Super Collider Site Research Articles

Seismic Measurements of Ground Displacements Caused by Trains and Quarry Blasts at the Superconducting Super Collider Site in Texas

Ground vibrations caused by cultural noise sources such as road traffic, trains, and quarry blasts can significantly affect sensitive scientific experiments and manufacturing processes. When constructing a facility that requires ultra-stable ground conditions it is prudent to first measure the level of background noise at the proposed site. In this study, seismic measurements are used to measure near-surface ground vibrations at the superconducting super collider (SSC) site in the state of Texas. The SSC is an oval shaped ring, which is [Formula: see text] in circumference. A design limit of the SSC is that the ground vibrations should be less than [Formula: see text] [Formula: see text] in amplitude. Seismic measurements of ground velocity were made, both at the surface and within boreholes, at several sites around the proposed SSC ring. Through a series of data processing steps the ground velocity measurements were transformed into ground displacements. Ground displacements caused by quarry blasts were sufficiently small at the SSC ring such that they posed no problem for the design and operation of the SSC. However, ground displacements caused by trains at railroad crossings significantly exceeded the displacement tolerance level of the SSC design. Furthermore, the peak amplitude in the spectra of the measured ground velocity shifted from [Formula: see text] near the railroad tracks to [Formula: see text] far from the tracks [Formula: see text]. The peak ground displacements, however, occurred at frequencies less than [Formula: see text] in both the near-field and far-field measurements. If the SSC construction had continued, it would have been necessary to either re-engineer the train tracks and railroad crossings to reduce the amount of ground vibration or to re-route the trains around the SSC ring. In August 1993, however, the United States Congress ordered the Department of Energy to halt construction on the multi-billion dollar SSC project.

Geostatistical Analysis of Fault and Joint Measurements in Austin Chalk, Superconducting Super Collider Site, Texas: ABSTRACT

Faults and joints are conduits for ground-water flow and targets for horizontal drilling in the petroleum industry. Spacing and size distribution are rarely predicted accurately by current structural models or documented adequately by conventional borehole or outcrop samples. Tunnel excavations present opportunities to measure fracture attributes in continuous subsurface exposures. These fracture measurements ran be used to improve structural models, guide interpretation of conventional borehole and outcrop data, and geostatistically quantify spatial and spacing characteristics for comparison to outcrop data or for generating distributions of fracture for numerical flow and transport modeling. Structure maps of over 9 mi of nearly continuous tunnel excavations in Austin Chalk at the Superconducting Super Collider (SSC) site in Ellis County, Texas, provide a unique database of fault and joint populations for geostatistical analysis. Observationally, small faults (<10 ft. throw) occur in clusters or swarms that have as many as 24 faults, fault swarms are as much as 2,000 ft. wide and appear to be on average 1,000 ft. apart, and joints are in swarms spaced 500 to more than 2l,000 ft. apart. Semi-variograms show varying degrees of spatial correlation. These variograms have structured sills that correlate directly to highs and lows in fracture frequencymore » observed in the tunnel. Semi-variograms generated with respect to fracture spacing and number also have structured sills, but tend to not show any near-field correlation. The distribution of fault spacing can be described with a negative exponential, which suggests a random distribution. However, there is clearly some structure and clustering in the spacing data as shown by running average and variograms, which implies that a number of different methods should be utilized to characterize fracture spacing.« less

Fault and Joint Measurements in Austin Chalk, Superconducting Super Collider Site, Texas: ABSTRACT

ABSTRACT Structure maps of 9.4 mi of nearly continuous tunnel excavations and more than 10 mi of other exposures and excavations in Austin Chalk at the Superconducting Super Collider (SSC) site in Ellis County, Texas, record normal-fault and joint populations in the subsurface within the northern segment of the Balcones Fault Zone with unmatched resolution for such a long traverse. Small faults (<10 ft throw) occur in clusters or swarms that have as many as 24 faults. Fault swarms are as much as 2,000 ft wide, and spacing between swarms ranges from 800 to 2,000 ft, averaging about 1,000 ft. Predominantly northeast-trending joints are in swarms spaced 500 to more than 21,000 ft apart.

Surface and Subsurface Features of the Late Pleistocene Beaumont Formation as Studied in a Proposed Supercollider Site in Liberty and Hardin Counties, Southeastern Texas: ABSTRACT

ABSTRACT In 1987 an area in Hardin and Liberty Counties in southeastern Texas was a much-studied candidate site for the ill-fated Superconducting Super Collider. The site is on the outcrop of the upper Pleistocene Beaumont Formation, which locally was deposited by a sequence of meandering, avulsing, suspended-load, paleo-Trinity River courses, now preserved as a well-defined to poorly defined depositional topography. Test holes in meanderbelt ridges showed that channel and point-bar silty fine to very fine sands are almost everywhere covered by approximately 10 to 40 ft (-3 to 12 m) of CH and CL overbank clays. Where completely penetrated, sand bodies are approximately 20 to 50 ft (-6 to 15 m) thick. Pedogenic calcareous deposits and slickensides at depths well below any influence from present-day surface processes are probably parts of lower horizons of truncated now-buried soils generated during the accumulation of the Beaumont, or on the surface of the underlying Lissie Formation. The relationship of one of the paleo-meanderbelts to the uplifted topographic surface of the Hull salt dome suggests that the rise of the surface postdated deposition of the Beaumont. End_of_Record - Last_Page 756-------

Style of Faults and Associated Fractures in Austin Chalk: Northern Extension of Balcones Fault Zone, Central Texas: ABSTRACT

ABSTRACT Distributions, geometries, and densities of faults and associated fractures in the Cretaceous Austin Chalk were studied in outcrop within the northernmost extension of the Balcones Fault Zone in Ellis and northern Hill Counties, Texas. Description of the fracture systems may be applicable to hydrocarbon exploration and production from this unit and to locating the proposed Dallas-Fort Worth Area Superconducting Super Collider site in Ellis County. Inactive normal faults with throws of less than 30 m compose this northernmost extension of the fault zone. Most of the major faults strike northeastward to east-northeastward, oblique to the regional strike of bedrock, and dip 45° to 80° northwest and southeast. Smaller faults strike northwestward. Calcite mineralization occurs along most of the fault planes, and slickensides indicate normal to slightly oblique slip. Developed within the fault zone are a series of narrow grabens that are 250 to 600 m wide and as much as 5.5 km long. In plan view these small grabens occur either as (1) depressed strips of bedrock bounded by subparallel hinge faults that increase in displacement to the northeast or as (2) irregularly subsided blocks bounded by double hinge faults that increase in displacement toward the central part of the trough and pinch out toward the northeast and southwest. Areas of high fracture density within the Austin Chalk occur adjacent to the major faults and within gently warped beds located where faults terminate along strike. Narrow zones characterized by different fracture styles and densities occur subparallel to the major structures. These zones vary in width and are composed of (1) complex minor faults (2 m wide), (2) minor faults and joints (15 to 90 m wide), or (3) abundant joints (60 to 140 m wide). Most minor faults have throws of less than 3 m and strike subparallel to an associated major fault or flexure, although some minor faults strike subperpendicular to major structural trends. Minor faults dip between 40° and 70° and are usually partly filled with calcite. Most systematic joints are nearly vertical and also strike subparallel to an associated major fault or flexure. Joints are only rarely filled with calcite, and abutting relationships suggest that minor faults predate joints. Average fracture spacing near faults or within flexures for 0.5- to 1-m-thick chalk beds generally ranges from 0.5 to 1.3 m. Locally joint densities may be as high as 10 joints/2 m. Minor faults and many joints cut through adjacent beds of different thicknesses.

Supercollider site selection moves into final round

Supercollider site selection moves into final round

States To Bid Soon for Supercollider Site

States To Bid Soon for Supercollider Site