Progress Photos

May 2009

Girder tops with pre-cast concrete deck panels in between awaiting final deck reinforcing.		Reinforcing steel being delivered by crane to steel placers working on the viaduct deck.
Green corrosion resisting epoxy coated reinforcing steel in place for the deck pour.		A deck finishing machine assures the correct slope and grade as fresh concrete arrives.
Workers rake and vibrate fresh concrete into the reinforcing steel mat to eliminate air pockets.		Finished concrete deck slowly cures as the process continues further down the viaduct.

April 2009

In preparation for girder erection, cranes lift temporary supports, known as stiff backs, into place.		Each of the four girders require a stiff back support to span the splice between segments until the closure pour is completed.
Post-tensioning cable ducts are visible in this view. The post-tensioning cable ducts align with the ducts in the drop-in segment.		Stiff backs, which are formed of structural steel, remain in place until girders are permanently spliced.
Workers prepare to temporarily secure the first drop-in segment as it is lifted into place.		The first drop-in segment straddles the railroad tracks as cranes are attached to each end and prepare to lift it into place.
As seen from one of the stiff backs, the first segment is on its way.		In this view from the ground, two drop-in segments are seen in place and the third is on its way.
A small splice space is formed between girder segments. The space will be closed with the concrete closure pour.		Two cranes are used to lift the drop-in girder segments. View is from the viaduct abutment.
Workers position the powerful jacks that will tension the cables and turn several girder segments into a single girder.		Precise tension is applied to each group of cables at the abutment end. Cables will then be permanently capped.
Closure pours are complete (dark vertical bands) and the girders tensioned. Cranes again prepare to lift stiff backs.		Stiff backs are being removed. The four completed long span bridge girders are ready for roadway decking.

January 2009

The contractor prepares to place concrete paving in the shoulder of I-25		A conveyor delivers fresh concrete to a paving machine which shapes the rough surface
Workers following the paving machine give the shoulder a finished driving surface		After a standard curing period a core is drilled by inspectors to test pavement quality
Inspectors test concrete pavement dowel bar location and verify bar depth		A new wall and riprap (stone) installed at the Commercial St culvert which drains NW Trinidad
The north I-25 abutment formed and ready for steel reinforcing bar placement		The north I-25 abutment with steel reinforcing in place and ready for enclosing formwork
Workers build formwork for a viaduct pier diaphragm		Viaduct pier diaphragm showing reinforcing at the terminus of the post tensioning cables
A center segment for the long variable depth Railroad spans sits on blocks ready for placement		View of the Railroad span awaiting placement of the center segments
Construction continues and portions of the project are beginning to look finished.

December 2008

Final grading of the non-structure portion of NB I-25		Paving operations lay 12" of Portland Cement Concrete Paving
The contractor's concrete paving machine in action laying pavement		Trucks deliver pavement to the back of the paving machine
From this view of the viaduct the temporary stiffeners are visible between the walls of the box girders		Workers will soon be preparing the girders to receive formwork for placing the deck
Construction team pre-erection meetings ensure that girder placement proceeds safely and efficiently		Cranes set the large variable depth girder segments cantilevered from piers near the railroad
These variable depth girders are used to create the long span necessary to cross the railroad		The deepened section of the variable depth girder occurs over the supporting pier
Workers re-install the original historic brick pavers in Commercial Street which were removed and stored at the beginning of the project		Many of Trinidad's brick paved streets were declared protected historic components of the Corazon de Trinidad Historic District in 1977

October 2008

Northbound I-25 north of Commercial Street at final grade and ready for paving		Barrier reinforcing waiting for concrete on the viaduct and the Commercial Street off-ramp
Placement of steel reinforcement at Commercial off-ramp		Girders at Nevada Ave
Girders over College St		Girders north of Railroad tracks
Northbound I-25 north of Van Buren at final grade and ready for paving		MSE walls and abutments near final heights at Main Street bridge
Slip formed Type 7 barrier on the Purgatoire River bridges
The Main Street overpass MSE abutments near completion.		Work continues on the MSE wall leading up to the Main Street overpass.
The contractor continues to place girder segments for the viaduct and the Commercial Street off-ramp.

September 2008

Construction cranes prepare to set girders on the south end of the viaduct which includes the long span that crosses the railroad.		Workers measure and fabricate the temporary steel-cross bracing and shoring towers that will secure the concrete girders during construction.
Cranes place the first segment of the pre-cast post-tensioned segmental concrete box girder.		The concrete segments will be tied together or 'tensioned' after all the segments are in place.
The girder is tensioned with heavy cables threaded through reinforced steel ducts which are cast into the walls and floor of the segments.		Temporary shoring towers support one end of the segment until adjoining segments are placed and the girder is tensioned.
The post-tension girder allows a long span to clear the railroad with minimal structure depth and cost. Note the duct openings at the end of the segment (floor of girder) through which the cables will be threaded.		Workers mount temporary steel cross-bracing to prevent movement until the adjoining segments and deck are in place.

August 2008

Crews place reinforcing steel for the concrete deck of Unit 3 of the Northbound viaduct. The deck of the viaduct is poured in monolithic units.		View of deck reinforcing steel with a noticeable super-elevation slope for the roadway curve.
Final inspections and adjustments to the steel prior to placing or 'pouring' concrete.		A concrete pumper truck begins pumping fresh concrete into the Unit 3 deck.
Workers vibrate the fresh concrete between the reinforcing steel bars to prevent voids.		Once the pour reaches the proper level workers finish the surface of the new deck.
Inspectors perform tests on each load of concrete to ensure quality.		As concrete continues to arrive during the night, inspectors continue to test.
The concrete pour (monolithic) for Unit 3 continues through the night until the unit is complete.
Earth movers lay in the final lifts for the Commercial Street off-ramp between MSE walls.		The Commercial Street ramp at rough grade, covered and waiting for roadway surfacing.
New curb and gutter completed on the Commercial Street exit ramp.
The last of the Northbound viaduct piers ready for girders.		Main Street abutment ramp walls waiting for final I-25 grade and upper layers of MSE panels.

July 2008

Pre-cast bridge deck panel installation on the I-25 NB viaduct.		Pre-cast bridge deck panel installation on the I-25 NB viaduct.
Concrete paving on NB I-25 to Main Street off-ramp.		Northbound Main Street on-ramp and MSE retaining wall.
View from under the Commercial Street off-ramp.		Commercial Street off-ramp.

June 2008

Contractor placing Portland Cement concrete paving and curb and gutter on Commercial Street.
		See the Benefits to Trinidad page for more information about local contractors and suppliers.

May 2008

Pre-Cast Concrete Box Girders top viaduct piers near Commercial Street.		MSE retaining wall for the Main Street on-ramp nearing completion.
Construction cranes place pre-assembled steel reinforcement into the forms of a Viaduct Pier.
Mixer and Pumper trucks place concrete for the last of the Northbound Viaduct Piers.
Workers place concrete paving and barriers on the Commercial Street Ramp

March 2008

Mainline Overpass at Main Street being prepared for deck placement.		North Abutment of the Mainline Viaduct from Commercial Street near the Amtrak Depot.
Northbound Ramp Structure over Purgatory River from the SH 12 Extension bridge completed during Phase I of the project.

February 2008

Workers use cranes to set concrete girders for the bridge at Northbound I-25 over Main Street.		Northbound Viaduct and Northbound Commercial Street Off-Ramp.
Northbound Viaduct and Northbound Commercial Street Off-Ramp.		Purgatoire River Bridge Girders and Piers.
Purgatoire River Bridge North Abutment.		Main Street Northbound On-Ramp.
Electrical conduit installation at College Street.

Progress Photos: 2007 - click to view photos of construction progress during 2007.