Archive: Phase I Construction History and Photographs

Construction of Phase I, the reconstruction of the extension of SH 12, began in Summer 2003. Construction was complete and, following the ribbon cutting event on Tuesday, August 3, 2004, the Purgatoire Bridge in Trinidad was opened permanently. Below is an archive of the construction process in notes and pictures.

Construction August 2004 Ribbon Cutting Event for the Official Opening of the SH 12 Extension:
Right to Left: Trinidad and Las Animas County Chamber of Commerce president Kim Pacheco, CDOT Region 2 Project Manager Joe Garcia, Mayor Joseph Reorda, CDOT Deputy Executive Director Peggy Catlin, CDOT Region 2 Regional Transportation Director Bob Torres, Mayor Pro-tem Nick DeBono, and City Councilwoman Jennie Garduņo participating in the Ribbon Cutting Event marking the Official Opening of the SH 12 Extension and the Purgatoire Bridge on August 3.
Left to right: Mayor Joseph Reorda, Peggy Catlin, Bob Torres and Bill Lawrence of Lawrence Construction.		Left to Right: Trinidad City Manager Jim Soltis, City Council Members Joe Bonato, Herm Heise, Nancy Ellis, Mayor Pro-Tem Nick DeBono and Mayor Joseph Reorda.
CDOT and Consultants from Felsburg Holt & Ullevig and Figg Engineers.		Peggy Catlin, Deputy Executive Director of CDOT
Bob Torres, Regional Transportation Director for CDOT Region 2		Honorable Joseph Reorda, Mayor of the City of Trinidad
Flags adorn the Purgatoire Bridge for the Ribbon Cutting Event.		Another view of the finished Purgatoire Bridge during the event.
Finished Purgatoire Bridge and Streetscape elements for SH 12 Extension:
Finished and open Purgatoire River Bridge showing the west side of the structure.		Finished and open Purgatoire River Bridge showing the east side of the structure with the pedestrian overlooks.
Southwest style planters in place and planted as part of the aesthetic design elements for the SH 12 Extension.




Construction July 2004 Streetscape elements for SH 12 Extension:
Sidewalks and street amenities under construction along the SH 12 extension.
Finishing touches on the SH 12 Extension Bridge:
Detail view of the fully faced abutment columns. The facing consists of native sandstone.		Detail view of the pedestrian overlook.
Detail view of the freshly coated railings above the pier.		Formwork for the second pedestrian overlook.
River view of the nearly complete SH 12 Bridge fascia showing structural concrete coating on the railings and piers. Placement of the native stone facing has started on the lower part of the abutment columns. The girders await a darker toned structural concrete coating.
Construction June 2004
View from below showing the exterior facia and railings of the nearly complete S.H. 12 Extension Bridge over the Purgatoire River. The pier cap and column are visible in the foreground.		Detailed view of the cast balustrade railings and the pedestal features being clad with local stone veneer. Note at the top of the pedestal, the protruding electrical conduit that will provide power to the historical light fixtures to be mounted above.
Automobile perspective view of the nearly complete S.H. 12 Extension Bridge over the Purgatoire River showing the balustrade edged pedestrian walkways.		Local suppliers at work on the I-25 Trinidad construction site. In the foreground are visible precast concrete balusters that will be used in the pedestrian railing on the S.H. 12 Extension Bridge over the Purgatoire River.




Construction February 2004 Site Work and Retaining Wall Construction:
Tying rebar for retaining wall at Safeway.		Forming retaining wall at Safeway.
Clearing and grubbing (cleaning area) for installation of new 84 inch drainage pipe.		Compacting around 24" RCP pipe.
Bridge Deck Construction on S.H. 12 Extension over the Purgatoire River:
Setting metal bridge deck forms.




Construction to January 8, 2004 Bridge Girder Construction:
Bridge Girders being delivered.		Bridge Girders being delivered.
Bridge Girders being set.		Bridge Girders being set.
Bridge Girders being set.
Retaining Wall Construction:
Retaining wall footer By Sonic Drive-in.		Retaining wall (rebar) by Sonic Drive-in.
Retaining wall (rebar) by Safeway.		Pouring concrete for footer by Sonic Drive-in.
Pouring concrete for footer by Safeway.		Retaining wall by Safeway.




Construction to December 1, 2003 Abutment Construction - the contractor fill the forms for Abutment 1, the South Abutment, with concrete. This work will complete this stage of construction for this abutment. The next stage of abutment construction will not occur until after the bridge girders are set in place.
Workers ready to pour concrete for Abutment number 1.		Again a crane lifting a large funnel bucket is used to get the concrete from the transporting trucks over to the abutment location.
The bucket is guided into place over the form by workers and dumped. The concrete is vibrated into the form and the exposed surfaces are trowel finished.		The lower portion of Abutment 1 with all the formwork removed. The steps visible in the top of this section of the abutment are bearing seats. Each seat will accept one girder. The varied levels of seats create and define the drainage cross-slope of the roadway deck above.
Pier Cap Construction - with the pier columns complete work to shore, form and pour the pier caps was begun. The pier cap connects the columns and provides the seat for the bridge girders to bear upon. Once both piers caps are finished the contractor will be able to move on to the major task of placing the concrete beams or girders which are almost 100 feet long and 4 feet deep. These concrete girders have been formed and poured or cast in an off site yard. This is known as pre-casting. The girders will have to be transported to the building site on trucks.
Workers assemble temporary bracing called shoring which will support the formwork used to contain the wet concrete for the pier caps.		Chuck Snider and Lawrence Super mark the center locations of the seat for each girder at the top of the pier cap on the . Surveyors will set the correct elevations.
Bundles of pre-shaped reinforcing steel is placed on the shoring. One side of the pier cap forms are visible to the right with surveyed markings indicating the final stepped shape of the girder seats.		Worker tying rebar for the pier cap. When the steel is in place the second side and the ends of the form will be added.
Pier cap forms and reinforcing steel nearly ready for concrete. The steel used in the pier caps is all epoxy coated to inhibit rust.		Concrete trucks arrive with concrete.
A crane and bucket delivers fresh concrete to workers atop the pier cap forms.		As concrete is delivered workers again use a large vibrator to settle out air pockets and fill all the corners in the forms.




Construction to November 4, 2003 Abutment Walls Construction - workers level the earth at the bottoms of the abutment wall forms, place the reinforcing steel and fill the forms with concrete. This work will complete this portion of construction for Abutment 4, the North Abutment. The next stage of abutment construction will not occur until after the bridge girders are set in place.
The soil under the abutment wall is leveled and compacted as this ground will act as the bottom of the abutment form.		Thin sheets of galvanized steel are used to create a slipping non-positive connection between the wingwall pile cap and the wingwall above to better accommodate the type of forces that will effect the completed abutment.
The reinforcing steel assembly for the abutments are much larger than caissons and are usually tied in place. The front of the form will not be constructed until the steel is placed to allow access. Notice the tops of the abutment piling visible between the steel bars.		With the steel complete and the front of the form erected workers begin to fill the abutment form with concrete just as they did to complete the pier columns.
Since the abutment wall is shallow but very long, a large vibrator is used to ensure that the concrete reaches the bottom of the form and fills evenly without voids. The long black tube powers the long metal vibrator wand that disappears inside the form in this photograph.		The abutment is becoming a recognizable shape with the wingwall forms visible in the background. Workers in the foreground trowel the smooth surface where the bridge beams or girders will soon be placed.




Pier Column Construction - with deep foundations (Caissons) for the piers completed construction of the actual pier columns can begin above grade.
Reinforcing steel cages assembled earlier, are lifted into place on top of the pier caissons. The column steel has a green epoxy coating to inhibit rust that is not required in the caisson steel. There are three columns for each of the two piers.		The column steel is fastened or tied to the projecting caisson steel. The caisson steel was left with specific length overlaps to ensure a sound connection with predictable characteristics.
Once the reinforcing steel is placed workers construct a temporary mold known as a form. The form is constructed of wood and steel and made to the size and shape of the column. The form must be strong enough to contain the wet concrete until it hardens or sets.		CDOT inspectors test the concrete prior to approving it for use in the columns. See the photo captions for Caisson Construction below.
A funnel attached to a large flexible hose known as a tremie is settled over the top of the column form. The hose is long enough to reach to the bottom of the forms.		Concrete is delivered to the column form in buckets and dropped through the tremie. The tremie hose ensures that the concrete fills the form from the bottom up continuously and without voids.
As the form is filled the tremie is gradually withdrawn. When the form is full the tremie is moved to the next column form.




Construction to October 19, 2003 Pile Caps Construction - with the deep foundations (pilings and caissons) nearly finished, the Contractor is beginning to place pile caps. These are large slabs of poured-in-place steel reinforced concrete, which provide the base for the above ground structures. This will include the pier columns and pier caps, abutments, wingwalls, pedestals and the pedestrian overlooks.
A view looking North down the centerline of the SH 12 Bridge. Pilings for the North Abutment, which are yet to be trimmed to the correct elevation, are visible across the Purgatoire River and the steel cages of six completed caissons (three per pier) can be seen in the foreground.		This is the completed formwork for the back inside of the forms that will be used to pour the concrete for the North Abutment. Note that the pilings are now cut to the proper height to be embedded into the abutment.
This is a form for one of the larger pile caps. The pile cap will support the pedestals at the sides of each abutment. Note that the black reinforcing steel (used below grade) is already in place.		A completed pedestal pile cap. The various foundations are kept separate to account for the different types of movement that each element of the bridge will encounter. Similar caps will support the ends of the wingwalls and the pedestrian overlooks.




Construction to October 15, 2003 Placing the Pilings - the abutments and wingwalls or end supports of the Purgatoire River Bridge are founded on long steel pilings that are driven into the ground until they hit bedrock.
Steel pilings are set at each location with the aid of survey equipment so they align accurately with the structure to be built above.		Piles are then driven into the ground with a giant hammer or pile driver. As the first length of pile disappears into the ground, a new length of steel pile is welded or spliced to the end and the driving continues at each of the locations.
Driving continues until the tip of the pile reaches bedrock. When the pile can be driven only 1 inch in every 10 blows of the hammer the pile has reached refusal. Each pile is checked in this way to ensure that it rests deep in the bedrock.		All pilings are driven to refusal at all of the abutment locations. They now need to be cut to length.
With the aid of a surveyor the piles are cut to length. This is important to ensure that each pile will embed the proper distance into the concrete pile cap and abutment to be placed above.
Caisson Construction - Conditions that occur near the river require a deep foundation, which is different from that of the abutments and wingwalls. The piers or intermediate supports of the Purgatoire River Bridge are founded on concrete caissons. Concrete caissons are essentially concrete columns constructed all the way to bedrock.
Workers tie individual pieces of reinforcing steel into an assembly known as a cage. The cage will be lowered into a 42 inch diameter hole or shaft drilled several feet into bedrock. There are three caissons for each pier of the bridge.		The finished reinforcing cage is lifted for placement in the shaft. The shaft is created by a large drilling machine and is protected from cave-ins by a large sectional steel tube or sleeve that is extracted as the concrete is poured into the shaft.
Workers tie reinforcing steel for the pier columns that will be constructed above and embedded into each caisson. The pier columns are above ground and more exposed to corrosive elements so the steel is epoxy coated and appearing green instead of grey. The coating will help prevent rust on the steel thus preventing damage to the concrete.		CDOT inspectors are testing the concrete that will be used to fill the caissons. A metal cone is filled with sample taken from each truck that is delivered to the site. The cone is then inverted to dump the concrete onto a plate. Depending on how the concrete holds its shape or slumps it can be determined if too much or too little water is present. This is called a slump test. The results are recorded in inches.




Construction to early October 2003 The 6th week of the Phase One construction. Clearing and Grubbing - the Contractor's first task is preparing the construction site. Plants, trees, trash and old construction debris are removed. Trees that are not directly in the path of the project are preserved and are clearly marked if they are close to construction activity.
The general limits and easements of proposed project are marked with stakes by surveyors.		Constructors remove and dispose of any vegetation and debris within the limits of either the construction or easement areas.
Cleared ground ready for placement of substructure elements.