Bridge Deck Curing

Teichert Construction completed the intial curing of last week's bridge deck pour this week. This operation was followed by tensioning of the bridge itself. Steel tendons were installed in longitudinal ducts within the bridge structure. Once these tendons were secured and anchored at one end of the bridge, a load was applied from the other side of the bridge to tension the structure. After jacking to the required load, the force in the tendon is transfered from the jack to the end of the anchorage. Prior to it's release from the jack, the tendon is secured by wedges and then the protruding tendon strands can be cut off. This post tensioning operation minimizes the stresses on the bridge from it's own concrete load and eliminates potential cracking to produce a more durable concrete bridge.

The bridge deck is finally exposed after curing under wet burleen blankets for a week.

A hydraulic ram jack is placed over a steel tendon prior to tensioning.

Teichert Construction cuts the protruding tendon strands after completion of tensioning operations.

Soil Nail Wall 7 Operations

After excavating for the first lift of soil nails for Wall 7, Teichert Construction began the process of installing soil nails, steel reinforcement, and shotcrete to form the structural wall itself. This sequencing of work typically takes at least a week from start to finish (excavation, drilling, nail installation and grouting, steel reinforcement, and then shotcrete). County Inspection staff perform onsite inspection of the complete operation to ensure that the proper design specifications are achieved. Inspectors are responsible to verify that the contractor excavates the hillside to the surveyed limits, confirm that soil nails are installed and grouted to the designed lengths, and ensure that the proper reinforcing steel is placed and shotcrete is applied properly.

After excavation, soil nails (40 to 50 ft in length) are installed.

Geocomposite drains ("black strips") are evenly spaced along the cut face.

Prior to shotcrete facing, reinforcing steel mesh and rebar are installed.

An initial layer of shotcrete is applied to the prepared wall face.

Shotcrete is uniformed applied until the design thickness is achieved.

Brushy Creek Bridge Deck Pour

Last week, Teichert Construction completed the deck pour of the Brushy Creek bridge, a milestone event. The concrete deck pour took place at 4 am to minimize the affects of the wind and heat on the concrete itself. Conducting the deck pour prior to the morning commute hours also minimizes the travel time for concrete trucks transporting the material from the plant to the project site. Prior to the deck pour itself, a bidwell was installed on temporary railings supported by the deck forms. Traveling above the deck on rails, the bidwell evenly spreads the concrete (pumped onto the deck in separate operation) to create the final road surface. The temporary rail system and bidwell ensure that the final deck grades are constructed to the designed road grades.

Teichert Construction spreads the concrete prior to the bidwell screeding the concrete to the deck grade

The bidwell passes over the concrete. The auger in the front collects and spreads the concrete while the roller and finish pads ensure the correct grade is formed.

Concrete is pumped directly onto the deck in advance of the bidwell.

After the bidwell passes over the concrete, finishers spray curing compound from a catwalk.

County Inspection Staff test the concrete material properties onsite to ensure quality assurance.

Soil Nail Wall 7 Excavation

Teichert Construction began excavation operations last week for Soil Nail Wall 7, located at the northern project limit. The existing hillside excavation consists of removing occasional sandstone and cemented rock formations. In addition to excavators and blade equipment, Teichert Construction is using breakers to chip and remove the bedrock material. After each "lift" is excavated, soil nails are installed to secure the hillside followed by the shotcrete wall facing.

Teichert Construction excavates the hillside for the initial wall lift.

Exposed rock within the soil strata along the hillside cut face.

Teichert Construction uses a breaker to remove sandstone along the cut face.

Installed soil nails along Soil Nail Wall 7.

Soldier Pile Wall Work Continues

Teichert Construction has completed a signifcant portion of the soldier pile retaining walls required for the road widening at the southern project limit. Steel piles were installed and cast in concrete holes along the hillside. Teichert Construction crews then excavated the hillside and installed timber lagging to retain the hillside slope. A concrete facing wall be installed in front of the timber wall with an architectural finish in the following months.

Teichert Construction removes "lean" concrete and soil around the piles to install timber lagging.

Southbound view of the Soil Nail Wall 2.

Bridge Work Continues

In the last month, Teichert Construction has made significant process in completing the construction of the Brushy Creek bridge widening. Wood form work for the bridge structure was erected and steel reinforcing bars installed. The "stems and soffit" of the bridge structure was poured with only the main deck pour remaining.

Teichert Construction erects forms for the "stems" that come up from the bottom of the bridge (soffit).

Reinforcing steel bars and installed for the stem and soffit.

Northbound view of the bridge widening.

Completion of concrete "stem & soffit" pour.

Soil Nail Wall 4 Production Nail Installation Begins

After completion of verification nail testing and waiting for the proper soil nail materials to be delivered, Teichert Construction began installation of production nails at the Soil Nail Wall 4. The results of verification nail testing confirmed the appropriate soil nail lengths as well as allowed for a redesign of the nail layout for ease of construction. Six inch diameter holes are drilled into the hillside to design lengths prior to installation of the actual steel nail. Grouting of the nail must take place immediately after drilling to prevent cave-ins. Wire mesh and steel reinforcement are then installed along the soil cut face prior to the installation of the shotcrete wall facing.

Installed soil nails along with the Soil Nail Wall 4 cut face extend outward. The black geocomposite drain strips are installed against the soil and will be extended down as each soil nail lift is excavated.

Reinforcing steel bars extend above the cut face to eventually support the extension of a concrete cantilever wall.

Shotcrete installation operation at Soil Nail Wall 4.

A soil nail extends through the reinforcing steel, wire mesh, and initial layer of shotcrete.

Soldier Pile Wall 2 Work Begins

Teichert Construction began construction of Soldier Pile Wall 2 at the southern project limit. Besides the use of soil nails to secure the hillside along Vasco Rd, soldier pile wall retaining systems will be used to stabilize the minor hillside cuts. Approximately 20 to 30 ft deep holes are drilled to accommodate concrete cast in place steel piles. Timber lagging will be installed in between the steel piles prior to the final concrete facing wall. Upon completion Soldier Pile Wall 2 will be approximately 12 ft tall at the highest location.

Drilling rig staged at Soldier Pile Wall 2 location.

Drilling down to pile tip elevation.

Steel pile secured in the proper location prior to concrete pour.

Brushy Creek Bridge Abutments Complete

Teichert Construction completed the Brushy Creek Bridge abutments by pouring them in early August. The abutments secure the bridge structure itself to the footing foundation. Steel reinforcement extends from the footing up into the abutment, which will eventually connect to the bridge deck.

View of Abutment 1.

Falsework installation at Abutment 2.

Laying out falsework girders at Abutment 1.

Brushy Creek Bridge Abutment Work Begins

Earlier this past week, Teichert Construction completed the Brushy Creek Bridge concrete footing pour. Upon completion of this operation, construction workers stripped the wooden forms to expose the concrete footing and began erecting the abutment forms. As this operation proceeds, one can visualize the bridge structure itself as the foundation begins to come up. Reinforcing steel (vertical bars) were installed in the footing to extend up into the abutments to secure the bridge to the footing foundation.

Stripping the footing forms at Abutment 2.

View of Abutment 2 footing (foreground) with Abutment 1 forms in the distance.

Abutment 1 forms being erected.