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By D Blair, L Fergusson, G Barros

"The purpose of this paper is to present the findings of a waste rock remediation program conducted at a gold mine in New South Wales (NSW) over a six-year period. The treatment of waste rock dumps included the longitudinal results of one-off applications using: ViroMine Technology, including the application of a chemical reagent called Terra B, which is a benign, clay-like substance derived from processed bauxite and other sources lime and biosolids (added for nutrient value) clay capping and topsoil compared treatment outcomes from these three approaches to a control.Parameters measured in the program included leachate pH, total actual acidity (TAA) and chromium reducible sulfur (CRS), Al, Cd, Cu, Fe, Mn, Ni, Pb, Zn, and tree height and vegetative cover density with data collected at regular intervals over a six-year monitoring period. Findings over the life of the study indicated, for example, that leachate pH in the control area was 4.5 in year 1 falling to 4.0 by year 6; pH in the lime and capping treated waste rock was initially raised to about 5.5 after treatment but fell to 5.0 within 24 months and remained a low 4.7 by year 6; pH in the Terra B waste rock was 6.8 in year 1 immediately after treatment, and actually increased to 7.3 by year 6 with no further treatment. This finding is of relevance because it effectively profiles the acidity curves of waste rock control, lime, and capping applications, and shows that they decline over time, despite an initial æpH shockÆ to the solids as measured by TAA and CRS in the case of lime. Similar treatment curves were observed for heavy metal leachates. Tree height and vegetative cover density indicated that with increasing acidity in the waste rock dump, the lime and capping options did not allow healthy revegetation, but in the Terra B treated areas tree growth and density were comparable to background, undisturbed forest levels.is needed with respect to tailings management, based on a novel integrated research framework.CITATION:Fergusson, L, Blair, D and Barros, G, 2012. Sustainable waste rock remediation and revegetation - A real-world longitudinal study comparing ViroMine technology to standard applications and doing nothing, in Proceedings Life-of-Mine 2012 , pp 249-258 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By A. L. Irwin

THE disposal of tailing or waste material, which is generally a very large proportion of the ore treated, is a major problem in the location and operation of any concentrating enterprise and especially so where the life of the operation is expected to continue for many years. Many factors need to be taken into consideration in the selection of a tailing site, chief among which are economical handling of the material, subsequent re-treatment of the tailing, and precaution against stream pollution by waste water. The final location of many mill sites bas been governed largely by the selection of a sui table area for tailing storage. The Sullivan concentrator of the Consolidated Mining and Smelting Company is situated about three miles from the Sullivan mine at Kimberley, B.C., and one of the deciding factors in its location at this distance from the mine was the availability of a suitable area in which tailing could be deposited. In view of the indicated long life of the property, a far-sighted policy bad to be adopted in the matter of tailing storage, for not only would it be necessary to accumulate a huge tonnage of finely ground material, but also reclamation for iron recovery at some future date bad to be considered. Some idea of the extent of the problem may be grasped when it is noted that, by the end of 1938, over 18,000,000 tons of tailing bad been impounded in an area of some 200 acres.

Jan 1, 1939

By Samer Sadek, Brian Hagan

We are thrilled to welcome you to the 2025 Rapid Excavation and Tunneling Conference (RETC), which will be held in Dallas, TX. This year’s conference will showcase the continued trend of strong industry interest, as there will be a record setting 115 papers being presented over the course of three days. The set of papers compiled in this book captures the latest and greatest information on a broad array of topics within our fascinating tunneling industry. We hope that the compilation of selected papers in this book will provide a comprehensive recap of the conference while also providing a source of future reference for contractors, engineers, and anyone in general who is a student of our beloved and unique industry. Since its inception in 1972, RETC has been the preeminent tunneling forum to promote ideas, tell stories, share lessons learned, and promote new technologies. RETC prides itself on its focus towards highlighting real-world experiences and practical ideas, with the intent to help the entire industry learn from one another and grow. The need for us all to stay sharp and remain on the cutting edge of technology has never been stronger – the technology and ideas that have been applied in aerospace are now attempting to mix with tunneling, and the advancement of AI continues to permeate all industries. However, no amount of technology or AI can fully replace the human element, and in our tunneling industry, the human element is key and is what sets us apart. In tunneling, every project is different, because the ground is always different. We can only take what the ground will give us, and we must rely on our past experiences to get through present day challenges. Most importantly, we must rely on each other. This is the heart of what RETC is all about. For those of you attending this conference, we encourage you to attend as many sessions as possible and engage with your colleagues to discuss during the breaks in between sessions. This sharing of ideas is what keeps us connected and helps to expand our industry. Please also try to engage with the scholarship students and the newcomers who will be in attendance, as it is the new ideas and fresh energy from the next generation that will continue to make our industry thrive into the future. The program chairs thank and greatly appreciate the efforts made by our session chairs, co-chairs, authors, the members of the RETC Executive Committee, and most importantly the SME staff towards making this RETC possible.

Oct 1, 2025

By Jason Clarke, Glen Trainor

As the mining industry faces increased challenges with declining ore grades and harder to access deposits, operating mine sites in an environmentally responsible and economically viable manner will require innovations that improve efficiency in energy logistics, and automation. Technological advancements in mining have been successful primarily because of the willingness and capability of these solutions to share information with one another, for example OEM payload systems sending information to Fleet Management Systems, and in turn Fleet Management Systems interfacing to ERP systems. To promote and facilitate the sharing of data, there has been a push towards open standards with initiatives led by organizations like ISO, ISA, EMESRT, and GMG. These efforts are aimed at creating a more collaborative and interoperable environment within the sector. However, when it comes to implementing autonomous solutions, a different trend dominates— closed-stack solutions. These closed stack solutions not only prohibit a mine site from selecting best-of-breed solutions, by blocking the competition from entering the market, they also risk slowing innovation that could help overcome the challenges the mining industry faces. Open Autonomy, an internationally published standard that allows any FMS to work with any Autonomous solution, breaks this closed-stack approach and invites competition from other industries. This competition comprises of autonomous suppliers from other industries and manufacturers of smaller, civil-sized haul trucks. The availability and capabilities of these smaller-sized autonomous haul trucks will help tackle the challenges of responsibly and economically mining lower quality ore grades and mining harder to access deposits.

Feb 1, 2024

By R. J. Sweigard

Stabilization of slopes on abandoned mine land (AML) invariably involves some channelization to control surface drainage. Typically, these channels are lined with riprap or gabions, depending on gradient and expected flow rate. The conventional treatments pose a problem since they require frequent maintenance and replacement at times. Soil bioengineering presents an alternative to the conventional measures. In soil bioengineering, living woody plant material forms the main structural component in systems designed to prevent shallow mass slope failures, surface erosion, and channel bank erosion. An experimental application of soil bioengineering techniques was designed and implemented at an AML site in eastern Kentucky. The design consisted of live fascines and live stakes using willow branches installed with coir geotextile. Channel gradient, length, and cross-section were considered in the design.

Jan 1, 1998

By Stuart Hardy, Xiangbo Qiu

The South Bank Place project comprised the redevelopment of the iconic Shell Corporation headquarters in Waterloo, located on the Southbank of the River Thames in central London. The site was originally developed in the 1950’s and due to the monitoring of the underlying Bakerloo Line tunnels by the Building Research Station it has become a seminal case history for the long term swelling behaviour of London Clay. The redevelopment, undertaken by a joint venture of Canary Wharf Group and Qatari Diar, included demolition of the existing building (with the exception of the main towers) retention of the existing basement structure and the construction of eight new mixed use buildings, up to 31 storeys in height. The foundations for the new buildings varied according to the building height and the below ground constraints. Two of the buildings are partially founded in reused under reamed piles that were installed as part of the original 1950’s development. The paper describes the novel methodology developed to assess the re-use of the under reamed piles which builds on the guidance published by CIRIA and the BRE for straight shafted piles. The paper also describes the physical investigations and numerical analyses undertaken as part of the assurance process and the procurement of latent defect insurance by the client.

May 1, 2022

By M. J. Raffaldi, K. W. Harris, K. A. Perry

"Highwall miners have been widely used to extract additional coal reserves from existing surface operations, particularly on contour operations in the Appalachian coalfields. Using a continuous miner cutting head, coal may be extracted from significant depths (such as 150 m), leaving behind an array of web and barrier pillars with the purpose of maintaining highwall stability. This method inherently involves elevated risks to both equipment and personnel due to proximity to and increased exposure time near highwalls. As a result, modern operations should actively design web and barrier pillars to maximize extraction while providing adequate stability. The ARMPS-HWM software, an empirical-based program created for the design of web and barrier pillars at highwall mining operations, is one such approach. The calculated stability factor is compared with empirically established guidelines produced from examining case histories.The ARMPS-HWM program is a handy tool for initial design, but understanding the site’s structurally significant geologic features and geomechanical behavior is important and may potentially increase extraction. We created a two-dimensional numerical model using FLAC3D and calibrated it to ensure pillar strength, closely following the Mark- Bieniawski formula for a typical range of pillar geometries and overburden properties. The development of pillar stresses along a highwall panel was then numerically investigated as mining progressed, and the stress distribution between barrier pillars was found to be asymmetric, which can result in an over-design of the closeout web pillars if tributary area loading is assumed. Finally, the importance of adequate barrier pillar stability is highlighted."

Jan 1, 2014

By Anthony L. Reynolds, Clifford J. Wren

"The adoption of a significant pile testing regime, the use of Eurocode 7 as the design standard, the development of lean construction techniques, and lateral thinking in overcoming some considerable construction challenges allowed Stent Foundations to construct the foundations for the new Wembley Stadium, London, on time and within budget. In addition to the piling works for the main stadium, and after significant design development, a large number of extra piles were required to raise the new iconic roof Arch to its final position some 133 metres above the ground. A 1,400m long contiguous bored pile wall was also constructed to allow for excavation and formation of the new pitch. INTRODUCTIONHjstorjcal lntrodyctionWembley Stadium is the 'home of English football'. As long ago as the 1880's, Wembley Park leisure grounds had football pitches and running tracks.In 1918 the British Government began planning a British Empire Exhibition with a stadium as its centrepiece. The Exhibition area covered 219 acres and the area on which a former abandoned tower called Watkins Folly had stood was chosen as the site for the new stadium (http://www.wembleystadium.com).The Empire Stadium, as it was originally known, was designed by architects Sir John Simpson and Maxwell Ayerton and the engineer Sir Owen Williams. It took just 300 days to complete at a cost of £750,000 ($1.4m), and was built using 25,000 tons of ferro concrete, 1,000 tons of steel, and over half a million rivets.The Empire Exhibition was a remarkable event, containing fountains, lakes, gardens, and many pavilions, each representing the architectural style of the countries exhibiting. It was opened on 23rd April 1924 and the final attendance was over 27 million, with 4.5 million admissions to the Empire Stadium alone."

Jan 1, 2005

By Derek V. Ellis

Sediment Quality Guidelines can provide target values that should not be exceeded when seabed deposits are disturbed for mining, waste discharge or other purposes. Three sets of Guidelines have appeared in 1994 and 1995: US NOAA (updated from 1991), Environment Canada (EnvCan) and Equilibrium Partitioning (EqP) developed in the UK from US Water Quality Criteria. The US NOAA and EnvCan Guidelines have been developed by comparing many experimental and site data sets, and have concluded that levels below which effects rarely occur, or above which probably will occur, are useful guidelines. US NOAA uses the terms ERL and ERM for these two levels, and EnvCan TEL and PEL. The EqP concept is that a value can be calculated below which trace metals present cannot raise the concentration in the interstitial water. There are some problems in comparing units, but the comparison shows in general that the EnvCan levels are less than, and down to half of, the US NOAA levels. EqP levels vary but are generally fairly close to US NOAA ERL levels, with one major exception. The EqP level for mercury is far lower than either US NOAAor EnvCan levels, at 0.008 mg kg-1 compared to 0.15 (ERL) and 0.13 (TEL) mg kg-1 respectively. Comments will be solicited on how such differing Guidelines should be used site-specifically for environmental management at mining operations, (1) in the regions for where they were developed, and (2) elsewhere.

Jan 1, 1995

By S. Kim Juniper

Ocean observatory technologies permit uninterrupted, real-time observation of dynamic seafloor environments such as gas hydrate deposits and hydrothermal vent fields that are of both scientific and economic interest. Such observations enable new discoveries of linkages between physical, chemical and biological processes and could permit continuous monitoring of environmental variables during mining operations. Ocean Networks Canada operates the NEPTUNE and VENUS cabled observatories in the Northeast Pacific Ocean. The offshore NEPTUNE observatory supports instruments at two gas hydrate sites on the continental margin off Vancouver Island, and in the hydrothermal vent fields of the Endeavour segment of the Juan de Fuca Ridge. The primary focus of the gas hydrate field observations is to understand the dynamics of the growth and stability of outcropping and sub-seafloor hydrate deposits. Outcropping hydrates at 840 m depth in Barkley Canyon have been monitored for the past 3 years with a mobile instrument platform known as Wally, which is operated over the Internet by a research group in Germany. This tracked vehicle carries standard oceanographic sensors, acoustic current metres, cameras and methane sensors. Data indicate a relationship between degassing of hydrates and tidal currents. In 2012-2013 two high-resolution sonar towers were added to the hydrate field to provide precision tracking of Wally and to monitor volume changes in the outcropping hydrate mounds. A large subsurface hydrate deposit occurs at the Clayoquot Slope site, where bottom depth is 1260 metres. Monitoring instrumentation is currently being established at this location. Gas bubble release from this deposit is being monitored by a sector scanning sonar mounted on a

Sep 14, 2011

By C. Gordon Saunders

"The ungraded-fibre mill is located at the mine site and has a rated capacity of 6,600 tons of ore input and 1,200 tons of ung1•aded fib1 •e product per day. Power for operation is obtained from a diesel generating plant located on the site, which has a capacity of 5,300 kW. The preliminary milling process consists of prima1•y and secondary crushing, drying and temporary storage of plus-1 1h -in. material. The final milling processes are two stages of crushing and three stages of screening, with air-lift separation of the fibre from the host rock. The central mill building also houses a machine shop, mill maintenance shops, a mobile equipment overhaul shop, an engine and majo1•-component overhaul shop, and a warehouse. Major changes to the milling ci1•cuits since start-up have been the addition of a larger secondary cone crusher, ct third dryer, adding a rotary distributor to the feed of the screening section and adding an automatic start-up sequence for all equipment except crushers and fans. The operation of the mill is coordinated from a central control room, where a ""mimic"" panel indicates the operation of all major units in both the ore preparation and the screening sections. Product quality is controlled by continuous sampling and frequent labo1•atory analysis, which provide data fm• the adjustment of aspirating hoods and mill feed rate. Operating problems unique to this location, and common to a sub-arctic environment, are discussed."

Jan 1, 1976

By M T. Nguyen, S Vink, M Ziemski

On any given mine site the water system is contingent upon its initial design. Through time the initial design is adjusted by a myriad of water management options in order to improve water system performance or to adapt to a new production capacity or method at the mine site. These options generally do not comprehensively consider energy requirements, so it is unlikely that any given mine water system will be optimised in terms of both water and energy uses. Thus this may simply shift constraints of efficiency of one resource dimension, water, to another, energy. As a result, changes in water systems would cause more energy-related issues to mining companies. For example, the companies would have an increase in operational cost and/or pay more for carbon tax with changes in their water system. Therefore, in order to avoid undesirable and potential unforseen energy and infrastructure issues in a mine life cycle, it is essential to select suitable water management options for a mine considering both water and energy resources simultaneously.Considering water and energy criteria in evaluating water management options consists of net water volume availability, net operational energy demand and net water replacement energy demand. Ideal water management options should be high in water volume availability but low in both operational energy demand and water replacement energy demand. A water option would also be favourable if it has low potential of causing adverse environmental impacts such as lowering groundwater tables due to groundwater withdrawal, or elevating saline constituents in surface waters when reusing brine for dust suppression. However, these environmental impacts are not considered in this analysis.This article presents a graphical method to assess mine water management options, based on these three criteria. The proposed method to assist in screening mine water management options includes two main steps:1. categorise water management options into prioritised groups2. rank the options within each prioritised group.The method is applied to a gold mine and presented in this article as a worked example. CITATION:Nguyen, M T, Vink, S and Ziemski, M, 2013. Selection of mine water management options considering both water and energy impacts, in Proceedings Water in Mining 2013 , pp 29-34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By B J. Beven, A Harris, L Balzan

Fortescue Metals Group flagship operation, Cloudbreak, is located in the Pilbara region of Western Australia. The mine is capable of delivering an annualised production rate of 40 Mt/a. Positioned 50 km to the east of Cloudbreak is Fortescue’s Christmas Creek operation, which has a combined processing capacity in excess of 50 Mt/a. Following on from these successes, Fortescue advanced development of its western Pilbara mines at the 60 Mt/a Solomon Hub. These processing installations place Fortescue in a strong position to deliver on a guidance of between 155–160 Mt/a for financial year 2014/2015.As Fortescue enters a phase of asset consolidation and debt repayment over expansion, the business is commanding stronger performance through enhanced plant operating practices and mine site cost reduction initiatives. To this end, the strategic placement of instrumentation is an area being given greater consideration. Access to real-time information pertaining to conveyed materials is of major interest to operators for making timely process control decisions. Fortescue has recognised the importance of accurate and up-to-date process information about their ores and hence, has adopted the use of Scantech’s Geoscan mineral analysers at two of their mines.There are two Geoscans at Cloudbreak; one on the ROM feed conveyor and another on the final product conveyor. These allow the in-feed material grade characteristics to be assessed. Moreover, the final product stream can be monitored to ensure product quality is maintained within acceptable quality tolerances. A third Geoscan is installed at Christmas Creek mine on a conveyor that transfers final products to Stockyards.This paper discusses the use of the Geoscans in these installations, including benefits to Fortescue’s operations, as well as functional considerations such as the impact of maintenance and calibration. A discussion of recent advances by Scantech is provided including enhancements to the calibration process and minimising plant downtime, along with a summary of results obtained.CITATION:Balzan, L, Beven, B J and Harris, A, 2015. Geoscan online analyser use for process control at Fortescue Metals Group sites in Western Australia, in Proceedings Iron Ore 2015, pp 99–106 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Meredith Scaggs, Emily Sarver, Lucas Rojas Mendoza

"Early on Jan. 9, 2014, approximately 37,800 L (10,000 gal) of crude 4-methylcyclohexanemethanol (MCHM) leaked from a storage tank sitting on the bank of the Elk River near Charleston, WV (WVDEP, 2014; CSB, 2014). MCHM is a chemical commonly used in preparation of fine coal and is considered nonhazardous in terms of transportation, storage regulations and also toxicity (CDC, 2014a). Freedom Industries Inc., a producer and vendor of specialty chemical products, had acquired the storage facility from Etowah River Terminal, LLC just a few weeks prior in December 2013 (WVDEP, 2014; Freedom, 2005). The direct cause of the spill was ultimately determined to be two small holes in the base of the 76-year-old tank, which were created due to corrosion damage (Bauerlein and McWhirter, 2014).The spill site was located a little more than 1.6 km (1 mile) upstream from the intake of a municipal water treatment facility operated by West Virginia American Water (WVAW), which serves a population of 300,000 across nine counties in central West Virginia (CDC, 2014a). In a matter of hours, the leaked MCHM made its way through the treatment facility and into the water of nearby homes and businesses, where its strong smell was noticed almost immediately. On the evening of the spill, WVAW concluded that its conventional treatment processes, which include carbon filters to remove a variety of contaminants from water, were not capable of fully removing the MCHM and a "Do Not Use" order was issued for all customers (WVAW, 2014a).With little information readily available regarding the potential human health effects of MCHM, the U.S. Centers for Disease Control and Prevention (CDC) quickly issued an advisory ruling that set a maximum screening level of 1 ppm for safe drinking water (CDC, 2014a). Based on this recommendation, the "Do Not Use" order remained in effect for a total of eight days, until Jan. 17, when the WVAW distribution water was confirmed to have MCHM concentrations below the approved level (WVAW, 2014a). However, due to the pungent odor of the chemical, its presence was still recognizable in the WVAW facility and in consumers’ tap water after the order was lifted (Manuel, 2014). Recent studies have shown that the chemical can be detected in water at sub-ppb concentrations, a fact that undoubtedly added to growing public concern (Rosen et al., 2014; Gallagher et al., 2014). In response to numerous complaints and demands, WVAW continued flushing the treatment facility and pipes until Feb. 25 when MCHM levels were measured below 2 ppb (WVAW, 2014b), and eventually replaced the affected filter media (WVAW, 2014c)."

Jan 1, 2014

Jan 1, 2001

By Michael Murphy, Khaled M. Mohamed, Berk Tulu

"Failures of coal ribs are major hazards in underground coal mines. For the period of 2010 to 2014, rib falls were the leading cause of groundfall fatalities and accounted for 35% of all groundfall-related fatalities. Currently, the National Institute for Occupational Safety and Health (NIOSH) is conducting a research project to develop an engineering-based design methodology for rib control in underground coal mines to reduce rib fall accidents and fatalities. Numerical models can be used as part of the design methodology provided the models are appropriately calibrated and verified.This paper presents a coal rib model to simulate the mechanism of coal deformation and fracturing that can lead to stress-driven rib falls. The proposed coal rib model was calibrated against published data from an instrumented rib site at the West Cliff Mine in Australia. Fracturing of the coal rib was defined by critical VALUES (of plastic shear strain of the coal material and rib displacement. A critical plastic shear strain of 2.8% and a sudden increase of rib displacement of 30 to 45 mm were sufficient to develop a fracture plane in the rib model. Accordingly, a discontinuous rib deformation was achieved and it compared favorably against field monitoring data.INTRODUCTIONCoal ribs are the vertical walls of coal formed when entries are developed in a coal bed. Failures of coal ribs are a major hazard in underground coal mines. Furthermore, failing ribs can contribute indirectly to roof and floor instability by increasing opening widths across intersections and entryways. Over the last 18 years, there has been a continual occurrence of injuries and fatalities in underground coal mines due to rib falls. For the period of 2010 to 2014, rib falls (excluding longwall face failure and bursts) were the leading cause of ground fall fatalities and accounted for 35% of all groundfall-related fatalities (MSHA, 2015)."

Jan 1, 2016

By Joseph A. Meyers

NYC has always been a high-profile target for both foreign and domestic terrorists. Explosives have always been the go-to tool for terrorists to bring about serious physical injury, death, and property damage in our society. Today with the anti-police movement gaining traction in the United States and anarchists groups using homemade explosives against law enforcement and municipalities, it is the responsibility of the explosives industry to ensure that every explosive product on a blasting site is secure. We must prevent the theft of these energetic materials used on projects and sold by vendors so they are not used by these terrorists. We have learned many lessons here in NYC which began with the theft of explosives used for blasting projects in NYC to supply the IRA (Irish Republican Army) 50 years ago. The liability is too significant to take short cuts in securing energetic materials. Over the years through cooperation with all agencies and the industry we in NYC have developed certain proven protocol and procedures we would like to share with the industry. An efficient and effective security plan for the logistic movement of explosives, as well as for the blast site is imperative to keeping the good name of the industry from negative repercussions and possible additional bureaucratic oversight of an industry that is highly regulated and still recovering from the pandemic. Communication, security assessments and transparency with all stakeholders and the Authority Having Jurisdiction (AHJ) will greatly improve the overall security for the blasting project. This SOP (standard operating procedure) will allow the AHJ to become a proactive partner in the security of the blasting project. If the AHJ is not a law enforcement agency, the law enforcement agency specialty unit must be notified and included in all phases of the project. The security for a blasting project with AHJ and law enforcement input starts at the inception of the project when the memorandum of understanding (MOU) is obtained, and involves the AHJ through all steps of the approval process. This includes threat assessments on new and existing structures. SME’s (Subject Matter Experts) must be present at all stages. The blasting industry and regulators must work collaboratively to improve safety, security, and create a dialogue with law enforcement and the AHJ. Relationships are built through trust, teamwork, transparency, and communication and greatly improve the safety of our great country.

Jan 21, 2025

By M Pomery

BHP’s Western Australian Iron Ore Operations (WAIO) move approximately 250 million tons of ore per annum. The magnitude of the constant changes to the terrain models along with the diverse output and presentation requirements of numerous stakeholders presents significant challenges for the geospatial team. This paper describes how the WAIO Survey team use a combination of technology and optimised workflows to capture, ingest, publish and access large data sets for diverse stakeholder requirements. Machine learning for processing of data and the use of web based systems to track and prioritise task allocation of resources will be discussed in detail, in addition to the changes to the traditional roles of surveyors from the use of automation and mobile technology.

Sep 18, 2023

By James Addis, Zoheir Khademian, Marcia L. Harris, Charlie Matthews, Y Zheng

Shale gas wells can sometimes drill through coal reserves. Hypothetically, the caving of the gob from longwall coal mines may deform the shale gas well casing and potentially result in a breach. NIOSH researchers studied the permeability of the surrounding ground strata that may affect the potential for an inflow of gas into an underground mine environment. An overview and comparison of measured permeability values under differing cover depths (147 m and 353 m to the Pittsburgh coal seam) and mining cycle phase will be presented and discussed in this report. The findings highlight data-driven experimental evidence that affect the interaction between gas wells extraction and mining operations that may lead to potentially hazardous environments.

Feb 1, 2025

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. It is the most widely used method/procedure in the tunnel industry. 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. This paper is based on the PhD thesis entitled “Improvements to the Current State of the Practice in Steady-State, Groundwater Inflow Estimates into Rock Tunnels based on the Application of Statistical Analysis Methods of Packer Test Data obtained from Exploratory Borings During Geotechnical Site Investigations.”

Oct 9, 2020