Geology of the Harold D. Roberts Tunnel, Colorado: Station 468+49 to East Portal

Warner, Lawrence; Robinson, Charles Sherwood

doi:10.1130/0016-7606(1967)78[87:gothdr]2.0.co;2

Cited by 8 publications

(10 citation statements)

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“…The foliation of the granite is considered to be the result of flow. The direction of flow was controlled in part by the attitude of the foliation of the metasedimentary rocks, as indicated by their general parallelism in this area and in other areas in the Front Range (Warner and Robinson, 1967), but local deviation from the regional foliation is typical in the granite. The strike of the foliation at the surface is more closely parallel to that in the pilot bore than is the dip.…”

Section: Granitementioning

confidence: 88%

“…Rock type was found to be not as important in the construction of this tunnel as were other factors, such as the number of fractures per foot of tunnel, attitude of bedding, foliation, and fractures in relation to the trend of the tunnel, presence or absence of hydrothermal alteration, and the type of clay minerals, as the result of alteration, in fault gouge. Some of the results of the study of the Roberts Tunnel are published: Wahlstrom, Warner, and Robinson (1961), Wahlstrom (1962Wahlstrom ( , 1964, Wahlstrom and Hornback (1962), Wahlstrom, Robinson, and Nichols (1968), and Warner and Robinson (1967). The study of the Roberts Tunnel led to the conclusion that a statistical compilation of geologic features such as the distribution of rock types and the attitude of the bedding, foliation, faults, and joints could be projected to a tunnel level more accurately than could individual features and would give a better basis for engineering design and construction.…”

Section: Purpose Of Geologic Investigationsmentioning

confidence: 99%

“…Engineering geologic studies of the Roberts Tunnel (Wahlstrom and Hornback, 1962;Warner and Robinson, 1967;Wahlstrom, Warner, and Robinson, unpub. data) have shown that rock fractures, regardless of origin, are probably the most important geologic influence on the driving and support of tunnels in the Front Range area of Colorado.…”

Section: Surface and Underground Geologic Studiesmentioning

confidence: 99%

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Engineering geologic, geophysical, hydrologic, and rock-mechanics investigations of the Straight Creek Tunnel site and pilot bore, Colorado

Robinson¹,

Lee²,

Scott³

et al. 1974

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Tunnels are among the most expensive of engineering structures. They can, and often do, present great difficulties in design and construction. For several decades the techniques used in tunneling have lagged behind those used in other fields of engineering. An engineer, for example, can design a bridge so that it will adequately and economically fulfill its proper function. The design and construction of underground openings commonly is a far different situation. The stresses surrounding a planned underground opening are generally unknown quantities, as are the nature and behavior of the rock mass itself. Therefore, judgment and trial and error prevail; design, in its true sense, becomes impossible; and safety factors can be uneconomically large or dangerously small. Geological factors exert a decisive influence on the difficulties and costs of tunnel construction. Tunnel hazards unanticipated sources of expense and delay are caused largely by the divergence of structural details of a given rock mass from the statistical average for similar rock masses. This variation in rock structure results in erratic tunneling costs; the cost of a tunnel may be considerably higher than the average cost of similar tunnels constructed in similar bodies of rock. A competent experienced geologist usually can predict the kinds of difficulties that would be encountered in different parts of a proposed tunnel, but he seldom can quantitatively evaluate the difficulties. On such a basis, preliminary estimates for materials and equipment for constructing a tunnel commonly involve considerable guesswork. This guesswork usually results in the procurement of unnecessary supplies to offset the possibility effacing an emergency with inadequate provisions. The present (1972) state of tunnel art combines experience and intuition with theoretical and practical principles to design and construct underground openings. We believe that in the future the fullest use of rock-mass information, together with improved theory, will result in greater economy, safety, and confidence in tunnel construction. It is toward this goal that the present report is directed. The Straight Creek Tunnel is about 55 miles west of Denver. The proximity of this tunnel to the research center of the U.S. Geological Survey in Denver offered an unusual opportunity to utilize the personnel and facilities of the Survey on the problems of defining the environment of the proposed tunnel. The authors were able to consult with, and have the services of, experts in nearly every field of geology. As a result, research investigations in the tunnel area were conducted by many survey personnel. The investigations performed in conjunction with the basic geologic investigations, such as geophysical and groundwater research, are described in separate chapters by those who directed the research. At the dedication of the first of the twin bores on March 8, 1973, the Colorado Division of Highways, in accordance with a resolution passed by the General Assembly of Colorado, officially named th...

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Section: Granitementioning

confidence: 88%

Section: Purpose Of Geologic Investigationsmentioning

confidence: 99%

Section: Surface and Underground Geologic Studiesmentioning

confidence: 99%

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Engineering geologic, geophysical, hydrologic, and rock-mechanics investigations of the Straight Creek Tunnel site and pilot bore, Colorado

Robinson¹,

Lee²,

Scott³

et al. 1974

Professional Paper

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“…The stock and its associated ore deposits are described by Lovering and Goddard (1950) and Neuerburg and others (1974). Excellent descriptions of the main stock, where it is penetrated by the northwest-trending Harold D. Roberts water tunnel are given by Wahlstrom and Hornbeck (1962) and Warner and Robinson (1967). Simmons and Hedge (1978) report a Rb-Sr date on biotite of 39 Ma for the Montezuma stock.…”

Section: Montezuma Stockmentioning

confidence: 99%

Ages of selected intrusive rocks and associated ore deposits in the Colorado mineral belt

Cunningham¹,

Naeser²,

Marvin³

et al. 1994

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“…The relation of the geology of this interval of the Roberts Tunnel to the regional geology of the Front Range is discussed in Chapter B. A discussion of the Precambrian geology, with a more detailed discussion of the genesis of Precambrian rock types has previously been published (Warner and Robinson, 1967).…”

Section: General Geology From Station 690+00 To the East Portalmentioning

confidence: 99%

Geology of the eastern part of the Harold D. Roberts Tunnel, Colorado (Stations 690+00 to 1238+58)

Warner¹,

Robinson²

1981

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Geology of the Harold D. Roberts Tunnel, Colorado: Station 468+49 to East Portal

Cited by 8 publications

References 0 publications

Engineering geologic, geophysical, hydrologic, and rock-mechanics investigations of the Straight Creek Tunnel site and pilot bore, Colorado

Engineering geologic, geophysical, hydrologic, and rock-mechanics investigations of the Straight Creek Tunnel site and pilot bore, Colorado

Ages of selected intrusive rocks and associated ore deposits in the Colorado mineral belt

Geology of the eastern part of the Harold D. Roberts Tunnel, Colorado (Stations 690+00 to 1238+58)

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