Spring 1998 Newsletter
Los Angeles Metropolitan Transit Authority (MTA) Contract C311 calls for the construction of twin rail tunnels under the Santa Monica Mountains from Universal City in the San Fernando Valley to Hollywood Boulevard in the Los Angeles Basin. The Contract was awarded to the Joint Venture of Traylor Bros. and Frontier-Kemper Constructors, Inc. (Traylor Bros./FKCI), for the sum of $124,421,000. Notice to proceed was given on January 25, 1995 for a contract period of 44 months. The contract includes: A crossover excavation, 360ft long, 60ft wide by 85 ft deep; 12,000 ft of twin bore, 18ft internal diameter tunnels; 19 cross-passages of varying lengths from 18 to 80 ft between the running tunnels; a 600 ft long larger diameter section through the Hollywood fault zone (Special Seismic Section); two track crossovers between the tunnels at up to 50ft wide x 30 ft high x 420 ft long; and Track Level Rooms at 21ft high x 34ft wide and 330 ft long. By Change Order, an additional 3,400 lf of tunnel concrete lining and finishing works was added to the southern portion of the Contract and the two track crossovers were deleted. The running tunnels were excavated by Tunnel Boring Machine and the crosspassages, crossovers and track level rooms by conventional drill and blast methods. Two starter tunnels under the 101 freeway had to be excavated from the crossover site before TBM excavation could commence. The alluvium soil in this area was chemically grouted prior to the starter tunnels being excavated by the top heading and bench method, using small road headers. Currently, the crossover excavation and the starter tunnels at the north end of the project are complete. Both TBM driven tunnels have been excavated. The Special Seismic Section has been completely excavated to a reduced length of 300 ft and ten cross passages have been excavated and concrete lined. The added 3,400 lf of tunnel has been concrete lined and is ready for the placement of walkway concrete. Invert concrete has been placed in over 50% of the #1 Tunnel and 20% of the #2 Tunnel. Arch concrete operations will begin shortly from Universal City, heading south. Change Orders Affecting Tunneling; The Consent Decree Community concerns over the effects of construction on the community lead initially to an MTA Board motion and eventually, in June 1996, to a binding legal agreement between MTA, Friends of Runyon Canyon and other concerned parties. This agreement, known as the "Consent Decree," required the MTA, amongst other things, to protect the Seasonal Springs above the tunnels by grouting both before and after the passage of the TBMs. Geology The tunnel alignment passes through the eastern portion of the Santa Monica Mountains between Hollywood and the San Fernando Valley. The general geology is that of a faulted, east-west anticline that has a core of metamorphic and volcanic rock formations. Six distinct formations cross the alignment: (1) Upper Topanga Formation (Sandstone and Siltstone/Shale) - Reach 6; (2) Upper Topanga Formation (Sandstone) - Reach 5; (3) Middle Topanga Formation (Basalt and Basalt Breccia) - Reach 4; (4) Lower Topanga and Las Virgenes Sandstones - Reach 3; (5) Chico Formation and Simi Conglomerate - Reach 2; and (6) Volcanic Rocks - Reach 1. The varying geology of the Santa Monica Mountain Range proved to be a formidable task for both man and machine. Timely modifications to the TBMs, excavation methods, and both the initial and final designs, have allowed for these difficult tunnel drives to be categorized as a success. Numerous and frequent design changes continue to affect this project. To date, 183 Change Notices have been issued, resulting in 97 Change Orders and a substantial increase in the Contract value.
The new year is off to a good start with the Sailboat Bridge Project in Grove, Oklahoma, beginning on January 5, 1998. Our Casting Yard is up and running as evidenced by our pouring the first of 356 segments on February 17, in spite of an abnormally high amount of rain and snow for the area. Our equipment is continuing to be mobilized and exploratory drilling for drilled shafts is well underway.
So far, construction of a cable stay bridge in Maysville, Kentucky, seems to be an endurance test between our bridge gang and Mother Nature. We have weathered the "100 year flood of March 1997," record snowfall amounts of 20-24" in February of ’98, and without a doubt, we will probably have a killer heat wave this summer. Despite "Mother’s" best shots, construction is proceeding right along. To date, we have completed and removed our first cofferdam at Pier 6 and have gotten our concrete work 67 ft above the river. We are eagerly awaiting the March delivery of the Aluma Form Systems "jump forms." These two forms will be used to construct the tower legs to a height of 305 ft above the river. As work was proceeding on our first river pier, the drill crew became "landlubbers" and engaged in their own version of landscape work! While confined on land, they successfully completed our 96" "technique shaft" and moved on to the Osterberg load cell test shaft. After all the data from the load test had been reviewed, the four remaining production shafts were completed. Secure in the knowledge that they had ravaged the area to the best of their abilities, the crew and company once again became waterborne. Floating again, they reconstructed the cofferdam at Pier 5 and currently have completed 10 of the 16 72-inch shafts at this location. When finished here, they will once again perform their landscape wizardry on the Ohio bank and complete the list of the drill shafts on the job, two 96-inch shafts. On the Kentucky side, only two caps remain to complete the substructure work on land. We will then race with Mother Nature in bringing our foundation work above water at Pier 5 cofferdam. The casting yard has begun casting the first of 256 precast slabs which will make the roadway of the cable stay portion of the bridge. With only one more mass concrete pour to go at Pier 6, the General Superintendent looks forward to spending more time advancing our concrete work and less time spent wrapping our pours in insulating blankets to meet our thermal control specs. We are ready to get winter behind us and get into the tasks that lie ahead. Lastly, our office staff has put aside our snow shovels for now and continue to deal with the vast amount of paper work this job seems to generate. With a little help from "Mother Nature," we look forward to a safe and productive year.
With springtime quickly approaching, those of us at the Vincent Thomas
Bridge Seismic Retrofit will all be happy if we never hear the words "El
Nino" again. After this year’s record-breaking rains and severe storms
interrupted our work and taught all of us more than we ever wanted to know
about Storm Water Pollution Control, we are once again ready to get back
to work. Progress on the concrete work has been most affected by the weather,
but as of this writing, the footing work is being wrapped up and we are
nearing 50 percent completion on the superstructure concrete. Overall completion
of the concrete and civil work is scheduled for the end of this summer.
The structural steel work had been delayed by a series of owner-driven
design changes that now appear to be complete. Work began in mid-January
on the replacement of the bottom laterals in the suspended truss over the
shipping channel. Shortly after we started, work was once again interrupted
when an errant derrick barge (belonging to another contractor) ran into
a section of the bridge, causing structural damage and wiping out the access
to our work areas. Traylor Pacific immediately began and rapidly completed
the emergency repair work needed to fix the bridge and get us back on track.
With all of these scheduling "challenges" behind us, the Ironworkers are
now rushing to complete work in an area of the bridge that is home to the
bridge’s resident Peregrine Falcon. This Falcon is an endangered and protected
species, and we are prevented from doing anything that would interrupt
its nesting season. Falcons are known to attack humans, and we are interested
in completing our work as rapidly as possible. The lateral replacement
work is being completed by use of a rather unique and highly successful
rigging system. Replacement of these 40’ long, 2 ton pieces is being done
sequentially, with one piece being removed and replaced before moving on
to the next. We, therefore, needed a rigging system that would move the
existing pieces from their position in the bridge approximately 1,100’
laterally and 175’ vertically to the nearest on-site landing spot, and
then transport the new pieces into position. Contract requirements prevented
us from using a crane on the bridge deck to move steel, and we felt that
we could not economically work off of barges in the heavily traveled shipping
channel. So we developed a "Slack Line" rigging system which moves the
structural steel pieces from the base of one of the bridge towers on land
to their position in the bridge. This system utilizes three 21,000 pound
line pull air tuggers mounted at the base of the tower and rigging and
hoisting cables strung throughout the bridge suspended span. It has been
a highly effective solution to our problem, and is now providing the whole
division with new ideas of how to handle similar engineering problems on
other jobs. Now that this problem has been solved, our structural steel
management team is concentrating on preparing for our upcoming challenges.
In the next few months, we will begin work in breaking open the stiffening
truss in several locations to install new hinge points, and will begin
work in the major structural truss modifications at the towers and cable
bents. Additionally, we are required to jack the bridge at the approach
bents to replace the bearings. And last but perhaps most important, we
are all extremely proud of our safety record. As of this writing, we have
completed over 50,000 manhours without a lost time injury. Congratulations
to everyone for a job well done.
Welcome to Fort Lauderdale, Florida the yachting capital of the world,
the Venice of America, the winter home of millions, where every other car
has out of state plates and the turn signal is on non-stop. On June 27,
1997, Traylor Bros. was the low bidder on the 17th Street Causeway Bridge
Replacement Project with a low bid of $61,348,262.72 and an aggressive
1000 day construction schedule. The project was designed to be Fort Lauderdale’s
"Signature" bridge. The new bridge will have more than double the existing
vertical clearance (new vertical clearance will be 55 ft.) and increase
the channel width from 100 ft. to 125ft. These improvements should reduce
the number of openings by 48 percent, thus greatly reducing the vehicular
traffic congestion in the area and also allow the majority of the boats
to pass without having to wait for a bridge opening. By the end of the
year 2000, Fort Lauderdale is to awaken to a new millennium and a remarkable
new bridge, which blends engineering efficiency and artistic flair into
service to a great community. Three months to the day after the bid opening,
our directional drilling subcontractor (Piute Contracting) mobilized and
began work on installing 325m of 30" HDPE pipe for a water main and 350m
of 30" HDPE pipe for a force main under the intracoastal waterway. After
being stymied by some unforeseen obstructions in the drill path, the pipes
were successfully completed on December 23rd. On November 10th, we began
our work for Phase 1. Phase 1 consists of building the temporary bridge
approach spans and approach pavement up to an existing bascule pier that
is being installed under an earlier contract. The temporary bridge consists
of 508 mm dia. steel pipe pile (which started being installed 12-8-97 and
we have installed approx. 1500 m) with precast caps and precast 200 mm
& 400mm deck panels then a 50mm asphalt riding surface. We have cast
the precast caps and the 200mm deck panels at the cast yard we set up.
The 400mm deck panels are being cast by Standard Concrete Products of Tampa.
This temporary bridge becomes our property when we complete the permanent
north bridge. Does anyone want to buy a bascule bridge? If you do please
call our business manager & bridge broker at (954) 467-0056. We have
cleared the site of trees and have completed the clearing and grubbing
of the approaches. Our subcontractor (Gimrock Construction) has installed
approx. 2900 m2 of steel sheet pile walls for the approaches and we have
completed the embankment up to the subgrade. We are scheduled to open the
temporary bridge on April 10th, 1998. Our drilled shaft subcontractor (Gimrock)
has completed the precoring operations of the drilled shafts that are available
in Phase 1 and has started the test drilled shaft program. In this contract
we have 6 statnamic test shafts, 3 osterberg test shafts, and 2 lateral
load test shafts. There are a total of 116 1.22m drilled shafts in the
project, with 60 of them being in the water. When the temporary bridge
is completed, we will place 2 lanes of traffic EB on the temporary bridge
and shift the 2 WB lanes to the south half of the existing bridge. We will
then begin removing the north half of the existing bridge to allow the
new north bridge construction to begin. Phase 2 consists of constructing
a 581m precast segmental bridge that is 16.29 m wide with a double leaf
bascule pier over the intracoastal waterway. The unique feature of the
bridge besides the variable depth precast segments is the "carina" bascule
piers. "Carina" is from the Latin word for "keel" and "the pier is supposed
to give the observer a sense of form and fluid motion that changes with
each new vantage point." During Phase 2, we will pour over 2600 m3 of concrete
in the bascule piers alone! The bascule piers require a tricky 2 phase
cofferdam to be installed. We have a time table of approximately 1 year
to complete this phase, allowing us to place all the traffic on to this
bridge. This is scheduled to be around June 1999. (Remember the temporary
bridge is for sale!) Phase 3 consists of removing the existing bridge and
the temporary bridges before constructing the twin to the phase 2 bridge.
Phase 3 also has us tying into the cofferdam from phase 2 at the bascule
piers and also installing a demolition cofferdam around the existing bascule
piers to remove their foundations. We also build the permanent control
house for the bridge in this phase. It is designed to give the bridge tender
a beautiful 360 degree view through bullet proof glass. This phase also
has a construction time of approximately 1 year. Phase 4 is the clean up
and completion of the project. We will be installing the friction coarse
on the asphalt paving, installing asphalt parking lots under the bridges,
installing fender systems out at the channel, installing a concrete bulkhead
along the west shore, and building bus shelters and bus stops. Our precast
yard is set up and we are scheduled to start production of the precast
segments in early March. There are more than 260 variable depth precast
segments (approx. 8100 m3) to be cast. The yard has already cast all the
precast caps and 200mm deck panels for the temporary bridge. The critical
path of the project consists of the construction of the bascule piers and
the installation of the related machinery and controls. Our subcontractors
Gimrock Construction, Designed Traffic Installations, Inc., Acutec, Inc,
and V&M Erectors and our major suppliers PDM Bridge (formerly Sheffield
Steel) and Philadelphia Gear Corp. are going to weigh heavily in the meeting
of our milestones and project incentive bonuses. Some notable statistics
about the job. Our contract includes 113 1.22m dia. drilled shafts, 5500
m2 of steel sheet piling for temporary walls, 8 cofferdams that are adjacent
to the intracoastal waterway channel, 5000 m of curb and gutter, 5,500
m2 of sidewalks, 2300 m2 of MSE retaining walls, close to $1,000,000 in
landscape work, two 762mm directionally drilled pipelines under the intracoastal
waterway, 880,000 kg of steel in 4 bascule leaves, 1.2 million kg of rebar
in the superstructure, 1.4 million kg of rebar in the substructure, and
45,200 m2 of asphalt paving.