Piers rising on both sides of river

Construction update

Drilling for footings of Second Street Bridge complete

Crews drilled the last of the 40 foundation shafts for the footings of the Second Street Bridge on Wednesday, Feb. 13. They will pour concrete into the footings the week of Feb. 25, after fabricating and placing the rebar cages that will reinforce the shafts.

Hammering and shoring will generate additional noise

People living and working near the I-35W Bridge construction site will likely notice additional hammering noise from time to time throughout the next few months as crews build the temporary support structures known as “falsework” (see photo, above). These structures will support the forms for the spans of the bridge on each side of the river. This spring, the superstructure will be “cast in place” by pouring concrete into the forms.

Building the support structures involves using cranes to hoist heavy steel components into place and then bolting them together. For the safety of the workers involved in these operations, the heavy lifting is scheduled to take place during the day, with the less complicated bolt work occasionally continuing at night. The hammering is currently taking place on the south side of the river and will continue for about two weeks. Falsework construction will continue for several months with intermittent noise.

Later this week, crews will also begin shoring work for the 40-foot retaining walls that will stand beside the freeway entrance and exit ramps at University Avenue. The shoring operation will involve excavating the area and then placing steel supports in the ground, which will create noise and vibrations in the immediate vicinity. Shoring will take a week or so to complete, after which work on the walls will take place around the clock. Both retaining walls should be complete by early spring.

• pour the first part of the footing for the north abutment, where excavation is currently underway (see photo, above);
• continue work in the casting yard on additional segments for the 504-foot main span (as of late this week, concrete has been poured for five of the 120 segments, and Flatiron soon plans to cast up to one segment a day);
• relocate a water line located between Second Street and the north abutment; and
• move wiring for the traffic signal system at University Avenue and the east frontage road (note that the left lane of University Avenue will be closed between 9 a.m. and 3 p.m. on Monday, Feb. 18, while this work is being done).

Other than viewing what’s happening from the 10th Avenue Bridge, the public is asked to stay away from the bridge construction area for safety reasons. 

The Minnesota Department of Transportation (Mn/DOT) and the Flatiron-Manson construction team intend to build a high quality and safe bridge while minimizing disruptions to the surrounding neighborhoods.

We will continue to distribute updates weekly and welcome your comments on how to improve the communication process between the project team and the community.

For more information on the I-35W project visit www.mndot.gov

This photo, shot on Monday, Feb. 4, shows how the piers are taking shape on both sides of the river for the two parallel bridges (one northbound and one southbound) that will comprise the new St. Anthony Falls (I-35W) Bridge. Since Monday, the forms for Pier 2 northbound (in the foreground) were moved onto the footing (closer to the river) and filled with concrete. After two more pours, Pier 2 will reach its full 70-foot height like Pier 3 southbound across the river in the background. The next pour at Pier 2 is schedule for Monday.

At Pier 4 (above) crews poured concrete for the southbound footing last weekend and have been forming rebar for the northbound columns this week. You’ll see all of the columns come up to their full height in the next couple of weeks.

Just north of Pier 4, to the right of the historic wall shown above, crews have been excavating around Abutment 5, in preparation for pouring the footing there next week.

More segments to be cast in the casting yard

After last week’s successful casting of the first segment for the bridge’s main span, crews poured three more segments this week. The casting process is occurring in three of the four heated sheds in the Casting Yard on the unused section of I-35W just north of Washington Avenue. By the end of the month, all four sheds will be utilized, and crews will cast an average of one segment a day until all 120 are finished.

Note to Minneapolis commuters: Now that the casting process has begun, trucks will frequently need to enter the construction area from Washington Avenue. Although trucks will enter the site by using the on-ramp to I-35W northbound, the ramp remains closed to other motorists. An attendant wearing high-visibility safety gear will be posted at the gate whenever it is open to help direct traffic.

Getting a closer look

Try the touch-screen kiosks at Mill City Museum and the airport - After installing a touch-screen kiosk last week in the lobby at Mill City Museum, project representatives this week set up a second touch-screen kiosk at the Minneapolis-St. Paul International Airport. The two kiosks provide a variety of information about the bridge, including a photo gallery, a timetable and animations showing what the finished bridge will look like from a helicopter, a boat and a car. We appreciate the willingness of Mill City and the Airport to help us get information to the many people who visit their facilities every day.

Visit the website - The website now includes a Virtual Sidewalk Tour with graphics and information on the construction process as well as animations showing the finished bridge from the vantage point of a helicopter, a boat and a car. Visit www.mndot.gov and click on the orange “Virtual Sidewalk Tour” button to view the images. Please also encourage others you know who are interested in the project to go to the site to sign-up for the weekly updates.

Access the webcams – Two webcams are now in place to show what is happening at the construction site. One provides a panoramic view of the entire site, looking east from a rooftop on the north side of the Mississippi River. The other camera is mounted on a light pole on the 10^th Avenue Bridge and will provide periodic close-ups on construction activities. To see the webcam views, visit the project website at www.mndot.gov.

Tune in to WCCO - The project continues to draw lots of local and national media attention. Popular Mechanics and “Nova” both sent camera crews to the site this week. On Monday, Feb. 11, Jon Chiglo, Mn/DOT Project Manager, will be interviewed on WCCO-AM radio at 7:10 a.m.- tune in for the latest information.

Attend a Sidewalk Superintendent Talk – Over 100 people showed up for the Sidewalk Superintendent Talk last Saturday, setting a new attendance record. These weekly events provide an opportunity to accompany project representatives on a walk across the 10^th Avenue Bridge, where you can see the construction workers in action and ask questions about the project. If you’d like to participate, meet in the parking lot in front of Grandma’s restaurant at 19^th and Washington Avenues by 11 a.m. on any Saturday.

Take a self-guided tour - Signs describing the design/build process are mounted along the 10th Avenue Bridge.

Call the hotline - If you have any questions about the project, please call the hotline at 612-236-6901 between 7 a.m. and 8 p.m. daily. Messages left after 8 p.m. will be returned first thing the next morning.

Request a presentation - Representatives of Mn/DOT and Flatiron-Manson are willing and eager to provide project updates to neighborhood associations, business associations, and other groups. To arrange a presentation, please call the hotline, 612-236-6901.

Other than viewing what’s happening from the 10th Avenue Bridge, the public is asked to stay away from the bridge construction area for safety reasons. 

The Minnesota Department of Transportation (Mn/DOT) and the Flatiron-Manson construction team intend to build a high quality and safe bridge while minimizing disruptions to the surrounding neighborhoods.

We will continue to distribute updates weekly and welcome your comments on how to improve the communication process between the project team and the community.