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By P. B. Altringer

The Bureau of Mines conducted laboratory tests to develop a process for recovering a marketable grade of tungsten from the brine of Searles Lake, Calif. The brine contains only 56 parts per million of tungsten (70 ppm WO3). Using ion exchange resins synthesized by Bureau chemists, 98 percent of the tungsten was extracted from the brine and 92 percent of the tungsten vas recovered as a marketable iron-tungsten concentrate containing 44 percent tungsten as tungsten trioxide. Although major technical problems have largely been resolved, research is progressing to escalate testing in a process investigation unit to provide more reliable data for an economic appraisal.

Jan 1, 1978

By Gordon T. Clark, Stephen H. Gleaton

This paper discusses the conceptual design of cut-and-cover tunnels currently being considered as one of the replacement options for the earthquake damaged, elevated double-deck highway and seawall built in downtown Seattle 50 years ago. The 4.8 km (3 mile) long, 6-lane improvement consists of 1.6 km (1 mile) of at-grade roadway with aerial interchanges, 1.6 km (1 mile) of large two-level cut-and-cover tunnels along the Elliott Bay waterfront, and retrofit of the 50-year old, 1.6 km (1 mile)long Battery Street tunnel and north transition to grade. Construction of deep cut-and-cover tunnels, in complex glacial geology overlain by hydraulically placed fill immediately adjacent the existing sea wall, will require extensive use of concrete diaphragm walls, ground improvement and dewatering. The potential liquefaction and lateral spreading of the fill materials in this active seismic region pose significant design challenges and risk.

Jan 1, 2003

By L. A. Garfield

Since the start of mining operations at White Pine in 1953, over 22 miles of drifts have been driven for the purpose of developing the ore body. The drifts, normally driven in multiples of three or five headings, serve as conveyor belt routes, ventilation ducts, equipment and haulage roads, and initial access to mining blocks. Development openings in the flat-lying, bedded ore body are driven in rectangular section from 16 to 32 feet wide and from 8. 5 to 16 feet high. The floor level normally coincides with the bottom limit of the chalcocite values and the roof or back is carried at the most competent stratum adjacent to the top of the ore. A development front consisting of five headings and associated crosscuts is advanced at an average rate of about 100 feet per month using conventional drill and blast techniques and equipment. The cyclic nature of the functions involved in driving the openings and the need to include them in production schedules preclude significant improvements in advance rates using current drill, blast, muck, and haul sequencing.

Jan 1, 1969

By J. J. Scott, G. H. Bennett

INTRODUCTION Friction Rock Stabilizers, commonly called Split Sets,tm* have been under development since early 1973. Five years of intensive laboratory and field testing led to their introduction to the metal mines in the United States in the fall of 1976. Actual sales started in February of 1977 and, to date, over five million units have been marketed to metal mines. The present rate of useage is near 3 1/2 million units per year which is approximately 50 per cent of all roof fixtures used in the United States metal mining industry. Mr. Richard Hoppe, Senior Editor of Engineering & Mining Journal, in an article of the February, 1979, issue, entitled "Winning the Battle Against Bad Ground", said, "In hardrock mining operations in the western U.S., particularly underground uranium mines where exceedingly difficult ground is common, no roof support system has been accepted more quickly than the Split Set friction bolt invented by Dr. James J. Scott and developed by Ingersoll-Rand Co." This paper describes how Friction Rock Stabilizers function and presents technical data to show the uniqueness of the Friction Stabilizer system. SPLIT SET STABILIZERS The Split Set System is a revolutionary development in the field of ground control. The system produces an interior reinforcement to a rock mass which: *Trade Mark of Ingersoll-Rand Co.

Jan 1, 1979

By Marco Sonnenschein

Belt conveyors for tunnelling are industry standard and key to high performance of TBM drives. Conveyors reduce traffic in the tunnel and increase safety in the tunnelling process. This paper will illustrate the state of the art of tunnel belt applications in very long and curvy tunnels like the Coxwell Bypass Tunnel Project in Toronto, Canada.

Jun 23, 2024

By Clayr Alexander

Stillwater Mining Co. (SMC) is engaged in developing, extracting, processing and refining palladium, platinum and associated metals (PGM)from the J-M Reef. This geological formation is located in Stillwater, Sweet Grass and Park counties in southern Montana. Associated byproduct metals include rhodium, gold, silver, nickel and copper. SMC’s current mining operations are near Nye, MT. The company is currently developing a second underground palladium and platinum mine, the East Boulder project, about 21 km (13 miles) west of the Nye operations. A 5,650-m (18,550-ft) tunnel is required to gain access to the ore-bearing horizon (J-M Reef).

Jan 1, 1999

By Cherie M. Tilley

The Stillwater Mining Company has acquired a Tunnel Boring Machine to expedite the mine development operations at its Stillwater Mine. The machine purchased by Stillwater was previously owned by Melbourne Metropolitan Board of Works, Melbourne, Australia. The machine was manufactured by Robbins Co. of Kent, Washington. The Stillwater Mine has an extensive system of footwall laterals which are required by the mine development scheme. The initial mine plan called for in excess of 30,500 linear meters (100,000 linear feet) of footwall lateral drifts at a cross section of approximately 3.0 meters in width by 3.75 meters in height (10 feet x 12 feet). A Tunnel Boring Machine was selected for this work. The Robbins machine number is 146-193. This machine is approximately 4 meters (13 feet 5 inches) in diameter. The machine was modified extensively prior to commencing operation at the Stillwater Mine.

Jan 1, 1989

By M. Grun, A. C. Marlowe, I. Littleford

SYNOPSIS A Wirth tunnel borer owned by Anglo American Corporation completed a 1150m long tunnel some years ago and was subsequently extensively modified by Technical Development Services. In 1982 this borer provided new and particularly interesting information In the field of hard rock boring. The abrasive quartzltes traversed proved to be a challenge to the cutter manufacturer and the project team. This paper examines the problems faced, the solutions found and the lessons learnt.

Jan 1, 1983

By Rock M. Poulin, Bruce G. Moulton, Daniel E. Nowak, David T. Cass

The Yacambu Irrigation Tunnel Project of 34 km, 5 meter diameter circular and horseshoe section, has been under construction since the early 1970's. Notable among the excavation challenges is high ground cover of 3,000m creating large lithostatic pressures in the tunnel alignment with subsequent plastic flow of the ground in the tunnel walls. The tunnel may converge from small amounts to 1 or more meters of diameter over long sections. Several excavation techniques have been attempted but all without desired results. The paper proposes a new machine concept that uses the history of ground experience as its basis for design.

Jan 1, 1995

By Martin Herrenknecht

Tunnel boring machine (TBM) development continues to take on not only larger diameters, but also more difficult ground conditions. Ground conditions consisting of unstable faces with water pressures up to 15 bar have required innovative design approaches. A systems approach has been required to produce tunneling machines that can safely excavate the tunnel in an efficient, cost-effective manner that stresses production and labor saving approaches. This article reviews the current design developments and present recent projects where these most recent principles have been applied. The world?s growing population and rapidly proceeding urbanization are boosting an enormous demand for new and high-capacity infrastructures to secure the mobility of goods and people. Densely populated areas face the challenge of providing efficient traffic infrastructure such as a modern public transport system. At the same time, the maintenance and modernization of supply and disposal structures for water, sewage, energy and communication are essential. Last but not least, are supra-regional transportation routes such as long distance water diversion schemes. All of these projects are as demanding and are characterized by a tight time schedule. In this context, the demand for efficient tunnels for traffic and utility lines is increasing, as new infrastructures often leads underground because of limited space above ground. Also, tunnels are the obvious choice to cross natural barriers like mountain ranges. To handle the complex and variable geological conditions and other constraints, such as low overburden, high water pressure or long tunnel drives while facing increasing demand of a quick completion of a project, mechanized tunneling sets standards regarding safety, profitability and environmental protection in traffic tunneling projects as well as in the trenchless construction of utility tunnels. Different machine types and working principles have been developed to master various geological and hydrogeological requirements. Continuous activity in research and development leads to constant improvement of the mechanized tunneling process.

Jan 1, 2008

By Martin Herrenknecht

Tunnel boring machines continue to develop to take on not only larger and larger diameters but also more difficult ground conditions. Ground conditions consisting of unstable faces with water pressures up to 15 bar has required innovative design approaches. A systems approach has been required to produce tunnelling machines that can not only safely excavate the tunnel but do so in an efficient, cost effective manner that stresses production and labor saving approaches. This paper will review the current design developments and present recent projects where these most recent principles have been applied.

Jan 1, 2008

By Philip U. Santacroce, James H. Meinholz

One-half of the $607 million Conveyance construction portion of the Milwaukee Metropolitan Sewerage District's Water Pollution Abatement Program is completed or under contract. 12,200 m (7.5 miles) of tunnel boring machine (TBM) driven rock tunnel from 2.5 m (8.0 ft) to 9.9 m (32.3 ft) diameter has been completed. This paper presents a review of TBM performance and a discussion of the pertinent geological conditions of the area.

Jan 1, 1987

By Larry Snyder, Levent Ozdemir, Charles Fishman, Fun-Den Wang

Tunnel Boring Machine Instrumentation A 9.17 m. diameter tunnel boring machine presently in operation in Chicago, Illinois, has been instrumented to continuously monitor and record machine thrust, torque and penetration rate during boring. A micro-processor-based data logger capable of monitoring up to 60 channels of data digitizes and converts into appropriate engineering units the signals from various transducers mounted on the machine. The output from the data logger is sent to a teleprinter, providing a permanent record of measured data. The program control enables the data logger to scan all data channels at desired time intervals. Data obtained to date have been analyzed to determine the interrelationships of the parameters measured. Penetration rate was found to increase linearly with machine thrust with a unit increase in thrust causing more than a unit increase in penetration rate. For low thrust levels corresponding to the initial stages of a boring cycle, the penetration rate was observed to behave erratically until the thrust pressure was sufficiently high for the cutters to establish full contact with the tunnel face. Torque showed a curvilinear increase with machine thrust, reaching the design rating at about 70% of maximum available thrust. No-load torque was approximately 20% of the machine's rated torque capacity. Overall, the trends observed in measured machine parameters correlated closely with those predicted from experimental and theoretical boreability studies. In summary, the instrumentation system has mett two basic goals. First, it provided extensive and accurate boring data and secondly, it has proven that an automatic data acquisition system can be installed on a TBM and can function under adverse environment.

Jan 1, 1979

On Dec. 20, 2013, an 8-m (26.2-ft) diameter Robbins hybrid single shield/earth pressure balance tunnel boring machine (EPB TBM) was launched to bore the Grosvenor decline tunnel for Australia?s Anglo American coal mine. The machine was built using onsite first time assembly (OFTA) in order to fit within a tight project schedule. Assembly at the remote jobsite near Moranbah, Australia took about four-and-a-half months, and then the machine was walked down into a launch tunnel. Two decline tunnels, at grades of 1:6 and 1:8, will be used for mine access to new coal seams. The hybrid machine is tackling mixed ground conditions ranging from sand and clay to varying types of sedimentary hard rock up to 120 MPa UCS, as well as coal seams. Methane gas is expected to be present throughout the tunnel, so the machine has been designed as explosion-proof-compliant to ERZ-1. ?Grosvenor is the first underground coal mine in Queensland to use a TBM for drift construction,? said Glenn Tonkin, Grosvenor project director. ?We are proud to be pioneering this technology.? Only about 300 m (984 ft) of ground in each decline tunnel is expected to require EPB mode, while the rest of the tunnel will be bored in hard rock mode. Thus, the design was optimized toward hard rock excavation.

By Ian McFeat-Smith, Odd G. Askilsrud

Introduction Given the mountainous nature of the local igneous terrain, hard rock tunnelling plays an important role in the development of Hong Kong's infrastructure. In 1990, tenderers for two tunnel projects were encouraged to consider using hard rock TBMs, the territories' first. As a result the 7.5km long, 3.56m diameter Tolo Effluent Tunnel and the 5.3km long, 4.8m diameter Hong Kong Electric Cable Tunnel were excavated by hard rock TBMs. The successful completion of both projects in 1992 should make the TBM method an attractive construction alternative for planned, upcoming projects in Hong Kong. Tunnelling Conditions Tunnelling solutions are frequently adopted in Hong Kong due to the intensity of development, lack of flat landscape and proximity of mountainous terrain to the main centers of population. This is carried out primarily in granites or granitic-type rocks which surround Victoria harbour, and to a lesser extent in the outlying volcanic rocks which include extremely hard tuffs and lavas. Tunnelling will generally take place in granitic rocks, normally about 100-250 MPa in strength, and with an average joint spacing of 0.3m and a quartz content of 30-

Jan 1, 1993

By H. Dr. Boldt, J. Dr. Henneke

PREFACE In German coal mines the application of tunnel boring machines has become a very effective and economic technique for major development works. After initial trials around 1970 the breakthrough was reached by driving 13 km of road ways on Rheinland and Friedrich Heinrich collieries, using a DEMAG tunnel boring machine of 6 m diameter. INTRODUCTION The coal mines of Rheinland and Friedrich Heinrich are to be found in the West of the Ruhr Area, the largest coal mining area in the Federal Republic of Germany (Table 1). They form part of the Ruhrkohle company. Rheinland coal mines produces 41000 to 43000 t of run-of-mine coal every day, of which 20500 t are usable coal. Friedrich Heinrich has a daily production of 17000 t of run-of-mine coal, 9000 t of which are usable. The coal is worked at depths of 600 to 1100 m in seams 0.6 to 3.0 m thick. The method of mining is longwall, and the machines used are ploughs and shearer loaders. From 1973 to 1980 a programme was put into operation in these two mines to develop and open up the coal field on the 885 m level. A total tunnel length of 20 km was to be driven. After thorough investigations it was decided to employ a full-face tunnel boring machine for

Jan 1, 1981

By W. Setzepfandt, J. Henneke

PREFACE Debris disposal can very often be a severe problem and major restriction on tunnel boring projects, especially for small diameter tunnels and in underground mines. Hydraulic transport could provide a suitable solution. Investigations have therefore been made in connection with a full-scale project of 4.8 km length and 2,3 m diameter, to obtain the required technical and economical data for planning an optimized transport system, e.g. for a tunnel boring drivage of 6 - 7 m diameter in underground coal mines. INTRODUCTION The Radau-Tunnel, chosen for the investigations, has been designed for transferring flood peaks between the rivers Radau and Grosse Romke in the Harz-Mountain of Lower Saxony. A DEMAG TVM 20/23 H tunnel boring machine was used to drive the tunnel on a rising gradient of 0,53 %. The rock consisted of shale and hornblende (55 %), granite (15 %), diabase (15 %), chert (8 %) and gabbro (7 %). The project has been sponsored by the Federal Ministry of Research and Technology.

Jan 1, 1981

By Ali Hafiz, Aidin Golrokh, Tom Iseley, Kaz Tabrizi, Saleh Behbahani

In the USA many highway tunnels were built during the 1930s through 1960s. This indicates that these tunnels have exceeded their intended design service life. Based on the initial tunnel inventory conducted jointly by the Federal Highway Administration (FHWA) and the Federal Transit Administration (FTA), more than 526 highway tunnels have been identified in the USA. For understanding the condition of the tunnels and risks associated with deteriorating conditions, comprehensive condition assessments are necessary to mitigate risk and remediate works as required. Monitoring the condition and rate of deterioration of tunnels is vital for timely tunnel maintenance and rehabilitation to avoid sudden tunnel collapse. This session will explain the necessary steps for tunnel inspection and review some of the state of the practice information on tunnel inspection techniques.

Jun 13, 2023

By Jorge Martinez

The Muck Valley Hydroelectric Project in Northeastern California required construction of a 3.65 meter tunnel through 6,623 meters of mixed volcanic flow deposits within a critical time frame. As Engineer and Construction Manager for the Project, Morrison-Knudsen Engineers invited bids for both Drill and Blast as well as Tunnel Boring Machine methods, selecting a contractor proposing a TBM designed and built specifically for this project which could excavate a wide variety of materials and maintain acceptable progress rates to complete the work within schedule. Tunnel lining as required included shotcrete with metal fibers and full circle concrete.

Jan 1, 1989

By Luiz Roberto Amaral, Peter Frobenius

Construction of the first phase of the Sao Paulo Metro, the North-South Line, will be completed late in 1974. The downtown section of this line consists of 2.2 miles of 19.6-foot diameter soft ground tunnels and 3 subway stations. The entire tunnel - station package was let to one contractor. A plan and profile of the tunnels and stations is shown on Figure 1. Passage of the tunnels under Boa Vista Street in the Sao Paulo Financial District was one of the major challenges. The street is only 50 feet wide from building line to building line and flanked by 10 to 20 story buildings. The tunnels pass within 4 feet of adjacent footings. Further south, the tunnels run 13 feet below the flat foundations of the Caixa Economica, a massive 11 to 14 story building. Surface settlement had to he limited to less than .07 feet/tunnel and good face control and grouting procedures were essential. For this reason, full face cutting wheel tunneling machines were selected to drive the tunnels south of the Access Shaft Prestes Maia which included Boa Vista Street and the Caixa Economica. The tunnels north of the Access Shaft Prestes Maia were driven under a fairly wide Avenue and greater settlements were permitted. Open face shields were selected to drive these tunnels. Most of the work has now been completed and analyzed. Here are some of the results - Careful planning and execution of tunneling procedures kept surface settlement over the tunnels below a magnitude of .05 feet, allowing tunneling adjacent

Jan 1, 1974