Bridge work will create noise on the north side next week

The next phase of construction at the I-35W Bridge site will involve installing some steel supports (H-piles) on the north side, which will generate noise and vibrations in the immediate vicinity for about three days next week. Crews need to install H-piles for the excavation of one of the 40-foot retaining walls that will stand beside the freeway entrance and exit ramps at University Avenue. The installation procedure will involve drilling or vibrating, which is different from — and much less disruptive than — the pile driving that was done at Abutment 1 in November.

Starting next week, crews will also be operating a concrete crusher, which will break up the pieces of the old roadway so that they can be recycled and used for the base of the rebuilt I-35W roadway. While the crusher is in use, additional noise — including a loud, steady hum and back-up alarms — will be noticeable. This work will take approximately a week to complete.

Both pile installation and concrete crushing will only occur between 7 a.m. and 6 p.m. Monday through Saturday.

Construction Update

Crews removed the steel forms from Pier 3 southbound over the weekend, revealing the first look at the arched concrete columns inside (see photo above). Since it was too cold to leave the columns exposed to the harsh winter air, crews immediately wrapped them in insulating blankets. When the concrete cures more completely and the weather warms up, the blankets can be removed.

Another Milestone — Last Footing Complete

The footing at Pier 3 northbound was completed this week, which was the last footing for the main bridge. This is a significant milestone because the main bridge is now officially “out of the ground.”

Other progress this week:

• pouring the top sections (or “lifts”) of two columns at Pier 4 southbound; and
• pouring three pre-cast segments in the casting yard, bringing the total number of completed segments to seven of the 120 needed for the main span.

• approximately one-third of the 48,700 cubic yards of concrete needed for the bridge has been poured (the photo above shows an operator in the control room at the Cemstone plant in Minneapolis, one of the two local Cemstone plants supplying all of the concrete for the bridge);
• approximately 400 of the projected 650 workers needed to build the bridge are now on the job;
• workers logged more than 41,000 man hours on the project in February, up from 22,065 hours in January.

 Work scheduled the week of March 3 includes:

• pouring the top lift of the columns at Pier 2 southbound;
• placing rebar in the forms for the side spans on the south side;
• building the supports for the side spans on the north side;
• pouring the first two lifts of the columns at Pier 3 northbound; and
• pouring the top lift of one of the columns at Pier 4 southbound.