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.
There has been a lot of progress on-site since the last update. The drilling contractor, DM2, is working on the last drilled shaft for Pier 1. DM2’s subcontractor Terracon was on-site yesterday to do the soil boring for Pier 4. Once the report is submitted and approved, DM2 can continue drilling the remaining 4 drilled shafts. United Contractors is currently using a clam bucket with their crane to move river material to Pier 4. United Contractors set up the Pier 3 column forms yesterday. This morning United Contactors set the scaffolding to hold the column forms in place and adjusted the rebar to meet the project spacing.
Tomorrow, Wednesday, United Contractors will pour the four columns for Pier 3. They can remove the forms on Monday and immediately start the pier cap operations. By the end of next week, one pier will be completely built.
As of today, Piers 2 and 3 are complete. The prime contractor, United Contractors, poured the pier columns for Pier 1 today. DM2 is currently drilling the drilled shafts for Pier 4. Two of the four drilled shafts are complete. DM2 plans to pour the north drilled shaft tomorrow at noon. The drilled shaft work should be complete by mid-week next week.
United Contractors plans to pour the pier cap for Pier 1 on Thursday next week. United Contractors plans to set girders the week of August 21st. The girders should be delivered Thursday and Friday. If anyone is interested in watching United Contractors set the girders, they plan to set the span between Piers 2 and 3 first and then work to the west. I will send an update if the schedule changes.
United Contractors set the second span of beams today!
United Contractors has decked Spans 1 and 2 for the past two weeks. The first span is completely decked, besides the overhangs. The second span is 50% decked as of this morning. United Contractors plans to pour the Pier 4 cap tomorrow. They will use concrete probes in the pier cap to gauge when the concrete will be strong enough for the next set of concrete girders. The next round of concrete girders is scheduled to be delivered on Wednesday, September 13th. This will span over the running water of the Cedar River, Span 4. The rest of the girders will be delivered on Tuesday, September 19th, and the last span will be delivered on September 26th.
If United stays on track, they plan to pour the concrete deck the week of October 9th.
Check back later for more updates!