DATE:
December 12, 2023
CATEGORY:
Consent
DEPT.:
Public Works
TITLE: Sleeper Avenue Bridge Repair,
Project 23-39—Various Actions
RECOMMENDATION
1. Find that in accordance with California Environmental Quality Act requirements, Sleeper Avenue Bridge Repair, Project 23 -39, is categorically exempt as Class 1, Existing Facilities, under California Public Resources Code Section 15301.
2. Transfer and appropriate $300,000 from the Construction and Conveyance Tax Fund to 2022/23 City Bridges and Culverts Structural Inspection and Repairs, Project 23 -39, increasing the project budget from $220,000 to $520,000. (Five votes required)
3. Approve plans and specifications for the Sleeper Avenue Bridge Repair Project and authorize staff to advertise the projects for bids.
4. Authorize the City Manager or designee to award a construction contract to the lowest responsible responsive bidder if the low bid is within the project budget of $520,000.
BACKGROUND
As a part of the Stevens Creek trail system, the Sleeper Avenue bridge (see Figure 1) is used by recreational trail users, commuters, and students who need to cross Stevens Creek. In 2018, an irrigation pipe below the bridge broke and eroded a section of the eastern creek bank below the bridge deck. Staff has been monitoring the creek bank and observed from the storms in early 2023 that the erosion expanded and exposed the upper portion of the br idge foundation ( see Figure 2).
Sleeper Avenue Bridge Repair, Project 23-39—Various Actions December 12, 2023
Figure 1: Project Location
Figure 2: Sleeper Avenue Bridge Bank Erosion
Sleeper Avenue Bridge Repair, Project 23-39—Various Actions December 12, 2023
On September 8, 2022, the City issued a Request for Proposals for bridge inspection and design services for 2020/21 City Bridges and Culverts Structural Inspection and Repairs, Project 21 -52.
Biggs Cardosa Associates, Inc. (Biggs Cardosa), was selected as the most qualified firm to provide the bridge inspection and design services. Due to the observed creek embankment erosion and potential bridge stability risks for the Sleeper Avenue bridge, the City engaged Biggs Cardosa to conduct a bridge assessment in spring 2023. The assessment concluded that the bridge was stable and can remain open to the public unless erosion progresse d to a point that the bridge would have to be closed . In response, staff developed and implemented a monitoring plan for the bridge and prepared a contingency bridge closure plan for detouring trail users should it be needed.
On June 13, 2023 , the City executed an agreement with Biggs Cardosa to provide professional design and construction support services to repair the Sleeper Avenue bridge for a total not-to- exceed amount of $98,000.
ANALYSIS
Biggs C ardosa developed a bridge structural repair plan to provide additional support to the bridge foundation and to hydroseed the eroded bank (see Figure 3). The project will retrofit the abutment to install an aluminum waler, anchor rod, and sheet pile anchor to mitigate bank erosion issues and loss of lateral support. The sheet pile anchor will be installed underground in the open space between the top of the creek bank and Stevens Creek Trail. The construction work will take place above the creek bank, and the contractor can access the pile cap foundation from the bridge deck.
Figure 3: Sleeper Avenue Bridge Repair Plan
Sleeper Avenue Bridge Repair, Project 23-39—Various Actions December 12, 2023
The plans and specifications for the project are completed and ready to advertise for bids. Staff anticipates the construction will take approximately four weeks to complete. The Stevens Creek Trail and the Sleeper Avenue bridge will remain open during the majority of the construction time frame; however, certain areas of the trail and the bridge will be fenced off to provide space for construction activities. It is anticipated that the contractor will need to close the Sleeper Avenue bridge for at least one weekend to install the aluminum waler and complete other necessary work on the pile cap. Closure over the weekend was selected to minimize impacts to students and commuters. Advance notice of the closure will be provided, and a detour plan will be in place for trail users who typically access the trail via the Sleeper Avenue bridge. Once the contractor begins work in early 2024, a more definitive schedule for the construction activities and bridge closure will become available.
If the recommended actions are approved and a responsive bid from a responsible contractor within the project budget is received, construction is anticipated to begin in early 2024 and complete in about two months.
The design and construction costs for Sleeper Avenue Bridge Repair are estimated to be $300,000 (see Table 1). It is recommended to fund this project as part of 2022/23 City Bridges and Culverts Structural Inspection and Repairs, Project 23 -39, which provides funding for construction and repairs of deficiencies of City -owned vehicular and pedestrian bridges, culverts, tunnels , and observation decks. However, Project 23-39’s current budget is only $220,000 , and this funding will be needed for any other bridge repairs identified in the Citywide bridge inspection currently under way. Therefore, staff recommends adding $300,000 to Project 23-39 to fund the Sleeper Avenue bridge repair costs, increasing Project 23-39’s budget to $520,000.
Table 1: Sleeper Avenue Bridge Report Cost
Construction $100,000
Construction Contingency 15,000
Project Management 15,000
City Construction Management and Special Inspection 30,000 Consulting Services 120,000
Printing and Other Miscellaneous Costs 2,000
Subtotal $282,000
City Administration 18,000
Project Cost $300,000
Sleeper Avenue Bridge Repair, Project 23-39—Various Actions December 12, 2023
Community Outreach
Due to the heavy use of the Sleeper Avenue bridge, staff has prepared an extensive outreach plan to notify the community about the construction project, schedule, impacts, and detour. A webpage has been created at www.mountainview.gov/cityprojects which the public can visit for project updates. Notifications and project updates will also be posted on the Community Services Department webpages, provided through the City of Mountain View’s social media channels, and sent to neighborhood associations, local schools, and stakeholder groups , such as Friends of Stevens Creek Trail. Physical signs will be posted at Sleeper Park, along Stevens Creek Trail, and along streets leading to the Sleeper Avenue bridge.
Environmental Clearance
In accordance with the California Environmental Quality Act (CEQA), staff has reviewed the scope of this project and determined that it meets the classification for categorically exempt as Class 1, Existing Facilities. The project site is an existing bridge, and the proposed work is to repair the existing bridge foundation due to erosion damage . Staff recommends that Council make the finding that in accordance with CEQA requirements, the project is categorically exempt as a Class 1, Existing Facilities, under CEQA Guidelines (Title 14, Division 6, Chapter 3 of the California Code of Regulations) Section 15301.
FISCAL IMPACT
2022/23 City Bridges and Culverts Structural Inspection and Repairs, Project 23-39, is funded with $220,000 from the City’s Construction and Conveyance Tax fund. Staff recommends appropriating an additional $ 300,000 from the Construction and Conveyance Tax fund to 2022/23 City Bridges and Culverts Structural Inspection and Repairs, Project 23 -39, for a total project budget of $ 520,000, to fund Sleeper Avenue Bridge Repairs in addition to other bridge repairs that may be needed Citywide. There is sufficient balance in the Construction and Conveyance Tax fund for the recommended appropriation.
CONCLUSION
The design documents are complete d for the Sleeper Avenue Bridge Repair project, and the project is ready for construction bidding. The project will repair the bridge foundation to ensure this pathway remains open for the many commuters, students, and trail users who rely on the bridge for travel . If the recommended actions are approved and a responsive bid from a responsible contractor within the project budget is received, construction is expected to begin in early 2024 and be completed in about two months.
Sleeper Avenue Bridge Repair, Project 23-39—Various Actions December 12, 2023
ALTERNATIVES
1. Defer construction and continue to monitor the bridge condition, closing the bridge if the erosion progresses.
2. Provide other direction.
PUBLIC NOTICING
In addition to agenda posting, project notices were sent to stakeholders, including neighborhood associations in the area, organizations with an interest in Stevens Creek Trail use, and properties within a 750’ radius of the Sleeper Avenue bridge.
Prepared by:
Raymond Wong
Senior Civil Engineer
Reviewed by:
Lisa Au
Assistant Public Works Director
Approved by:
Dawn S. Cameron
Public Works Director
Audrey Seymour Ramberg
Assistant City Manager
RW/LL/6/CAM
931-12-12-23CR
203637