North Shore Road Bridge Retaining Wall Improvements

During a summer 2021 inspection, the City discovered cracks and movement in the retaining wall on the east side of the northern approach to the North Shore Road Bridge, which supports the approaching roadway. To maintain public safety, the bridge has remained closed to all vehicular traffic since summer 2021.

The City has contracted with DOWL for design services and Emery and Sons for construction services under a Construction Manager/General Contractor project delivery approach. Construction on the retaining wall replacement is expected to begin in fall 2022. 

Project Updates

September 23, 2022

Construction on the retaining wall replacement is expected to start in early October and be complete in early spring 2023. 

Key information:

  • Crews and equipment will begin mobilizing to the site and working on utilities the week of October 3. During this preliminary work, pedestrians and bikes should expect intermittent daytime closures of the bridge.
  • Starting the week of October 17, the bridge and roadway will be temporarily closed to ALL traffic 24/7. This includes people walking, rolling, riding, driving and boating. This area will be an active work zone and unsafe for the public to access.
  • There will be no boat access into or out of Lakewood Bay. Passage under the bridge will be blocked as crews will be dewatering the work zone around the bridge and walls.
  • Lakewood Bay will be partially lowered several feet to enable a safe work zone. If you store your boat on a lift for the winter in Lakewood Bay, it should be secured and on the lift by October 17. If you don’t have a lift, your boat needs to be removed by October 15. That is the last day the marina is open prior to October 17.
  • There will be no parking on the south side of the bridge. Crews will be staging equipment in the right-of-way.
  • Work hours are Monday to Friday, 7 a.m. – 6 p.m. and Saturday 8 a.m. – 5 p.m. During work hours, please expect an increase in noise and truck traffic as excavators and dump trucks will be accessing the site.

Schedules are subject to change. 

September 2, 2022

Major construction is expected to begin in mid-October. 

 Key information: 

  • Crews and equipment will begin mobilizing to the site in early October. Construction is expected to be complete in four-five months (first quarter of 2023). 
  • To maintain safety, starting in mid-October, the bridge and roadway will be temporarily closed to ALL traffic. This includes boats, pedestrians, bikes, and vehicles. This will be an active work zone and unsafe for the public to access.
  • There will be no boat access under the bridge in to or out of Lakewood Bay. Passage under the bridge will be blocked as crews will be dewatering the work zone around the bridge and walls.
  • Lakewood Bay will be blocked off and the water will be partially lowered by several feet. Oswego Lake (west of the bridge) is not anticipated to be drained/lowered. 
  • If you own or house a boat in Lakewood Bay, please remove it by October 17. 
  • Boat access will be open once construction is complete.
  • There will be no public parking on the south side of the bridge. Crews will be staging equipment in the public right-of-way.
  • Work hours are Monday to Friday, 7 a.m. – 7 p.m. and Saturday 8 a.m. – 5 p.m. During work hours, please expect an increase in noise and truck traffic as excavators and dump trucks will be accessing the site.

Details on the railing aesthetics will be shared shortly. The design of the railing is expected to incorporate a similar look to the South Shore Road bridge railing. 

March 30, 2022

This week, the contractor mobilized to the North Shore Road retaining wall work site, to start setting up the bladder bags for dewatering the work zone around the bridge. Upon deployment, the contractor discovered pockets of the lake bed that were deeper than originally anticipated. This has pushed the dewatering bags out of the depth of their safe operating condition.

The initial survey that was conducted in the design stage did not catch some of the lower points in the lake. This was unforeseen and a localized issue that was discovered this week by the contractor.

Out of an abundance of caution, we are deferring this work until the water level can be lowered to a safe operating level for crews.

We plan to resume the repair later this fall, when we can lower the water levels in the lake slightly enough so it is safe to resume work.  Coordination with the Lake Corp will be on-going.

Pedestrian, boat and bike access to the bridge will be restored as soon as possible, but the roadway and bridge will remain closed to vehicular traffic until the work can resume this fall.

March 21, 2022

Considering the feedback received from the March 16 community meeting, the project team has since reviewed the schedule, confirmed availability of labor and materials, and has developed contingency plans. The City is proceeding with construction of the wall replacement this spring, instead of waiting until later this fall. Safety is our number one priority.

 Key information: 

  • Crews and equipment will begin mobilizing to the site the week of March 28. Construction is expected to be complete by late spring.  
  • To maintain safety, starting the week of March 28, the bridge and roadway will be temporarily closed to ALL traffic. This includes boats, pedestrians, bikes, and vehicles. This will be an active work zone and unsafe for the public to access.
  • There will be no boat access under the bridge in to or out of Lakewood Bay. Passage under the bridge will be blocked as crews will be dewatering the work zone around the bridge and walls.
  • Boat access will be open by mid-May, if not sooner, and open for the summer months.
  • Pedestrian access will be open for the June Lake Run.
  • There will be no public parking on the south side of the bridge. Crews will be staging equipment in the public right-of-way.
  • Work hours are Monday to Friday, 7 a.m. – 7 p.m. and Saturday 8 a.m. – 5 p.m. During work hours, please expect an increase in noise and truck traffic as excavators and dump trucks will be accessing the site.

March 18, 2022

On March 16, the City held a community meeting with residents to share more about the project and what to expect during upcoming construction; particularly related to boat, pedestrian, vehicle and bike access.

An audio recording of the meeting can be found here.  

March 10, 2022

  • Construction is expected to start in late March/early April, and be complete by late spring.
  • To maintain safety, the bridge and roadway will be closed to ALL traffic. This includes boats, pedestrians, bikes, and vehicles. This will be an active work zone and unsafe for the public to access. Please use alternate routes.
  • There will be no boat access under the bridge into or out of Lakewood Bay. Passage under the bridge will be blocked as crews will be dewatering the work zone around the bridge and walls.
  • During work hours, please expect an increase in noise and truck traffic as equipment including excavators and dump trucks will be accessing the site.

Schedule Commitments

  • We will commit to having boat access open by mid-May and open for the summer months. 
  • A final go/no-go decision on whether to proceed with construction this spring will be made a few days before construction starts. Information will be posted on the project website.
  • If needed, we will delay the work to start in the fall of 2022, after the summer boating season.

March 7, 2022

Currently, the bridge and roadway remain closed to vehicular traffic only. To maintain safety, during construction, the bridge and roadway will be closed to ALL traffic: including boats, pedestrians, bikes, and vehicles. There will be no boat access under the bridge into Lakewood Bay.

More information will be shared the week of March 14, 2022.

December 16, 2021

Project team staff will be presenting an update to City Council on Tuesday, December 21, 2021. View the council report and recommended actions. 

Frequently Asked Questions 

[updated September 22, 2022]

Construction Schedule 

When is construction expected to start?

Crews and equipment are expected to begin work in fall 2022 and be complete in early spring 2023. 

What is the plan for construction?

A work zone will be set up on the lake around the bridge, and water will be removed from the work area. Barriers (a port-a-dam) will be placed in Half Moon Bay near the bridge to isolate the work area and Lakewood Bay from the main lake. Lakewood Bay will be partially lowered. This will create a safe and dry area for the crews to begin excavating, removing the existing retaining walls, and replacing the new walls.

Coordination with Lakecorp is ongoing.

Will the entire lake need to be lowered/drained?

The plan is to partially lower the water levels in Lakewood Bay to create a dry work zone. The main lake is expected to be held at normal levels for the duration of the project.

I store a boat on Lakewood Bay. Do I need to move it?

Yes, the bay will be lowered several feet and will not be usable for up to two months. If you store your boat on a lift for the winter in Lakewood Bay, it should be secured and on the lift by October 17. If you don’t have a lift, your boat needs to be removed by October 15. That is the last day the marina is open prior to October 17. If you have any questions about boat use, please contact the Lakecorp.

During construction, will the bridge be open to people walking, rolling, riding, and boating?

No, to maintain safety, the bridge and roadway will be closed to ALL traffic 24/7. This includes people walking, rolling, riding, driving and boating. This will be an active work zone and unsafe for the public to access. Please use alternate routes.

How will boat access be restricted by construction?

There will be no boat access under the bridge into or out of Lakewood Bay. Passage under the bridge will be temporarily blocked and Lakewood Bay will be partially lowered.

I live in the local area, can’t I travel over the bridge and through the road closure signs?

No, the road closed signs are there for a reason – to keep you safe and vehicles out of the closure area. Please do not attempt to move the barricades or travel past the signs, even if you live in the local area. 

Will my trash or mail service be interrupted?

The City notified Republic Services and USPS about the closure. If you have additional work at your home (landscaping, construction, etc.), please let them know to use an alternate route.

What about emergency vehicle access?

The bridge closure will not impact emergency vehicle access. There will be no interruption to emergency response – Police and Fire will be able to access the area from the north or the south.

Why was the work delayed until fall 2022?

In late March 2022, the contractor mobilized to the North Shore Road retaining wall work site, to start setting up the bladder bags for dewatering the work zone around the bridge. Upon deployment, the contractor discovered pockets of the lake bed that were deeper than originally anticipated. This has pushed the dewatering bags out of the depth of their safe operating condition.

The dewatering bags are not sufficient for the current depth of water, and it would be unsafe to take the risk of putting them in at this time.

Out of an abundance of caution, the City deferred the work until the water level can be lowered to a safe operating level for crews in fall 2022.

How did this occur?

The initial survey that was conducted in the design stage did not catch some of the lower points in the lake. This was unforeseen and a localized issue that was discovered when the contractor mobilized to the site.

Costs

What is the cost of the repair? How is it being funded?

Given this was an emergency situation, the project is not funded in the current budget. However, in December 2021, City Council directed staff to use American Rescue Plan Act funding for the unanticipated expense. The total estimated cost for the project including design, construction, and administration is between $1,000,000 and $1,250,000.

Background

Why has the North Shore Road Bridge been closed since summer 2021?

During a July 2021 inspection, the City discovered cracks and movement in the nearby retaining wall, which supports the approaching roadway. To maintain public safety, the North Shore Road Bridge has remained closed to all vehicular traffic as the City conducted structural analysis of the retaining wall and approaching roadway. There are concerns with the retaining wall and roadway, not the bridge itself.

What did you base your decision for closure on?

The decision to close the retaining wall (and adjacent bridge) was based on visual assessments from geotechnical and structural engineers, and our own field investigations that indicated cracking and movement between the wall and the roadway.

The survey data showed that the NE corner approach of the retaining wall appeared to have moved about an inch in the past two years, and is bowing outward. 

How long will the bridge and road be closed for?

To maintain safety, the bridge and roadway are expected to remain closed until repairs are completed.

How often is the bridge inspected?

As a part of managing our roadways and bridges, the City has routine analysis done on our transportation system. ODOT inspects our bridges typically every other year. The North Shore Road Bridge specifically has been routinely monitored and surveyed since 2014.

Geotechnical Assessment Findings  

What did the structural analysis find?

The design team has performed detailed testing and analysis of the retaining wall and surrounding area to determine the extent of the defects. In late 2021, the project team and City staff explored alternatives and selected a preferred alternative.

The geotechnical and structural findings support replacing the retaining walls on the northeast and northwest approach with Mechanically Stabilized Earth (MSE) type walls. This is an economical solution that should provide structural stability and complement the existing retaining walls on the south side of the bridge.

What will the new retaining wall and handrail look like?

The retaining walls will be replaced with Mechanically Stabilized Earth (MSE) type walls using lock and load components that are 32” x 16”. Below is an example of the blocks to be used for the wall:

A parapet protective wall and handrail will also be installed. The project team is finalizing the aesthetic details of the wall and handrail. The design of the railing is expected to incorporate a similar look to the South Shore Road bridge railing.

Will the bridge also be replaced?

The bridge itself does not appear to be of concern based on the latest bridge inspections performed by DOWL.

 

Project Details
ID: 
WO 324
Year: 
2021
Status: 
Active
Project Contact: 

David Kudna

Project Manager

503-635-0261

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