7th Street Bridge Project
Bridge Plan Sheets
The project started on Tuesday, January 3rd, 2023 and the contractor is currently working on the causeway in the Cedar River.
The contractor has removed the west span truss. From the middle span, the contractor has removed the concrete deck, and approximately 25% of the steel floor beams have been removed. Once United Contractors removes the steel truss from the river, they will continue the work on demoing the east span.
The center truss has been removed. United Contractors continues to build the causeway in the river. They are now building it broader to protect the site encase the water levels rise with the incoming rain and snow this week. The east span has 50% of the concrete removed from the deck. The truss should be removed sometime in the middle of next week. United Contractors plans to start removing the existing piers this week. The soil borings for the drilled shafts are currently in for review. Once the review process is complete, United Contractors will start the drilled shafts.
Due to the heavy rain this past Sunday and Monday, the Cedar has risen over 8 feet. Most of the causeway has washed downstream. United Contactors moved to the west abutment. The existing west abutment has been removed, and United is digging out for the new abutment this morning.
The plan for next week is to start the pile-driving operations for the West abutment. Most of the abutment formwork is built, so it won’t take United long to set the abutment and wing wall forms. The piling rebar was delivered this past Tuesday and Wednesday.
Once the water level drops, United will reconstruct the sand causeway and start the drilled shaft operations. United has tied the rebar for several drilled shaft cages. The rebar is in the yard on the northwest side of the project.
United Contractors poured the lower portion of the west abutment last week. A meeting with United Contractors and MR2 (Drilling Company) was held on-site to discuss the drilled shaft process. MR2 will start mobilizing to the project this week. The plan is to drill the two test shafts and get the report work started once the concrete for both shafts is up to strength.
United Contractors has removed the far east section of the bridge and is currently breaking up the existing east abutment. They hope to remove the last truss later this week or early next week.
As of today, the two demonstration shafts have been installed and tested. The test reports were submitted this past Friday, April 28th. MSA is internally reviewing the two demonstration shaft reports. United Contractors is working on the substructure work. The east abutment was poured last week. While the demonstration shafts are being reviewed, United Contractors will work on filling in the pier areas along the causeway. Once the review is complete, MR2 will return on-site to start the production shafts for Pier 1.
United Contactors planned to start the production shafts this week. Unfortunately, Northern Iowa received 5-7 inches of rain this past weekend. This rain has caused the Cedar River to rise nearly 8 feet. I have attached several pictures detailing the difference from last week to this week. The drilling contractor, MR2, is on-site with their equipment. MR2 plans to start the drilled shaft work next week; however, United Contractors will need to rebuild the causeway around Pier 3 based on how high the water is. The causeway work will take a good portion of next week.
The contractor has poured both abutments and started pouring the wing walls at the West Abutment. The southwest wing wall is complete. The northwest wing wall is scheduled to be poured tomorrow at 9:00 AM. United Contractors has pretied one of the pier caps and is in the process of tying the pier column rebar. The pier cap and pier column templates are built and in the yard.
United Contractors work was delayed by the high water last week. This week, United Contractors and drilling company MR2 started the work for the Pier 3 drilled shafts. MR2 started drilling on Wednesday and finished drilling shaft 4 Thursday early afternoon. Today, MR2 and United Contractors set the steel cage for the drilled shaft and will place concrete, using a pump truck, for pier 3, shaft 4. The drilled shaft work for all four piers should take about a month and a half to two months to complete.
Check back later for more updates!