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By Frank T. Wheby, Edward M. Cikanek

A computer performs all logic and computations customarily done by hand in preparation of engineers' estimates or contractors' bids on tunnel-shaft systems. The program described is based on construction methods, work forces and equipment selections corresponding to the current state-of-the-art of rock, soft ground and cut-and-cover tunneling. The program contains logic to permit estimates of cost of complicated tunnel-shaft systems; it is not necessary to input quantities, as the program calculates those from the tunnel design that is internally generated. In any estimate, the program bases its cost computation on user-input requirements and site conditions, such as tunnel shape and size, shaft depth, ground characteristics, construction methods, and other factors. To provide great flexibility, the user of the program is provided with options for accepting designs built into the program or overriding these designs by his own inputs. An illustrative example is presented.

Jan 1, 1974

By Claus Becker

At the RETC 1979 in Atlanta/Georgia it was reported about the beginnings of the Hydroshield system and the first site experiences. Since that time over 10 miles of tunnels in various diameters have been built with that system, and the discussion of the two most interesting projects will be the main topics of this paper. AURELIA TUNNEL, ROME In Rome, the railway system is going to be completed and modernized. Therefore, it is necessary to tunnel through the Roman hills. Part of the new railway system is the Aurelia Tunnel, located some 100 feet below the famous Via Aurelia Antigua, close to the Vatican. The double track railway tunnel has an internal diameter of 9.44 m and a length of 2.410 m. It runs through completely differing soil conditions. (Fig. 1) The first 1000 t are situated in watertight clay, the rear part in water bearing loamy, clayey sands with interlayers of loamy clays. The figure shows the soft change-over from clay to sand. The groundwater head is between [ ]

Jan 1, 1983

By G. W. Rhodes, B. P. Cavan, F. K. Mussger

The New Austrian Tunneling Method (NATM) has been successfully applied to two very different tunneling projects in the U.S.. In the case of Pittsburgh's Mt. Lebanon Tunnels, two original design alternatives were prepared. The NATM alternative incorporating a reinforced shotcrete final lining was successfully bid and constructed. At Washington Metro's (WMATA) Section B-10 Glenmont Route, Wheaton Station and tunnels, a NATM value engineering redesign was prepared for the low bidder. The design incorporating a waterproofing system based on a PVC membrane between the initial and final linings was accepted by WMATA. In both cases, European experience and standards were meshed with U.S. standard practice. Examples of NATM flexibility as an original design and as a value engineering proposal are presented.

Jan 1, 1985

By Ivano Andreis, Giovanni Valent

The Yindaruqin Irrigation Project is designed to irrigate 57,000 ha of land in the central part of Gansu Province of People's Republic of China. Water for the Project will be diverted through an 87 Km long feeder canal which will convey 36 cubic meters per second from an intake on the Datong River. (Fig. 1) The feeder canal consists of approximately 10 Km of open channels, 75 Km of tunnels and 2 Km of siphons and aqueducts. This is the biggest self-flowing irrigation water control project in the Northwest of China and it is among the most interesting projects in China for the geological and environmental conditions. Nearly half of the investment in the Project is a World Bank Loan and contractors were chosen by means of international bidding. The Italian Company, CMC Ravenna, succeeded in answering the bidding for the construction of tunnels 30A and 38, perhaps the most difficult in the Project, submitting a TBM alternative to the conforming drill and blast contract recommendation.

Jan 1, 1993

By Michael S. Kucker, Robert A. Robinson, Harvey W. Parker

Ground deformations are of major concern during tunneling, especially in downtown environments, since they have a significant impact on the costs and practicality of tunneling. This case history describes soil and groundwater conditions and ground behavior during the construction of twin transit tunnels for the Downtown Seattle Transit Project (DSTP). The tunnels were excavated through complex glacial soils ranging from hard glaciomarine drift to flowing sand. The tunneling process was greatly facilitated by the prediction of soil layer positions to an accuracy of ±0.6 m (2 ft). Tunneling was complicated by the presence of over 500 temporary tiebacks and by disturbed ground overlying an operating railroad tunnel. A variety of ground improvement techniques were used to successfully minimize settlements, which ranged from 1 cm (0.4 in.) in glaciomarine drift to 6 cm (2.4 in.) in flowing sands. Ground improvement techniques included compaction grouting, chemical grouting, jet grouting, and eductor well systems.

Jan 1, 1991

By Richard Gallagher, Russell K. McFarland

INTRODUCTION The Southern California Rapid Transit District has commenced Preliminary Engineering for an 18 mile Metro Rail Project. This initial line will consist of approximate 36 miles of single track tunnel and 16 subsurface stations. The estimated cost of $1.2 Billion in 1978 dollars, places it in the category of a major public works project. During the planning phase of this project, particular attention was paid to the National Academy of Science Reports, "Better Contracting for Underground Construction" (1974), "Better Management of Major Underground Construction Projects" (1978), and "Management of Urban Construction Programs" (1980). The improved transportation service that this project will furnish the Los Angeles Metropolitan Area will result in significant benefits that will add immensely to the economic well being of the community-which is one of Webster's definitions of improved productivity. RAPID TRANSIT PROJECT BACKGROUND Rapid Transit studies have been going c in the. Las Angeles area since 1925. In 1969 and 1974, sales tax ballot issues were not adopted by the electorate of the county mainly because the pre-ponderous of County voters are outside the City of Los Angeles.

Jan 1, 1981

By P. T. Brown

Denison Mines Limited, Canada's largest uranium producer located in Northern Ontario recently embarked upon an extensive development program that would allow them to substantially increase production and also meet the more stringent air quality standards established by the ministry of Natural Resources. To proceed with this program it was essential that the fresh air supply be greatly increased to the underground workings. A major portion of the mining area is located under Quirke Lake on the north limb of a syncline termed the Quirke Lake trough. The Denison engineers determined the most practical size and location for a proposed new fresh air shaft, eventually deciding to drive a 25 foot diameter shaft, 490 square feet in section for 1,800 feet long vertically. The shaft collar would be located on Roman Island, an island in Quirke Lake. A test hole was drilled from Roman Island to determine the ground through which the ventilation shaft would pass. This drill hole confirmed the location of the Quirke Lake over-thrust fault, a highly fractured water bearing zone 165 feet thick, approximately 800 feet below surface. Plans were made by Denison Mines Limited to seal and consolidate this ground when it was encountered by the shaft.

Jan 1, 1974

By M. K. Larson, R. G. Wade

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are studying the time- dependent response of rock stressed along weakness planes. The objective is to improve mine safety by reducing the number of roof falls that cause injuries and fatalities to miners. Researchers conducted direct- shear tests on mudstone overcored from a coal mine roof. Results showed frictional strength weakens with displacement along the shearing planes. Results of direct-shear creep tests also showed time-dependent deformation. Test measurements were compared to classical analytical models. Results suggest that the risk of roof collapse may be decreased through layout and support design to reduce creep rates and thus slow progression toward failure.

Jan 1, 2002

By Levent Ozdemir, Gerald Dollinger

An extensive series of linear and rotary cutting tests were run in soft and medium strength rocks at the Earth Mechanics Institute of the Colorado School of Mines to investigate the possibility of very high speed mechanical excavation for tunnel, raise, and shaft boring. The results of these tests demonstrate that cutter penetrations of 38.1 mm (1.5 inch) and cut spacings up to 228.6 mm (9 inch) are possible in such rock without exceeding the bearing capabilities of the cutters. It was also demonstrated in vertical boring tests that continuous excavation rates up to 38.1 m/hr (125 ft/hr) can be achieved with state-of-the-art technology provided sufficient thrust and torque is available. A predictor model for soft rocks was also developed using the test data. Analysis of this model shows that the errors between the predicted and observed cutter normal loads appear to be independent of cutter diameter, tip width, cut spacing, and depth of penetration. This suggests that the structure of the model is correct with respect to these variables. An analysis of the coefficients in the model was also made and a correlation found between the principal coefficient and Unconfined Compressive Strength. The second coefficient in the model was found to be similar in magnitude to rock properties such as Brazilian Tensile Strength, Shear Strength and Point Load Index.

Jan 1, 1989

By G. L. Dollinger, W. H. Hamilton

INTRODUCTION Design and development of new products generally proceeds through a phase of initial development and discovery based on the evolution of existing arts, followed by technical innovation and development based on both pure and applied research. The development of the mechanical tunnel boring machine (TBM) has followed a similar pattern, with the first machines closely resembling continuous coal miners. In general, however, the design of TBM's to date has been more a result of evolution and discovery than of new technical innovation, even though large sums of money have been spent on research and development. In particular, the results of experimental laboratory and field investigations have had little effect on tunnel boring machine design, and the better performance of TBM's today over those of 10 or 15 years ago, is due more to increased mechanical reliability and greater operating experience, than to improvements in penetration rates and rock fracture capability. The improvements made, have been mainly by the machine and cutter manufacturers who recognize the greater efficiency and economic advantage of utilizing large single row cutters with high load capacity along with large edge spacing. Are there any improvements to be made, therefore, in TBM performance without new and dramatic technological breakthroughs? Can TBM manufacturers design greater performance into their machines by a logical extension of the present art, and by applying what has been learned in the laboratory and field? Some, for example, believe that the kerf cutting system of boring rock is at, or close to, its opti¬mum and little improvement can be made in the present TBM concept.

Jan 1, 1979

By S. Mathur

Oxide particles are commonly used as fillers in plastics, paper, rubber, etc. (particulate composites). The successful fabrication of such composites is dependent upon the adhesive strength of the filler particles to the matrix. The compatibility of the matrix and the filler particles is generally enhanced by the adsorption of surface modifiers such as surfactants and polymers at the particle-matrix interface. To develop a scientific basis for the selection of the appropriate modifiers it is necessary to understand their adsorption mechanisms. specifically, the adsorption of polymeric additives is attributed to a combination of chemical and electrostatic interactions, hydrogen bonding and van der Waals forces. Hydrogen bonding has been suggested to be the primary adsorption mechanism for nonionic polymers. However, a literature survey of the Poly(ethylene oxide) (PEO)-oxide system suggested that PEO, a nonionic polymer, was substrate specific. A systematic study was undertaken to investigate the adsorption mechanisms of PEO on oxide particles. It was determined that strong Bronsted acid sites on the surface interact with the ether oxygen, a Lewis base, of PEO to induce adsorption. In this work, characterization of PEO binding sites on oxides is reported and the mechanisms of PEO adsorption are discussed.

Jan 1, 1999

By T. L. Brekke, T. R. Howard

Stability of an underground opening can be defined in several ways. To geologists and engineers that are used to working in geological environments where the major parts of the works after careful scaling can be left unsupported during the construction period as well as during operation, any rock mass behavior that requires reinforcement, support or lining may be regarded as a stability problem. To colleagues excavating underground openings in geological environments that require continuous use of reinforcement or support and lining "stability problems" are often associated only with those parts of the work where "standard" construction procedure and method of reinforcement or support and lining is inadequate, and special measures therefore needed. In either case, a major objective is to assess the stability problems correctly -as far as possible at the planning stage -- and choose methods for excavation and reinforcement or support that will bring the opening safely and as economical as possible through the problem areas. INTRODUCTION It is not uncommon that stability problems associated with faults or seams have been described as "unexpected." This term has unfortunately been used to indicate that no one knew that the fault or seam existed prior to excavation. A careful review of documented cases where serious stability problems have occurred revealed that the existence of these zones most often was known, but that their behavior was incorrectly assessed prior to or during construction. Miscalculations have been made in terms of the type and magnitude of loads that developed, and in particular in terms of the time-dependant behavior.

Jan 1, 1997

By Chaitanya "Teny" Mittal

INTRODUCTION A team effort by the Owner, Engineer, and Contractor can help avoid serious problems on a construction project. It can save cost and time for both Owner and Contractor, as illustrated in the following case history of the West Zone and Siouf Keblia Collector System in Alexandria, Egypt (Contract 02-AID-83/84). Under the bilateral agreement made in 1980 between the United States of America and the Arab Republic of Egypt, the United States, through the Agency of International Development (USAID), gives approximately $1 billion per year as a grant to Egypt for various development projects. The Alexandria Wastewater Management System was selected in 1981 as one such project. The Egyptian Government Agency responsible for this work is the Alexandria General Organization for Sanitary Drainage (AGOSD). A joint venture of two U.S. consulting engineering firms, CH2M HILL, Inc., and Metcalf & Eddy, Inc., called Wastewater Consultants Group, along with two local subconsultants, Engineering Consulting Group and Warith Engineering Co., were selected by AGOSD to study the sewer system and develop a plan to serve the immediate and long-range sewage disposal needs of Alexandria. Wastewater Consultants Group is currently involved in Phase I of the Master Plan. This initial step in providing Alexandria with an operating sewerage system for the current and near-term population (year 2000) consists of the design and construction management of 140 kilometers of collector and force main pipelines (including 9 miles of pipe jacking and tunneling in very soft clay), five new pumping stations, extensive rehabilitation of two treatment plants (built in the 1960s but never operated successfully), and installation of a sludge handling system. Phase I is scheduled to be completed by the end of 1991 at a total cost of around $250 million (US) plus 250 million

Jan 1, 1989

By Steven G. Vick, Herbert H. Einstein

1. INTRODUCTION The Tunnel Cost Model (TCM) is a computer based model whose objective is to quantify the risks of hard rock tunneling in terms of cost and time to completion. The main feature of the TCM is the simulation of the tunnel construction. The simulation makes it possible to incorporate in the time and cost computations the effect of uncertainties in geologic conditions and in productivity rates and costs. The cost and time computed with the TCM will be in form of distributions that allow a quantitative risk assessment. The TCM will be useful as an estimating tool permitting the estimator to rigorously relate uncertainties of individual factors to the end result. The TCM will also make it possible to evaluate technological innovations and to identify problem areas in existing technologies. The TCM consists of three interacting submodels: the geologic submodel, the construction operations submodel and the tunnel simulator. The goal of this paper is to describe the geologic submodel, whereas the construction operations submodel and the tunnel simulator will be described in the following paper by Moavenzadeh et al. First it will be shown how interactions between the geologic submodel and other parts of the TCM will impose certain requirements on the geologic submodel. These requirements, which relate primarily to the description of geologic conditions by a set of problem-oriented parameters and the quantification of uncertainty associated with geologic conditions, will then be discussed. This is followed by the description of the special structuring techniques -- decision tree and segmentation -- that are necessary to handle the great number of

Jan 1, 1974

By Heinz Kettling

Labor costs, which have rapidly increased in the industrial countries for several years, have forced the mining industry to develop new methods and cost saving systems. Also, because mining is basic to meeting the increasing requirements for raw materials, the mining industry is guaranteed a key position in cost cutting efforts. Although this report aims to describe major recent developments in the Federal Republic of Germany, it is restricted to a limited number of them in view of the wide variety of current innovations. The most important mining activities in West Germany are concentrated in the coal mines on the Rhine, Ruhr and Saar, in the lignite open-cast mines west of Cologne and in the potash and salt mining region in Lower Saxony and Hesse. This report will only discuss developments in the underground coal mines and the potash and salt mines, and focuses on projects of Salzgitter Maschinen and Anlagen AG (SMAG). HYDRAULIC DRILLS Drilling strata of varying strength One special difficulty faced in European coal mines is the varying of compressive strength of strata that occurs even over a few meters. The strata associated with the coal measures ranges from hard and tough sandstone or conglomerate to very soft carboniferous shale. It is often difficult to use continuous miners or roadheaders so that drifting by blasting still predominates. But the varying compressive strengths of the strata makes it difficult to choose the best method to drill the rock. For example, it is best to penetrate hard sandstone or conglomerate with heavy percussion drills. The soft carboniferous shale on the other hand, should be penetrated by high speed rotary drilling to obtain optimum performance.

Jan 1, 1979

By Graham A. Mathieson

A detailed breakdown of capital and operating costs is an essential element in the planning and evaluation of any mining project. The OPCOST System was developed by Golder Associates to provide mining engineers with the facility to synthesize detailed cost estimates for all aspects of an operating or potential open pit mine. The system can also be applied to underground mines equally as well. Such estimates can be prepared at a variety of levels depending on the detail required by the project. The OPCOST System is a suite of computer programs linked through a common hierarchical data base. It simulates the thought and reasoning processes within the quantity takeoff and cost estimation phases of a mining project. The system was developed as a mining cost engineering tool on the basis that it would have to satisfy a variety of purposes, namely:

Jan 1, 1982

By Thomas M. Hanna, John W. Anthony, Lee C. Atkinson

Ground water can pose major engineering and environmental problems to the new generation of large, deep gold mines currently being developed throughout the world. It is important that the potential magnitude of these problems be assessed early in the planning of such projects and that any necessary dewatering and environmental remediation programs be designed at least preliminarily in the feasibility stage. The assessment should begin with acquisition of hydrogeologic data during exploration drilling and be followed by carefully designed and analyzed aquifer tests. Once a sufficiently detailed conceptual hydrogeologic model has been defined, state-of-the-art numerical models should be used to estimate ground-water inflows to proposed pits and underground openings, to design and evaluate the potential effects of various dewatering schemes, to define specific environmental impacts, and to predict pore pressures in highwalls relative to slope stability. The modeling results will indicate which method(s) of dewatering will be most effective both technically and economically. If wells are used, it is imperative that they be as hydraulically efficient as possible. There are new methods of drilling and completing dewatering wells that can help assure maximum efficiency.

Jan 1, 1989

Crushing and grinding activity in 1989 followed the rapid pace of the mineral industry. Use of existing installations, demand for expanded capacity, and implementation of entirely new operations contributed to a high level of activity. At the 1989 SME-AIME Annual Meeting in Las Vegas, NV, the crushing and grinding session focused on wear materials in crushers and mills. Another session joined the process control group in its simulation-modeling and control of crushing and grinding circuits. Both sessions addressed the optimization in operating effectiveness. Specific subjects covered grinding media wear of forged and cast grinding balls and rubber lined mill liner wear. Also, the Semi Autogenous Grinding (SAG) Mill Conference in Vancouver in September 1989 provided a valuable update on the progress of SAG operations in recent years. Operationally, gold grinding and roasting circuits were implemented in 1989. Freeport McMoRan Gold started up two operations in Nevada. Two other circuits, both using SAG mills, are scheduled to start in 1990. These will be in Nevada and British Columbia. Elsewhere in gold, additional capacity continues to be brought onstream, both domestically and worldwide. In copper, expansions continue to call on additional crushing and grinding units. The unrest at Bougainville in Papua New Guinea has fueled a continued, strong demand for comminution in the copper sector. Specific equipment installed or started in 1989 included the ac variable frequency drive SAG mills in Australia, Alaska, and Papua New Guinea. Also, the gearless drive SAG mill in Chile provides tremendous flexibility in terms of mill speed. The trend toward moveable in-pit crushers continues -even at established operations.

Jan 1, 1990

By Kenneth K. Humphreys

INTRODUCTION At the time the 4th edition of this book was published in 1979, the coal industry had experienced a sharp upturn in prices for its product. From 1950 throgh 1969, steam coal prices had held almost flat at about $5 US per st (about $5.50/t). Thus, when considering the effects of inflation, the price of coal had actually been declining for two decades. The passage of the Coal Mine Health and Safety Act in 1969 and its cost effects started an upward trend in coal prices which was rapidly accelerated by the effects of the Mid-East oil embargo in 1972. Prices of steam coal on the spot market eventually climbed to over $30 US per st ($33/t) and higher in some cases. Metallurgical coal prices skyrocketed in a similar manner and the industry at long last appeared assured of an adequate return on investment. Many companies did expend large sums of money to upgrade and expand their mining and preparation facilities. Unfortunately the bubble eventually burst, in great measure due to the downturn in the US domestic steel industry and the resultant decline in metallurgical coal demand, loss of export markets to other nations and even imports of large amounts of foreign coal to the United States, and more stringent environmental regulations which made many high sulfur coal measures uneconomical to mine. Compounding the problem was the rapid world decline in oil prices in the mid-1980s which encouraged many consumers to utilize oil rather than coal. During the 1980s, metallurgical coal dropped over 20% in price, which, when considering inflation, actually amounted to about a 40% decrease in value. Export coal decreased a similar amount in price. Steam coal prices held nearly constant, thus also losing considerable value when inflation is considered. All of these factors make it even more imperative than ever that the industry do everything in its power to make wise economic decisions and to examine carefully all existing operations and planned future expenditures to be certain that their full cost implications are understood and that they can be justified on the basis of an adequate return on investment. It cannot be assumed that the price of coal will increase. To the contrary, as indicated previously, when considering inflation, coal decreased in value in the 1980s, just as it also did in the 1950s and 1960s. The price surges in the 1970s merely were a catchup game, and in truth the true market value of coal is in reality even lower than it was in 1950. CAPITAL AND OPERATING COST ESTIMATION Prior to constructing a new plant or expanding existing facilities, a detailed preliminary cost estimate is necessary to determine the capital investment

Jan 1, 1991

By L. R. Moore

The World Health Organization (WHO) considers contamination from oxyanions, such as selenium and arsenic, a global concern. While their elemental forms are toxic, the aqueous oxyanions are more so. These aqueous forms, which exist at a higher oxidation state, are the most common forms released during mining processes. Many technologies are capable of meeting the governmental discharge criteria for oxyanionic contaminants, but may possess limitations due to redox chemistry as well as the water matrices. An innovative technology was developed that can successfully reduce such aqueous forms generated during mining processes to a level below the discharge criteria. This paper discusses how an understanding of the sensitivities of this novel adsorbent towards these variations in water matrices and redox chemistry can be used to optimize its application.

Feb 27, 2013