturbed landscape, unfortunately one that many consider waste until reclaimed by human beings. The development of mining provides an economic base and use of a natural resource to improve the quality of human life. Equally important is a sensitivity to the geologic origin and natural pattern of the land. Wisely shaping our environment requires a design plan and product that responds to a site's physiography, ecology, function, artistic form, and public perception. An examination of selected sites for their landscape design suggested nine approaches for mining reclamation. The oldest design approach around is nature itself. Humans may sometimes do more damage going into an area in the attempt to repair it. Given enough geologic time, a small-site area, and stable adjacent ecosystems, disturbed areas recover without mankind's input. Visual screens and buffer zones conceal the facility in a camouflage approach. Typically, earth berms, fences, and plantings are used to disguise the mining facility. Restoration approaches the best land use as restoring to its original condition. Rehabilitation targets social or economic benefits by reusing the site for public amenities, most often in urban centers with large populations. A mitigation approach attempts to protect the environment and return mined areas to use with scientific input. The reuse of cement, building rubble, and macadam meets only about 10% of the demand for aggregate. Recognizing the limited supply of mineral resources and encouraging recycling efforts are steps in a renewable resource approach. An educative design approach effectively communicates mining information through outreach, land stewardship, and community service. Mine sites used for art show a celebration of beauty and experience-abstract geology. The last design approach combines art and science in a human-nature ecosystem termed integration. With environmental concerns, an operating or reclaimed mine site can no longer be considered isolated from its surroundings. Site analysis of mine works needs to go beyond site-specific information and relate to the regional context of the greater landscape. Understanding design approach can turn undesirable features (mines and pits) into something perceived as desirable by the public.

Jan 1, 1999

By Randall C. Divito, Craig R. Eckdahl, Bruce D. Wagener, Joseph Klejwa

The existing Central City Tunnel was built primarily in the 1930s with a small portion as old as the 1880s. It conveys stormwater in downtown Minneapolis. It is a 4,400-ft long tunnel located 80 feet underground. The Central City Tunnel has experienced surcharging and surface overflows during heavy rainfall events. This paper presents the details of tunnel and shaft design for the new Central City Parallel Tunnel to mitigate the overflows. The design considered hydraulics and geotechnical engineering for the structural geologic conditions including the weak Saint Peter Sandstone and overlying strong Platteville Limestone. Ground conditions resulted in tunnel designs including large flat-back box tunnels and unique cathedral-shaped tunnel sections.

Jun 13, 2023

By A. D. S. Gillies

The use of refuge chambers for use in handling underground emergencies is an issue of topical relevance within the US mining industry. Chamber design is of importance to meet some new safety requirements of US federal and some state government mine regulations. A review has been undertaken of a steel mine refuge chamber design to predict what will be internal temperature within the chamber over an extended period with miners present? The design has been examined for the situation when the chamber is sited in still mine air. Spreadsheets have been developed to allow various design assumptions to be tested. The evaluation has been undertaken using thermodynamic heat transfer models with some assumptions specified to produce a model of appropriate simplicity but with adequate degree of accuracy. Under normal still air conditions it can be seen that internal chamber conditions rise quickly to often arduous conditions. There will always be quite a few assumptions necessary in complex heat transfer process evaluations. Some important refuge chamber design parameters are: ? External surface area of the chamber, its wall thickness and construction. ? Metabolic heat generated and number of persons making use of the chamber. ? The temperature of the external mine atmosphere to the chamber over the year and the influence of geothermal gradient on temperature at depth. ? The maximum internal chamber Apparent Temperature considered safe. ? The distance inside the underground mine and adjacent ventilation conditions.

Jan 1, 2012

By Mark Spence, Tom Lardner, Matthew Janes

"IntroductionThe design-build method streamlines project delivery through a single contract between the Contract manager and the design-build team. The design-build method places emphasis on collaborative project management between design and construction disciplines to minimize project schedule, reduce costs, encourage balance risk amongst the design-build team. Since 1985, the percentage of nonresidential design and construction projects has increased from 5% to 45%.1A project carried out in Edmonton, Alberta, Canada will be used as an example to illustrate the challenges of the design-build project delivery method and the merits of establishing a GBR. The project involved a complex slope stabilization as part of an extensive freeway widening. At the project location the roadway was being widened within the base of a historic stream valley into a steep slope with a history of a previous slope failure. The slope was to be steepened through the installation of a series of 14 interlocking arc structures constructed half way up the slope. Access and schedule proved critical to the successful completion of the project.Geotechnique and Site HistoryThe geotechnical investigation undertaken for the site included six boreholes drilled at the crest of the slope to depths ranging from 14.5 m to 30.2 m. Laboratory testing of the soil samples included direct shear tests, Atterberg limits and grain size analysis. The geotechnical report also referenced a previous geotechnical investigation that was carried out in response to a failure of the slope in 1971."

Jan 1, 2015

By Giuseppe M. Gaspari, Tamara Kondrachova

Contract practices affect cost and schedule of tunneling works, impacting risk allocation between Owners and Contractors. The Authors compiled a dataset of projects constructed in the Toronto Area between 1990–2020 procured either Design-Build or Design-Bid-Build. Data were analyzed identifying independent cost variables across the two methods. Overall industry efficiency further comparison with historical information demonstrates the costs of engineering ongoing escalation due to rising trends in environmental requirements and public consultations stirred through modern communicative platforms. These hard to predict and estimate costs need to be included in the risks evaluated and managed by Owners and not by Contractors

Jun 13, 2021

By Leykam Chris J., Jacobs Scott. A.

"Construction of the New NY Bridge over the Hudson River 25 miles north of New York City is one of the largest civil infrastructure projects presently underway in the United States (formerly Tappan Zee Hudson River Crossing). The $3.14 billion Design-Build contract is also the largest ever awarded by the state of New York using an Alternative Project Delivery method, and the first major public project to use Design-Build. The new 3.1 mile long bridge will replace the existing Governor Malcolm Wilson Tappan Zee Bridge with a modern twin crossing featuring: Iconic side by side cable stay main spans; significant deck widths accommodating eight lanes of regular traffic, wide shoulders, and a shared use pedestrian and bike path; foundation with excess capacity to fully support a future rail bridge; more than 1,000 large diameter pipe piles driven in deep glacial deposits; drilled shafts installed through steep blast-rock slopes on the east shore landings. Geotechnical challenges included varied bedrock and glacial till surfaces with steep slopes and depths in excess of 750 ft.The purpose of this paper is to highlight major features of the New NY Bridge project with specific focus on the design and construction of the foundations supporting the approach and main span structures from abutment to abutment, provide background on alternative project delivery in NY, as well as provide an overview of the design-build process as it was applied to foundation delivery.The 3.1 mile Governor Malcolm Wilson Tappan Zee Bridge was constructed across the Hudson River connecting Nyack and Tarrytown (Rockland and Westchester Counties). Construction started in March 1952 and was completed in 1955 for a cost of $81 million. The seven lane crossing first opened to traffic on December 15, 1955 and coincided with the opening of a 28 mile segment of highway I-87 / I-287 between Suffern NY and Yonkers NY. The bridge is part of the extensive 574 mile New York State Thruway road system owned and operated by the New York State Thruway Authority (NYSTA)."

Jan 1, 2016

By Morgan M. Sears, lhsan B. Tulu, Ted M. Klemetti

"Why do some room and pillar retreat panels encounter abnormal conditions? What factors deserve the most consideration during the planning and execution phases of mining and what can be done to mitigate those abnormal conditions when they are encountered? To help answer these questions, and to determine some of the relevant factors influencing the conditions of room and pillar (R&P) retreat mining entries, four consecutive R&P retreat panels were evaluated. This evaluation was intended to reinforce the influence of topographic changes, depth of cover, multiple-seam interactions, geological conditions, and mining geometry.This paper details observations made in four consecutive R&P retreat panels and the data collected from an instrumentation site during retreat mining. The primary focus was on the differences observed among the four panels and within the panels themselves. The instrumentation study was initially planned to evaluate the interactions between primary and secondary support, but produced rather interesting results relating to the loading encountered under the current mining conditions. In addition to the observation and instrumentation, numerical modeling was performed to evaluate the stress conditions. Both the LaModel 3.0 and Rocscience Phase2 programs were used to evaluate these four panels. The results of both models indicated a drastic reduction in the vertical stresses experienced in these panels due to the full extraction mining in overlying seams when compared to the full overburden load. Both models showed a higher level of stress associated with the outside entries of the panels. These results agree quite well with the observations and instrumentation studies performed at the mine.These efforts provided two overarching conclusions concerning R&P retreat mine planning and execution. The first was that there are four areas that should not be overlooked during R&P retreat mining: topographic relief, multiple-seam stress relief, stress concentrations near the gob edge, and geologic changes in the immediate roof. The second is that in order to successfully retreat an R&P panel, a three-phased approach to the design and analysis of the panel should be conducted: the planning phase, evaluation phase, and monitoring phase."

Jan 1, 2016

By C Garrido, J Barrera, H Alvarez, L Perez, S Ramirez

In recent years, there has had a greater recurrence of studies and projects that consider tailings filtration followed by dry stacking to reduce the consumption of fresh water, the space required for disposal, and, eventually, to reduce the costs of the project. In addition, this technique could be required to meet new environmental restrictions to extend the life-of-mine of existing plants or to enable the development of new projects, especially in areas of high social interest. This article is intended to describe the most relevant technical aspects of the design and implementation of an iron ore tailings filtering system and its final overland disposal as well as physical and metallurgical surveys, and laboratory and pilot testing. Furthermore, it is presented how these activities are inserted in the project development to rationalise the resources. The case under study considers an iron mineral wet magnetic concentration processing plant. The outcome tailings are dewatered by means of thickeners, where the overflow water is recycled back to the plant. The underflow slurry is pumped into intermediate storage tanks before proceeding with further dewatering and final disposal. The project consists of a tailings filtration plant, belt conveying systems, a temporary stockpiling system, trucking loading and transportation system, moisture-conditioning facilities (spreading and airing), and final disposal facilities (compacting). Due to the stickiness of the filtered tailings that governs the belt conveying system design, the operating moisture range must be established. Besides, proper technical aspects such as planning, executing, and analysing both the laboratory and the pilot testing data to validate process design parameters; selecting filters; defining spare filtering capacity; handling the out-of-range filtrated moisture; sizing the belt conveying system; configuring the equipment involved, must be considered.

Nov 8, 2021

The purpose and current practice of cable trusses in underground coal mines is briefly outlined and details of various cable truss designs are presented. The main part of the paper describes the in-situ performance of cable trusses installed as secondary supports in gateroads and recovery roads of longwall coalfaces. The performance analysis is based on the results of in-situ monitoring carried out at a number of sites at two underground coal mines within Australia. Truss performance has been assessed as load developed in relation to roof convergence, face position and time. Additionally, the influence of strata conditions, installation pattern/density, roadway layout and geometry have been taken into account. An analytical model has been developed to predict truss loads. The principal variables are listed and the basis of the model is described. Based upon behaviour observed in the field the model has been progressively upgraded and validated against measured performance. Guidelines on truss performance and factors which influence it are presented and the implications of these to the use of cable trusses is discussed. Possible methods for improving truss performance in certain strata conditions are outlined and some comments are made on the value of cable trussing compared to cable bolting in these situations,

Jan 1, 1992

By Fuller P. G

The purpose and current practice of cable trusses in underground coal mines is briefly outlined and details of various cable truss designs are presented. The main part of the paper describes the in-situ performance of cable trusses installed as secondary supports in gateroads and recovery roads of longwall coalfaces. The performance analysis is based on the results of in-situ monitoring carried out at a number of sites at two underground coal mines within Australia. Truss performance has been assessed as load developed in relation to roof convergence, face position and time. Additionally, the influence of strata conditions, installation pattern/density, roadway layout and geometry have been taken into account. An analytical model has been developed to predict truss loads. The principal variables are listed and the basis of the model is described. Based upon behaviour observed in the field the model has been progressively upgraded and validated against measured performance. Guidelines on truss performance and factors which influence it are presented and the implications of these to the use of cable trusses is discussed. Possible methods for improving truss performance in certain strata conditions are outlined and some comments are made on the value of cable trussing compared to cable bolting in these Situations.

Jan 1, 1992

By Allan Breitenbach

Leaching has been used since the 1600s on unlined ore dumps and since the late 1970s on lined leach pads for the recovery of metals from mined ore, the latter typically called ?heap? leaching and the former ?dump? leaching. Modern day run-of-mine (ROM) or crushed ore heaps are stacked in controlled lifts on lined leach pads and irrigated with a solvent solution (dilute alkaline cyanide for precious meals, dilute sulfuric acid for base metals and uranium). Conventional lined leach pads store process solutions and any storm water, snow melt and cumulative wet season surplus water by gravity flow to external ponds. Impounding valley leach pads (also known as valley fill heaps) differ from conventional leach pads by storing various combinations of process liquid solution and surplus water within internal ponds by using the interstitial pore volume of the ore. While impounding liquids within the heap is simple in concept, impounding leach pads are more complicated for construction and containment compared to conventional leach pads with external ponds.

Jan 1, 2012

By A. D. S. Gillies, A. Haghighat

"A study has been undertaken at the Missouri University of Science and Technology (MS&T) limestone Experimental Mine to determine new fans set up and wiring options.to install additional mine ventilation capacity. Selection for main fans has been undertaken according to the mine’s required performance specifications and fan characteristics. Available fans for ventilating the mine are Joy and Alphair axial fans each of 24 kW each and two Spendrup booster fans of 12 kW each. The installation of main mine fans on the surface and underground entails numerous considerations. Design of a ventilation network for the Experimental Mine incorporating surface and booster fans has been accomplished using Ventsim Visual program software. The ventilation network has been separated into two segregated parts. A main surface fan and a booster fan have been used in each segregated part of the network. The mine has had a vane axial Joy fan in place for many years. The Alphair 4800 VAX 1800 full blade adjustable pitch vane axial fan was selected and installed as the other surface fan and eventual replacement for the Joy fan. Main surface fans have been connected individually to booster fans in series. The Alphair main surface fan has been installed vertically. Four different wiring options and related cost estimations for addition of the new main fans to the ventilation network have been considered. The analysis resulted in an innovative steel frame design used to allow the fans, when necessary, to be moved to the side of the shaft so that blast pressures do not damage the blades. INTRODUCTION Main fans are the heart of a mine’s ventilation network and play a key role in supplying required airflow (Haghighat, 2014). The Missouri S&T Experimental Mine has been developed in uniform limestone with few stratigraphic features. The mine floor is approximately horizontal and water drains well. A study has been carried out on MS&T Experimental Mine. Selection of main fans has been undertaken according to the mine’s required performance specifications and fan characteristics. Ventsim Visual computer simulation has been used to assist in design of the ventilation network. Wiring circuits, fan foundations and flexibility have been considered as the three main parameters for surface fan installation at the Experimental Mine. Two surface and two underground wiring options and three surface set up options and related cost estimates for the new surface fan system were investigated. Frequent use of explosives in the mine occurs throughout each year. Flexibility in changing the position of a surface fan is important. A number of options have been considered for the location of a vertical main fan positioned on the upcasting shaft. The mine is used for a variety of purposes and flexibility has a high priority amongst design considerations."

Jan 1, 2015

By Cameron J. Clayton

Cumberland Resources Ltd. is currently planning to develop the Meadowbank Gold Project located some 70 km north of Baker Lake, Nunavut in the eastern Canadian Arctic region. The Meadowbank Gold Project currently consists of up to 6 main gold bearing deposits within relatively close proximity to one another which are planned to be mined primarily as a truck-and-shovel open pit operation and using conventional gold milling and extraction. The mining plan indicates that approximately 20 million tonnes of ore will be mined over a mine life of 8 to 10 years. The operation will generate approximately 160 million tonnes of mine waste rock and about 20 million tonnes of tailings. The site is located in an area of continuous permafrost with mean annual average air temperature of -11 °C and average annual precipitation in the range of 100 to 200 mm. Lakes cover a large portion of the site, including some of the ore deposits. The location of the site, and the physical environment, pose challenges to development. This paper presents some of the designs considered to effectively manage and utilize the waste products of mining at the project.

May 1, 2004

By C. J. Clayton, A. J. Haynes, D. A. Hickson, B. Thiele

The Meadowbank Gold Project, formerly owned by Cumberland Resources Ltd. and currently owned by Agnico Mines Ltd., is currently being developed approximately 70 km north of Baker Lake, Nunavut, in the eastern Canadian Arctic region. The Meadowbank Gold Project currently consists of a series of gold-bearing deposits within relatively close proximity to one another, which are planned to be mined primarily as a truck-and-shovel open pit operation using conventional gold milling and extraction. The mining plan indicates that approximately 20 million tonnes of ore will be mined over a mine life of eight to ten years. The operation will generate approximately 160 million tonnes of mine waste rock and about 20 million tonnes of tailings. The site is located in an area of continuous permafrost with mean annual average air temperature of -11°C and average annual precipitation in the range of 100 to 200 mm. Lakes cover a large portion of the site, including some of the ore deposits. The location of the site and the physical environment pose challenges to development. This paper presents some of the designs considered to effectively manage and utilize the waste products of mining at the project. Note that volumes, tonnages, construction concepts, and data presented in this paper are accurate for the time of writing and are subject to change and modification as the project progresses, additional modelling is carried out, and additional data are obtained.

Jan 1, 2007

By James P. Ludwig

While we are all aware of the need for reclamation of mine sites, few managers and engineers seem to be aware that good reclamation begins with the earliest plans for mining and processing of ores. Far too often the attitude that reclamation is an add-on to worry about at the end of the mining process dominates the thinking of mine engineers and management, A common result is that the reclamationist can be faced with mining and waste disposal designs that are nearly impossible to deal with effectively from an ecological perspective. Everyone of us has been victimized by the down time and maintainence cost that resulted from the purchase of an outwardly attractive, but poorly designed piece of equipment. When confronted by design defects in equipment, a distraught owner can always trade it in, call a consumer advocate, or follow up one of the "lemon laws" at either the federal or state level. A poorly designed mine for reclamation purposes usually cannot be treated either with ease or cost effectiveness. Good reclamation can be effectively prevented by the designs used when the mine was planned. The purpose of this paper is to share some of the experiences our firm has had with reclamation projects at mines in the Upper Midwest as these were influenced or controlled by mine design decisions. My aim is to sensitize mine planners and managers to planning processes they should consider, and hopefully use, early in the mining process to assure successful reclamation during and after mining. Many of the examples I will cite are from experience gained at the recently closed Jackson County Iron Company taconite operation at Black River Falls, Wisconsin. I am particularly grateful to Mr. Vern Metzger, mine manager at JCIC, for his unflagging support of good reclamation practices, employee training programs (which have included reclamation techniques), and his forebearance to put up with our group of ecologists. I realize that this was a time when there were significant internal and external pressures to cut all costs including reclamation efforts. The collaboration has been successful as you will soon see.

Jan 1, 1984

By J. M. Keane

SMEThis loaner is concerned with important criteria relative to the design of small flota¬tion concentrators. For the purpose of this discussion a small flotation concentrator is defined as a facility having a designed ore feed rate of 1,000 metric tons per day (MTPD), or less. The decision to design and construct a small flotation concentrator is the culmination of a series of logical steps relative to the ex¬ploitation of a potential ore body. The information required for a rational and timely decision regarding plant design and construction is usually contained in a feasibility report. The information required in a thorough feasibility report has been summarized (1) (2) as follows: Type of mine or plant and proposed daily, monthly, and yearly production of all intermediate and final products. Quantity of indicated ore reserves. Location of project illustrated by a map showing surroundings, trans-portation facilities, and existing utilities.

Jan 1, 1980