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Introduction
In June 1986, the Great Salt Lake was at elevation 4211.85.
Damages from high water had already amounted
to $250 million, and the lake was not receding. Various solutions to alleviate
the problem were proposed ranging from doing nothing to diverting entire rivers.
The scheme finally selected, and put into action, was the design and
construction of an emergency flood control project capable of pumping water from
the Great Salt Lake to the West Desert. The plan combined lowering the take with
the increased evaporative action of the climate. Construction for the project
began on July 7, 1986. The Pumping Plant was in full operation on June 3, 1987,
with three pumps capable of pumping nearly 1.4 million gallons of take brine per
minute.
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Design Contract
In July 1984, the state of Utah, Department of Natural Resources, Division of Water Resources,
contracted with the joint venture team of Morrison-Knudsen Engineers, San
Francisco, and Eckhoff, Watson and Preator Engineering, Salt Lake City, to
design and prepare construction drawings and specifications for the West Desert
Pumping Project Preferred Alternative. Estimated cost of the project was $80 million.
A revised "Bare Bones" version of the preferred alternative,
was eventually constructed. The revised design eliminated the long inlet canal,
the barrier dike and the return syphon. Cost of the revised project was an estimated
$52 million.
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Construction Management Contract
Up to May 1986, a decision to proceed with the construction of the project had not been made.
The lake by this time had risen to elevation 4211.65 and caused $250 million in
damages to the surrounding commercial, public and private properties. To
continue the gamble that the lake would start to recede was a risk that the state decided not
to take. On May 6, 1986, the Division of Water Resources notified the joint venture to submit
a proposal for implementing and managing the construction of the project, which was to
commence as soon as approval could be granted by the State Legislature and
Governor Norman H. Bangerter. The first unit was to be on line by February 14,
1987. The proposal was submitted within two weeks, including the engineer's
estimated schedule for construction, the estimated staffing for the construction
management team, and the estimated cost. Although an agreement had not been
finalized, the state directed the joint venture team to proceed with preparing
bid documents and arranging for the bidding phase. Several meetings were held in
May and June of 1986 between initial parties to the project; specifically,
Ingersoll-Rand, the major equipment supplier; the Southern Pacific
Transportation Company (SPTC); the state; and joint venture partners. During
this time a decision for a major design change from diesel driven engines to
natural gas driven engines was made by the state
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Construction Contracts
Due to the urgency of the schedule and following a June 1986 storm which
destroyed the SPTC's causeway, a "sole-source" contract between the
state and the SPTC was let in late June 1986. The excavation subcontractor for
SPTC, Lost Dutchman, Inc., was already on site as the SPTC's quarry
subcontractor, resulting in expedient mobilization of equipment and personnel.
The SPTC contract included excavating the Pumping Plant foundation, excavating
the Outlet Canal, constructing four bridges, reconstructing the damaged I 0-mile
causeway, and raising 25 miles of railroad track for an original total contract
price of $22,980.00.
Advertisement for bids for construction of the Pumping Plant and
Inlet Canal commenced in June 1986. Bids were opened on July 22, 1986, with Layton
Construction Co., Inc., of Salt Lake City, the low bidder out of seven submitted bids.
Bids ranged from a low of $7,891,378.68 to a high of $14,837,320.00. The engineer's estimate
was $12,891,583.85. Layton Construction Co., Inc., was awarded the contract on
July 31, 1986.
The contract for procurement of pumps, gear drives and engines was awarded to
Ingersoll-Rand of Painted Post, N.Y., for a total original contract price of
$7,829,378.68.
The containment dikes at the south end of the West Desert, known as the
Bonneville and Newfoundland dikes, were designed and bid through another
consultant at a total cost of $6,336,875 for both dikes. W.W. Clyde and Co was
awarded the contract for the Bonneville dike for a price of $3,872,845. The
construction contract for the Newfoundland dike was awarded to Herm Hughes and
Sons for a price of $2,464,030. These two contracts were outside the scope of
the West Desert Group's contract with the state.
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Organization
At the outset, due to the remote nature of the project approximately 110
miles northwest of Salt Lake City, no communications or utilities were at the
construction site. The storm that occurred in June 1986 also wiped out the main
vehicle access to the construction site from the base camp at Lakeside located
10 miles east of the site. Access to the site was then by boat from Lakeside, by
vehicle from the Nevada side of Wendover, or from the north traveling over 50
miles of the Hogup Mountain area. Consequently, it was necessary to utilize two
project offices; one on-site field office and one central office in Salt Lake
City for liaison between the project and the various headquarters of the
contractors, state and consultants.
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Project Construction
Lost Dutchman, Inc., began excavating the Pumping Plant on July 7, 1986.
Initial mobilization of its camp and equipment between June 7, 1986, the date of
the storm, and August 22, 1986, had to be done via Wendover, Utah, or via the
north through the desert due to the causeway repair work. The inspectors for the
consultant reached the work site by boat from Lakeside.
Excavation of the first 20 feet to 30 feet of the hole found little or no
groundwater. But after 30 feet the flow increased with depth until on August 11,
1986, it measured 12,000 gpm with the excavation at elevation 4179. The
contractor had gradually added to his original dewatering system, based upon a
geotechnical report which forecasted no more than 300 gpm.
Excavation of the Pumping Plant was completed on August 31, 1986, and the site
was turned over to the Pumping Plant contractor, Layton Construction Co., Inc. (LCI).
After verbally accepting the excavated foundation and dewatering system on
August 31, 1986, the contractor, LCI, requested further work by the previous
contractor prior to starting the mud mat. Consequently, on September 3, 1986,
the previous contractor excavated a drain trench connecting the west keyway of
the foundation with the pump sump located at the east end of the foundation in
the forebay. After that, on September 4, 1986, the LCI superintendent signed an
acceptance of the excavation and dewatering system. A french drain system
recommended by the engineer satisfactorily handled a flow of groundwater as high
as 12,000 gpm during construction of the Pumping Plant.
The concrete batch plant installed by LCI's concrete supplier, CPC, was a
mobile, low profile, dry batch plant. Approximately 15,000 c.y. of concrete was
used in the Pumping Plant. At least 3,000 c.y. of this total was due to overbreak and concrete added for a
cutoff key under the siphons and a training wall on the right side of the
afterbay.
The first lift of structural concrete was for the base slab. It required 1,900+
c.v. and took two days to place, working around ihe clock. The lift was
completed September 24, 1986.
The contractor's initial schedule indicated the engine deck at elevation 4230
would be placed no later than November 20, 1986. Allowing 14 days extension of
time for delays not attributable to the contractor would have extended this date
to December 3, 1986. Allowing another 17 days extension of time for the delay
caused by the flooding of the Pumping Plant excavation, the initial schedule
would have had the engine deck placed no later than December 20, 1986. A minimum
of seven days strength gain, or actually 14 days over the Christmas holidays,
would have enabled the electrical and mechanical subcontractors to move in and
commence very critical work no later than the first week of January, 1987. If
all other contract dates were extended by the 31 days mentioned above, the first
unit should have been ready for testing by March 17, 1987.
To ensure that the roof cover could be expedited, a design change was made from
castin-place concrete roof slab supported by shoring the false work, to "permi-form"
construction using galvanized steel Q-decking as the permanent form support for
the concrete to be placed at a later date. This alone saved the time which would
have been necessary to install shoring and false work, place and cure the
concrete, and remove the shoring and false work prior to installing the plant
engines and auxiliary equipment - probably a month at least. The contractor
agreed to a trade-off for the costs of the Q-decking versus the costs of
the labor, materials and time for shoring and false work.
Another recommendation by the engineer was to use Type III high early strength
cement in lieu of Type 11 as specified. This would have required a modification
to the batch plant for which time did not allow. Instead, it was decided to use
3,000 p.s.i. concrete in lieu of 1,500 p.s.i. concrete in the lifts designated
as mass concrete. This gave higher strength at an earlier date in these lifts,
but at a higher cost.
In November 1986, with the idea that the engine deck would be placed and the
roof covered no later than January 10, 1987, the engine and pump supplier,
Ingersoll-Rand, was requested to expedite its shipping schedule for the Unit I
engine and pump components. The original schedule had the engine arriving
January 30, 1987. If the contractor met his most recent schedule, this would
mean that the mechanical and electrical subcontractors would have had to wait
approximately two weeks until the engine was set in-place before they could have
started work for final connections. Due to space restrictions, some of the
auxiliary equipment could not be moved into the plant and set in final position
prior to the setting of Unit 1.
Minor piping work had proceeded in the lower structure along with the
preparations for concrete, and a major amount of piping was installed following
the placement of the gallery deck at elevation 4221 in December, 1986. This
piping was for cooling water, lube oil, natural gas, potable water, drainage and
instrumentation.
Prior to placing the engine deck, the electrical contractor installed all the
conduit which was to be embedded in the stab. Still another design change
intended to save valuable time was the relocation of a major portion of the
electrical conduit from this slab to hangers along the precast panel walls for
the superstructure. The engine deck was placed on January 29, 1987
The main pump components for the three units were the lower embedded rings, the discharge elbows, upper embedded frame
supports, shafts and impellers, outer casings, suction bells, upper casings,
diffusers, and gear support structures. The tolerances for the lower embedded
rings were to 0.0005 inch per foot in level across the ring diameter. Pump
erection for the embedded parts was second stage for the lower embedded rings
and the upper frame supports, and the first stage for the elbows and columns.
The installation of the rotating parts, outer casings and suction bells was then
paralleled with other construction activities and subcontracted to a division of
IngersollRand.
The engine for Unit I arrived in Salt Lake City on January 10, 1987, and was put
on public display at the Department of Natural Resources Building parking lot
before being moved to the plant site. At the project site, the contractor did
not unload the engine from the transporter until January 19, after which time
the engine remained on its parking slab until the engine deck was ready to
receive it on February 6, 1987.
The method used to yard in the engine to its final position in the pumping plant
was a system of rails, hydraulic come-alongs, and hydraulic jacks on trucks that
ran along the rails and supported the weight of the engine, plus skids ( 165,000
lbs.) by steel beams spanning the tops of the jacks. The rails were segmented so
that sections could be removed from under the engine prior to setting it down.
Once finally positioned, the engine was grouted with special epoxy grout which
required careful thermal control. Each engine was set in this manner.
Before the first engine was yarded in, the two Cummins natural gas driven
generators were set into place through the incompleted roof covering by crane
and jacked into final position. Other auxiliary equipment which had to be set
before the first engine was moved in were the engine control panel, plant and
instrument air receivers, and the compressors.
The gear reducer equipment for Unit I was set into place following the setting
of the engine. Then followed the heat exchangers and cooling water surge tank
for that unit. Due to space restrictions, this was the sequence followed for
each unit. The mechanical subcontractor was then able to commence piping between
the various pieces of equipment.
On February 11, 1987, the engineer submitted a feasible schedule for attaining a
"ready-to-start!' date for Unit I no later than March 23, 1987. The
contractor used this schedule with some modifications to submit his schedule to
meet this date with an accelerated program. Preliminary discussions with the
contractor had resulted in a new change order on the basis of a bonus plus time
and materials for the accomplished of this schedule. With a good effort by all
his subcontractors, the first unit was ready to be tested by March 26, 1987.
Following initial system tests, the engine was "bumped" on April 4,
1987, at 15:00 hours. The following day, Governor Norman Bangerter officially
started the Unit I pump by remote switch at a public ceremony at the plant. All
went well.
Other construction activities which paralleled the above installation work, and
which were necessary for the successful operation of Unit 1, were the completion
of the service building control room with the motor control center and switch
gear, installation of the 24-inch vacuum breaker butterfly valves on the
afterbay deck, installation of the two vertical shaft cooling water pumps in the
sump well, completion of the trashrack and stoplog guides and their
installation, testing of the dewatering pumps, installation of the gantry crane,
removal of the intake canal cofferdam, and prewatering up the outlet canal and
afterbay so that the initial surge of water from the pumps would not scour the
channel.
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Intake Canal Excavation
Layton Construction Companys subcontractor for the Intake Canal was BECHO,
Inc. They started on August 18, 1986, grubbing and clearing the area between the
forebay and the waterline of the lake on the south side of the SPTC railroad
track. The canal extends from the forebay of the plant 1,200 feet to the
railroad bridge which crosses over the Intake Canal and into the north arm of
the Great Salt Lake. The canal bottom daylights to elevation 4208 in the lake
from elevation 4190 in the principal channel. It drops to elevation 4175 at the
intake sill of the plant in the forebay. The forebay of the plant was excavated
by Lost Dutchman, Inc., subcontractor to SPTC, at the time the foundation for
the plant was excavated.
BECHO started excavation on the land reach south of the railroad using dozers
and backhoes, The first 200-300 feet from the beginning of the forebay was in
blocky limestone. So it was drilled, loaded and shot, and the material was used
for construction of the diversion dike which parallels the southern bank of the
canal on the south side of the railroad. Later, BECHO mobilized a dredge to
complete the excavation of that portion of the canal inundated by the lake.
Final removal of the plug dike upstream of the forebay was completed in late
February 1987. The total amount of excavation for the Intake Canal was 99,379
c.y. common and 20,000 c.y. rock.
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Outlet Canal Excavation
The SPTC's subcontractor, Lost Dutchman, Inc., excavated the Outlet Canal.
Work started in July 1987 and was completed on schedule in February 1987. The
canal extends 4.11 miles westerly from the afterbay of the plant to a SPTC
railroad bridge, Hogup
Bridge, at milepost 719.06 where the canal daylights and canal flow is
discharged as sheet flow onto the desert north of the railroad. From there the
sheet flow advanced along the north side of the railroad a distance of 15.9
miles to another railroad bridge, LeMay, at milepost 703.09, where the flow
returned to the south side of the railroad and on a southerly course toward the
west evaporative pond.
Design of the outlet canal took into account the nature of the soils to be
encountered and the hydraulics of flow to be accommodated. Sections varied from
45 feet bottom width and 11/2:1 side slopes in rock to 90 feet bottom width and
2:1 side slopes in clay and sand. The flow depths ranged from 16 feet at the
afterbay to 10 feet in the lower reaches.
The contractor utilized various equipment throughout the project, depending upon
the material encountered. A dragline was used for the last mile of canal before
its discharge onto the desert flood plain. In the upper reaches, a Holland
scraper and belt loader, pushed and pulled by D-9 tractor dozers, was used with
a fleet of 50-ton rock wagons until the sail became tbo wet for its practical
production. Other equipment used was a fleet of scrapers and as many as seven
large backhoes. The contractor worked around the clock, supporting his labor
force with a well-organized man camp at Hogup, as well as in Lakeside.
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