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By Gerald Zink

The object of underground excavation--apart from mining-- is to create an opening to serve as a part of some useful structure. The value of the opening lies in its conformity to the design configuration and its stability during the planned life of the structure. The wire saw could be used to excavate openings of high value at a cost competitive with present methods. First, a discussion of present methods will be used to explain where wire sawing fits in and how it should be applied. PRESENT EXCAVATION METHODS Tunnel Boring A recent advance in tunneling technology is the use of mechanical boring machines. There are many ways that a boring machine can reduce the cost of a tunnel or increase its value. I will mention a few of the advantages that have been demonstrated in tunneling projects. A tunnel can be bored without overbreak, allowing concrete lining to be poured to the design thickness without waste. Boring creates a minimum of disturbance to the tunnel wall, preserving the natural strength of the rock and reducing the amount of support which must be installed to maintain stability. A boring machine maintains the tunnel at its full dimensions and proper shape, and it leaves no rock projecting from the wall which must be trimmed off. The use of boring machines is presently limited to openings of uniform cross section and great length. If the previously mentioned attributes of mechanical boring could be applied to excavation of a wide variety of chambers and passages, then a corresponding decrease in cost and gain in value would be possible for chambers.

Jan 1, 1974

By Ben E. Lusk

First of all let me say what a genuine pleasure it is to be here. Acapulco certainly is a beautiful change. I'm going to spend sometime talking about change, because frankly I'm astounded at the rate of change in our world today. One good example of this, reminds me that the first time I spoke before the AIME two years ago, we were at the Ramada Inn in Beckley, West Virginia. Today we're at the Princess Hotel in Acapulco, Mexico. Now that's what I call a change. Seriously though, I'm sure you've all heard it said that the most consistent thing about our society is its constant change. Five years ago, no one could have predicted the changes we experienced in the United States during the first half of the 1970's. In the past twenty-four months alone, we have seen two presidents, three vice-presidents and hundreds of administration and government personnel changes. We have stumbled from one social crisis to another, while suffering through rising inflation, major energy shortages and labor unrest that could plunge us into a full scale economic depression. In view of these constant and unpredictable changes around us, it's obvious that we must learn to deal with change and "roll with the punches" if we are to survive. A controversial book published recently, explores in detail the various aspects of change and its impact on man.

Jan 1, 1974

By W. O. Henderson, H. W. Seaney

The sinking and grouting methods employed at the 3C and 3D ore hoisting shafts and the No. 5 service shaft are discussed. The reasons for selecting a circular section over a rectangular one and other technical aspects are reviewed.

Jan 1, 1974

By Jorge A. Benitez Muro

Within the exploration programs carried on by the Consejo de Recursos Naturales No Renovables, the one with the largest coverage (more than 75, 000 square kilometers) is the northern Coahuila Exploration Project. Due to its nature, geochemical exploration methods were selected to obtain quick results. The program included essentially, three main stages : 1. - A regional geochemical stream sediment survey. 2. - Semi-detailed studies of the anomalous areas selected in the previous stage, and 3. - Detailed exploration of the promising areas. To the date, the first two stages have been completed, and the third one is being carried on. The work was started on september 1972, and it will probably take one more year before drilling can be started, but at the end of stage three it is expected that at least 5 important targets will have been detected. The regional work was conducted by 3 field crews, but the detailed program is being done by only one.

Jan 1, 1974

By Jose F. T. Agapito

The mining engineer must be able to predict the structural behavior of the rock around underground openings so that he can answer questions relating to safety and economics. With the present status of rock mechanics knowledge, exact predictions cannot be attained and approximate idealizations are made. As a first approximation, structural design makes use of theory, laboratory testing of rock properties, and available experience from excavations in similar rock formations. However, realistic design can usually be obtained only after in-situ observations and measurements are made. After all the information is collected, judgement and experience play a most important role in the final formulation of the design. This paper describes part of a geotechnical program which was instrumental in obtaining information for the design of large oil shale pillars. The work was carried out during 1971 and 1972 in the experimental mine of the Colony Development Operation. Colony is an oil shale venture formed between Atlantic Richfield Company, Operator, The Oil Shale Corporation, Cleveland-Cliffs Iron Company, and Sohio Petroleum Company to conduct research and development in mining and retorting of oil shale, The property is located in the southern edge of the Piceance Creek Basin in northwestern Colorado, approximately 250 miles west of Denver (Figure 1) . Mining was conducted by the room-and-pillar method in a 60-ft high portion of the Green River Formation at a depth of 600 to 850 ft, Pillar dimensions are approximately 60 ft by 60 ft. The mine site is in the eastern face of the canyon containing the Middle Fork of Parachute Creek, The distance from the mine to the side of the mountain varies from 500 to 1,200 ft, and its height above the stream floor is approximately 700 ft.

Jan 1, 1974

By Franklin T. Matthias

No one involved in the contruction business wants litigation, except maybe some lawyers. Contractors rarely resort to litigation unless they have sustained econmic wounds that are serious or mortal. The major cause of serious contractor losses occur because of sub-surface conditions which cannot be defined with certainty in any practicable way except as shown during construction and prove during construction to be substantially worse and more expensive to cope with than anticipated during bidding. Building, Dam and Highway contractors are generally close in their estimates of cost after they get foundations excavated and are building above ground. Their main risk in bidding is the cost of getting out of the ground compared to their estimate. So maybe 10%, 20% or even 30% of their project represent high risk underground work. The tunneling and underground contractor is dealing with high risk work for virtually 100% of his project. He appreciates this risk and is willing to assume it up to a bearable limit. His costs are highly sensitive to relatively small variations of the ground in underground work. His work is unique in other respects. As contrasted with other types of construction where loads develop as construction progresses and do not reach ultimate until the project becomes operative, tunnel and underground construction requires the immediate structural support of ultimate loads that are there when he digs or very soon thereafter. He must put in enough support

Jan 1, 1974

By Robert S. Mayo

The haulage of muck from mines was first illustrated by Georg Agricola in De Re Metallica in the year 1556. In many of his ancient wood cuts he showed a crude car running on wooden rails. These wheels had no flanges. There were four pins sticking down from the car to guide it along the rails. Eventually they made the wheels of cast iron with flanges on them. In England, coal was hauled from the pit mouth to the nearest river or canal in "wains", or wagons, running on the common highways. These wains carried one chaldron of coal, weighing 2500 lbs and it took six horses to haul these wains over the atrocious roads of that day. Somebody, about 1760, invented a cast iron rail. These were cast iron troughs, 4 ft long laid on wooden sleepers. With these iron rails they found that one horse could do the work of six. But this U-shaped groove trapped all the dirt and grit. Somebody had the brilliant idea of attaching a flange to the inside of the wheel and from then on the rails were of timber protected against wear by a strap of iron. Rolled rails, of wrought iron, were first used in England in 1820. I am sure that many of you people have wondered why the British and American railroads standardized

Jan 1, 1974

By T. O. Price

In 1969 Holosonics designed and developed a portable system for conducting acoustical surveys in metal mines, with lead-silver veins as the principal targets. Recently this system has been proven useful in describing rock structures for advance geologic information in civil engineering application and underground construction applications. This paper discusses a case history of acoustical surveying from a series of pilot drill holes in an advancing tunnel. In acoustical surveying a pulsed acoustic signal is used to generate reflected signals from the rock formation. Arrival time, amplitude and phase of the returned signals can be determined. These data became the basis for a signal correlation program designed to relate the signals to their respected pseudo-planar reflecting interfaces. An application of acoustical surveying has recently been conducted in a portion of the excavation for the Washington Metro Area Transit Subway. The data results and conclusions of the program are discussed in the paper. Acoustical surveying was successful in predicting the occurrence of major jointing and foliation plane shearing ahead of the tunnel advancement.

Jan 1, 1974

By Herbert M. Mandel

INTRODUCTION Designers of major public works projects in the past have displayed varying degrees of environmental consciousness, and tunnel designers in particular have always had to deal with certain environmental considerations - ventilation, lighting, aesthetics - as matters of primary design. Today, however, with a widening sector of the public becoming environmentally aware, tunnels are treated as elements of whole transportation systems, and are subject to increasing environmental scrutiny. The Route H-3 tunnels in Hawaii are examples of the time, care, and detail involved in a major rock tunnel project. Project Description The Route. Interstate Route H-3 is a proposed 10-mile highway crossing the Koolau Mountain Range on the island of Oahu, Hawaii, providing a direct connection between the Pearl Harbor area and the windward part of the island in the vicinity of Kaneohe. It is designed as a dual highway with provision to accommodate mass transit. As shown on Figure 1, the project includes two sets of twin bore tunnels (through the Main Koolau Range and through Red Hill), three highway sections of which two are through largely undeveloped mountain valleys (South Halawa and Moanalua), a viaduct, and three interchanges. From the Halawa Interchange to the Kaneohe Interchange, the proposed highway consists of two 3-lane roadways separated by a median where the highway is at grade. One lane of each roadway will not be constructed initially but will be landscaped and reserved for mass

Jan 1, 1974

By T. D. Rourke, E. J. Cording, O&apos

INTRODUCTION Detailed investigation of a 60-ft-deep excavation in a mixed profile of sands and stiff clay was performed by the University of Illinois for the Washington Metropolitan Area Transit Authority (METRO). The work was coordinated through DeLeuw, Cather and Co., the General Engineering Consultant of METRO. Instrumentation was concentrated in a portion of braced excavation for the Gallery Place Station near the intersection of 7th and G Street. The early construction date, the 60 ft depth of cut, and the proximity of large buildings formed the basis for selection of this site as the focal point of observation and measurement. A history of lateral and vertical displacement is provided wherein movements which occurred during excavation to the full depth of cut and, subsequently, during station construction and the removal of braces are described in detail. Observations of preloading and the consequent brace loads and wall displacements are described. The effect of temperature change on brace loads is discussed and the measured apparent earth pressure for the 60-ft cut is provided. The paper discusses the relationship of lateral displacements of the cut wall to the construction procedure, and compares the lateral wall displacement with both lateral and vertical movement in the surrounding soil mass. Based on observed movement, the method by which displacement was predicted for a nearby 82-ft-deep excavation is described. The performance of the 82-ft-deep excavation has been summarized elsewhere (2).

Jan 1, 1974

By Henry R. Tiedemann, Eugene H. Skinner, George E. Wickham

Improving the state-of-the-art of tunneling is a continuing challenge to those involved in underground construction. New methods and procedures are usually evolved over a relatively long period of time as compared to advancements in other types of construction. To a large extent this is probably due to the fact that tunneling deals with a material or medium - the rock structure - whose physical properties are not only extremely varied, but in many instances virtually unknown until time of penetration. This hovering of the unknown tends to make "non believers" of many and at best leads to a general reluctancy of accepting new ideas or procedures. The situation is further complicated by: 1) discrepancies in terminology and respective meanings as used by different disciplines to describe, define or evaluate pertinent factors and their relative effect on the tunneling process and 2) the fact that no two tunneling situations are identical with respect to either geological conditions or construction and contractual requirements. In spite of the above there have been many successfully completed tunnels which make it apparent that both the technical and practical expertise needed to develop or project improvements is available within the industry. It is with this in mind that the RSR concept was developed. BACKGROUND This paper presents the findings and results obtained from contin-

Jan 1, 1974

By Paul L. Russell

U. S. petroleum demand has increased at a rate greater than that of domestic production. A domestic energy source that is under serious consideration to augment present supply is oil shale. The Green River formation in Colorado, Utah, and Wyoming represents a resource potential containing about 2 trillion bbls. of oil in shales averaging 15 gallons or more per ton or more than 400 billion bbls. in 30 gallon per ton shales. This paper will consider the technological and environmental aspects of developing this resource.

Jan 1, 1974

By A. C. Lyons, A. J. Reed

INTRODUCTION A trend which is obvious in the United Kingdom and is thought to be evident in other parts of the Western world is the disproportionate rise in the cost of tunnel mining labour compared with other tunnel cost increases. This disproportionate increase in labour costs has been accompanied by, and may be the result of, a shortage of skilled working labour. To combat this problem there has been a steady increase in the use of machines for excavation and for the erection of tunnel linings to keep the amount of skilled labour working below ground to a minimum. The typical tunnelling cycle, where the ground needs continuous support can be excavation, temporary support, temporary lining, grouting and permanent lining. It is obviously an advantage to combine as many of these operations as possible and carry out as much as possible by machine. Machines have been developed which will, either alone or used in combination with a shield, excavate and, when necessary, temporarily support the excavation. If a segmental lining is used, it can be so designed that it will form the permanent lining and reduce the cycle time and skilled labour requirement to a minimum. In cases in which the ground can be cut accurately to a smooth profile and will stand without support for a sufficient time, the lining can be expanded against the ground and the necessity of grouting eliminated. In cases in which ground will not stand without support, the usual method is to use a bolted lining and to grout behind it preferably as the shield is shoved forward. Whichever technique is used (this is largely determined by the ground) it is an advantage to make the segments as large

Jan 1, 1974

By Robert D. Talvensaari

It is indeed an honor for White Pine, as a member of the copper mining industry, to participate in this Rapid Excavation Conference. Although our presentation, as the title indicates, is not a success story, we foresee, through our experience, future application of boring machines and rapid excavation equipment in the hard rock mining industry. One might ask what a copper mining company would be doing with boring machines and why the gamble on a high-cost, capital investment for a relatively untried application. Perhaps a little background on the White Pine mine and its geology will explain our daring and speculative motives. THE WHITE PINE MINE The White Pine Copper Company, a wholly-owned subsidiary of Copper Range Company, operates a mine, mill and smelter at White Pine, Michigan in the western Upper Peninsula approximately 6 miles due south of Lake Superior. We employ approximately 3,000 people from the surrounding area and mine approximately 25,500 tons of low grade (1%) copper ore per day. The orebody is contained within several distinct sedimentary horizons that comprise the lower 20 feet of a Precambrian formation known as the Nonesuch Shale. Numerous articles and reports have described many aspects of the White Pine operation and the geology. I will brief you only on that criteria which precipitated our interest in rapid excavation equipment and techniques, specifically, boring machines. Mineralogical and optical studies have demonstrated that the siltstones, sandstone and shale beds all contain relatively barren and discrete particles of quartz (25%), feldspar and mica, bonded with

Jan 1, 1974

By L. John Minnick

Current developments in using lime and limestone slurries to remove sulfur oxide gases from the stacks of coal- and oil-burning furnaces have established an important need for treatment systems which include adequate disposal of resulting waste materials. The paper briefly outlines the classes of scrubbers which are using lime and limestone and describes the characteristics of the by-product material being produced. Some discussion is also included relating to methods of disposal of the scrubber underflow. Since coal-burning plants also produce fly ash as a waste material, one system developed by the author's company combines this material with the sulfur oxide by-products. The mixture is processed in a manner which converts the waste products into usable materials with acceptable structural and environmental properties. Recent interest in protection of ground waters from heavy-metal leachates has made the fly ash-sulfur oxide system an acceptable means of disposal, because the conversion products have very low permeability and adequately encapsulate soluble salts within the hardened mass. Although only limited information is available on the types and chemical requirements of limestone used in these processes, a few guidelines are presented to indicate the range of materials that can be used with good results.

Jan 1, 1974

By J. Donovan Jacobs

Many improvements in the art of underground excavation have appeared during the past two decades. These improvements have been both in methods and in machinery and have resulted in more economical construction of today's tunnels. In the realm of machines, the developments of continuous boring heads for either soft ground or rock, random arm excavators and the sliding tunnel floor (Magic Carpet) have each made contributions toward more rapid tunneling. CONTINUITY OF ADVANCE Tunnel boring machines are often referred to as "continuous excavators". Continuous advance (without cyclical interruptions) has not been achieved, however, in any of the machines now in use. In most rotary-head tunnelers the thrust needed to make the cutters bite into the face is obtained from hydraulic cylinders reacting against anchoring devices held stationary by pads which grip against the sides of the tunnel. With this system the forward motion of the cutting head is continuous only until the propelling cylinders have reached their limit of extension. At this point the grippers must be released, moved forward and reset before a new cycle of advance can be begun. Some machines are built to obtain their propelling thrust from hydraulic cylinders pushing backward against newly-installed rings of tunnel support. This is the customary method for propulsion of shields. With it, each cyclical advance or "shove" must await the erection of a new ring of supports. Faster tunnel driving

Jan 1, 1974

By Charles H. Jacoby

The economic importance of salt domes has been recognized throughout the world primarily because of oil and gas accumulations on their flanks and, to a lesser degree, for the value of their salt and potash. Recently they have become of value as hosts for cavities used to store hydrocarbons. In the near future we believe that their main value will be as a source of geothermal energy. Although tremendous effort has been expended on the understanding of the geology and physical characteristics of the strata intruded by salt domes, relatively little energy has been exerted in the comprehension of the salt dome itself. Salt domes have long been recognized as a geological heat anomaly. With respect to other sedimentary rocks, salt is a good conductor of heat. Expressing values in 10-3 cgs units, sedimentary rocks vary from 1.0 to 8.0; metamorphic rocks from 5.2 to 8.4 and igneous rocks from 3.1 to 9.8. Rock salt in its pure form has a thermal conductivity of 17. (Gussow, 1970). Thus a salt dome (Fig. Ml) can be expected to act as a conduit bringing heat vertically from deep within the Earth's crust. This was, in part, substantiated when in 1958 a horizontal core hole was drilled from within the Avery Island Mine at the 500 foot level. The horizontal hole was started where the ambient temperature of the salt was 74° F. and drilled toward the center of the dome. At the end of this 2,000 foot hole the temperature was 90° F. thus depicting a horizontal temperature gradient of 7° F./1,000 feet. Because this core hole penetrated a shear zone connate water that appeared as a "cold spot" on the temperature gradient, the foregoing data can only be regarded as indicative.

Jan 1, 1974

By Lorraine B. Burgin

The extensive lead time to develop most Arizona copper deposits commenced with initial production efforts before the turn of the century, when the first attempts were made to recover gold and silver and later copper from the high-grade vein deposits of the territory. Each of these discoveries, prospects, and early operations had its own lead time and life cycle as economic production was attempted. Because prices of the metals fluctuated and the higher grade material was depleted, economics forced operations to close and companies to fail. Renewed interest in the property because of improved conditions, different interpretation of the geologic structure, or new promotional ability frequently resulted in the formation of yet another company to finance the exploration and, hopefully, the development of the property. This cycle of renewed activity and subsequent abandonment was and is common, accounting for many lead times and for the long period of time from the initial location of claims to large-scale production. In order to gain a perspective on the lead-time interval necessary to achieve development of a large-scale operation, the histories of several major Arizona mines were examined, rather than a simple listing of discovery and production dates of many mines to arrive at a statistical average. The Miami, Castle Dome, Copper Cities, San Manuel, and Twin Buttes properties were studied, and as much data as possible obtained on the Pinto Valley, Esperanza, Sierrita, Pima, and Mineral Park-Ithaca Peak properties.

Jan 1, 1974

By A. A. Mathews

INTRODUCTION When Palmer King asked me to prepare a paper for this conference, it seemed quite appropriate, since I am Chairman of Subcommittee No. 4 of the U. S. National Committee on Tunneling Technology and we are presently making a detailed study of contracting practices. Before the end of this year, we expect to publish our report containing guidelines aimed at improving our contracting practices and minimizing the problems which develop therefrom. The American construction and mining industries today are glowing examples of the ingenuity of man pitting his wits against the unknown. Without the promise of rewards commensurate with the perils faced and the effort expended, it is doubtful that these industries could have reached their present state of advancement. Nevertheless, these industries are still primitive compared to many others such as aerospace and electronics. That our present contracting practices leave something to be desired is evidenced by the fact that many of our underground projects wind up with tremendous increases in estimated cost, financial disaster, and costly dispute and litigation. The situation is aggravated by the current economic uncertainty, energy crisis, and shortage of materials. At the same time, if our industries are to develop their maximum technologic potential, we must employ contracting practices which will encourage that development. Most of the contractual problems related to underground construction are associated with risk and its management. Unless all of the ramifications of this subject are understood, it will be difficult

Jan 1, 1974

By D. C. Torre

Ever since the introduction of the first successful continuous mining machines some twenty odd years ago, there has been an obvious, and steadily increasing, need for some form of continuous haulage machine, or system to work with them. There is universal agreement that the continuous mining principle, and the various continuous mining machines in particular, have done a great deal for mining. However, coal mining men, who have the longest and broadest experience with them, agree that continuous miners do not truly mine continuously. In fact, their estimates, and actual studies, show that the real mining time of these machines ranges, on the average, from 20% or less to about 30% of the available shift time. Part of the failure of the continuous mining machine to mine continuously may be ascribed to breakdowns in its intricate machinery. Most of the failure, however, is blamed on a variety of other factors. Of these, there are two which are given particular blame: face haulage and roof control. The relative importance of the two as the major negative factor in continuous mining is a moot point. However, there is an extensive concensus that haulage is the number one problem. Roof problems and their control are inhibiting factors regardless of the type of mining or mining machines employed. But the truth of the matter is that a continuous mining machine, like any type of loading machine, whether underground or on surface, is only capable of mining or producing in direct ratio to the mineable, or loadable, material that can be kept ahead of it and equally, if not more, important, that can be taken away from it. While the first commercially successful continuous miners were developed for, and proved successful in, coal mining, they were soon

Jan 1, 1974