From: wylie@sscvx1.ssc.gov (Russ Wylie)
Newsgroups: sci.physics
Subject: SSC:  4th Tunnel Contract Awarded
Date: 5 Oct 92 20:08:55 GMT
Article-I.D.: sunova.1992Oct5.200855.3153
Distribution: all
Organization: External Affairs, Super Collider Lab








Contact:  Russ Wylie
      214 708-1045

IMMEDIATE RELEASE
DALLAS, TX. -- (Friday, October 2, 1992) -- A $27.1 million general 
construction contract has been awarded to a joint venture of Gilbert Texas 
Construction Corp., of Omaha, NE, and Fort Worth, TX, and J. F. Shea Co., 
Inc. of Walnut, CA.  The contract will cover the construction of an 
8.5-mile-long segment, including eight shafts, of the 54-mile underground 
tunnel that will house the Superconducting Super Collider particle 
accelerator, the world's largest instrument for basic research into the 
fundamental nature of energy and matter.  Completion is expected by 
October 1994.
The contract is the fourth to be awarded since February for construction 
of the tunnel, one of the largest tunneling projects in history.  Total 
tunnel length now under contract is 22.2 miles, nearly half the total 
circumference.  The four awards bring the value of tunnel contracts to 
date to $83.2 million, 27 percent less than baseline estimates.  
The contract to Gilbert Texas and J.F. Shea was awarded by the 
Superconducting Super Collider Laboratory's construction management team, 
a joint venture of Parsons Brinckerhoff Quade & Douglas, Inc., and 
Morrison Knudsen Corp. (The PB/MK Team).  Construction of the 8.5-mile 
tunnel segment, the largest awarded to date, will start at service area 
N40 on the north side of the collider ring and continue southeasterly to 
site N55, eight  miles east of the City of Waxahachie.
The collider tunnel will be in Ellis County, which lies south of the 
Dallas-Ft. Worth Metroplex.  Waxahachie is roughly in the center of the 
area encircled by the tunnel.
A tunnel boring machine (TBM) will tunnel the N40-N55 segment primarily 
in Austin Chalk, a stable rock through which most of the collider tunnel 
will be drilled.  The tunnel will have a finished interior diameter of 14 
feet.  A computer-aided control system will guide the TBM to ensure proper 
tunnel alignment.  For tunnel segments in Austin Chalk, reinforcement 
where required will be applied with fiber reinforced shotcrete and 
installation of rock dowels.  Precast concrete floor segments will be 
installed throughout the tunnel.
A shaft, the first of eight, will be excavated during the first six 
months of the contract term to provide access for the TBM.  The other 
seven shafts and tunnel excavation will follow.  The shafts will provide 
ventilation, utility connections, and access for personnel, equipment, and 
delivery of collider components.  Five of the shafts will be excavated in 
Austin Chalk.  The three shafts to be located at the N55 site will be 
excavated mainly within Taylor Marl, a formation more sensitive to 
moisture.  The shafts will range in depth from 115 to 185 ft.  
Additionally, 28 niches located along the tunnel length will house 
electrical and mechanical equipment to support collider operations.
The Superconduting Super Collider Laboratory is operated for the U.S. 
Department of Energy by Universities Research Association, Inc., a 
not-for-profit consortium of 79 leading research universities in the 
United States and Canada.

(10/2/92)

Russ Wylie, Director, External Affairs,
Super Collider Laboratory
Dallas, TX 75237
214 708 1045; FAX 214 708 0000
Newsgroups: sci.physics