duck bay road upper pier repair

Public Works Department Report No. PW-2015-41 1 April 8, 2015

STAFF REPORT Department/Function: Public Works Department Chair: Councillor Jim Crawford Meeting Date: April 8, 2015 Report No.: PW-2015-41 Report Title: Duck Bay Bridge Upper Pier

Refurbishment RECOMMENDATION: It is recommended that the report PW-2015-41 pertaining to the Duck Bay Bridge upper pier refurbishment be accepted; And that Council approves the quotation for Concrete Pier Encapsulation from McPherson Andrews Contracting in the amount of $169,473 before HST; And that the Director of Public Works authority to approve the second part of the upper pier refurbishment if it is within the $75,000 contract contingency; And that the additional funding required will be the balance of the gas tax funding, $42,151, and the remainder added to the long term debt to be taken out for this project, to be confirmed by Council following project completion. INTRODUCTION/BACKGROUND: The Duck Bay Bridge project is divided into two phases. The first phase was to address the piers and the second phase was to replace the superstructure. Included in the first phase was encapsulation of the lower piers (rock filled timber cribs) and surface patching of the upper piers (concrete) to minimize further deterioration.


During the work on the lower pier section the contractor, McPherson Andrews Contracting (MAC), has advised of the concern that there is severe cracking on the bearing plates which is where the truss on the superstructure transfers the load to the piers. The piers were originally constructed without the use of rebar which helps concrete with tensile loading, which would support drilling operations. The patching work that was proposed for the upper pier section would include drilling into upper pier section, installing dowels to support the patch work and then the patching. MAC’s concern is when they begin to drill into the upper pier section near the bearing plate the mass of concrete could break off forcing an emergency road closure as the superstructure would no longer be supported. The Township requested CC Tatham (CCTA) to reevaluate the upper pier section and make recommendations on the necessary repairs. ANALYSIS: CCTA has completed a review of the upper piers, their report is attached. During the initial investigation prior to tendering the first phase (lower pier section) in 2013 only 10 percent of the upper pier required attention. That quantity was included in the tender of the first phase with a value of $13,300. After recently completing the investigation of the upper piers, 75 percent of the upper section now requires attention. CCTA has recommended a full encapsulation of both piers because the amount of patching is significant. Patching versus Full Encapsulating Patching is a temporary repair with a life cycle of 15 years and with additional quantities has an impact of $55,965.50 extra to this phase; this is the cheaper solution but is only a temporary repair. After the patching fix has failed in 15 years a full encapsulation would be required. Patching would be a good solution if we only had a usable life of the bridge structure less than that of the patching. Full Encapsulating (FE) is a long term repair with a life cycle of 30-40 years on this bridge structure at its current use. FE has an impact of $156,173 extra to this phase but when doing life cycle comparisons this option ends up being more cost effective. Completing this work now would match the anticipated life expectancy of the superstructure of 50 years.


Some minor patch work is expected to the upper pier sections nearing the 40 year mark which would extend it to the 50 year life of the superstructure, FE would make any future patching easier as it would be more compatible with modern construction practices. In addition, FE eliminates the possibility of an emergency bridge closure. The expected time to complete the FE is 25 days. CCTA has completed a sketch and details of the work, then submitted it to MAC as part of (Request For Quotation) RFQ No.1 Concrete Pier Encapsulation. RFQ No.1 Concrete Pier Encapsulation only addresses encapsulating up to the underside of the bearing plates; this was decided to avoid working around the bearing plates in case of a mass concrete failure, an emergency road closure would be needed in that case. The bearing plates will require a FE but will be completed once the old bridge is removed during the second phase, dividing the work into two parts this way will improve the quality as there will be fewer concerns when the bridge structure is off making the bearing plates more accessible and larger amounts of delaminating concrete can be removed without concern. Having MAC complete the first part would be beneficial because they are already on site; they have the equipment and people already there to get started so work can be finished in time to avoid disruptions to the boating season. MAC has been a fair contractor to deal with and has the expertise necessary to complete this work. The second part of the FE is expected to be done during the second phase by Owen King Ltd (OKL) once the bridge structure is removed. The tender for the second phase did not include this work or have unit pricing for this type of work so a second RFQ will be submitted to OKL. Since the contract documents have not yet been finalized between the Township and OKL at the time of this report an RFQ can’t be submitted. CCTA has provided an engineer estimate for the second part of the FE which is $35,000. To keep the project moving forward staff is requesting from Council that the Director of Public Works has approval authority on the second RFQ estimated to be about $35,000 for the FE of the bearing plates from OKL. Township staff and CCTA will review the second RFQ and make a recommendation to the Director of Public Works. The contract includes a $75,000 contingency which can accommodate this work. The FE work will require additional work by CCTA for extra site inspections, RFQ preparations and review, drawing preparations and additional administrations. SUSTAINABILITY PLAN: There is no impact to the Sustainability Plan.


FINANCIAL/BUDGET IMPACT: Below is the budget summary from the report of March 11, 2015 dealing with award of the superstructure replacement contract. The “Expected Project Cost” of $1,726,875 forms the basis of the budget that Committee of All Council reviewed on April 7, 2015. The 2015 budget is less than the Expected Project Cost as the money spent in 2014 is not included.

“Project Estimate in February 2014 $2.35 million Construction Cost $143,000 Engineering $2.493 million Original Estimate Actual Budget Approvals $100,000 Engineering 2014 $700,000 Pier Repairs 2014 $1.9 million Superstructure 2015 $2.7 million Approved Budget Actual Project Cost [March 11, 2015] $143,000 Engineering $670,000 Pier Repair $884,008 Superstructure $1,697,008 Expected Project Cost Expected Project Cost including net HST of 1.76% is $1,726,875.”

The current anticipated costs are noted below. Following that is an explanation of the changes. Actual Project Cost [April 8, 2015] $152,500 Engineering $864,919 Pier Repair $919,008 Superstructure $1,936,427 Expected Project Cost

Expected Project Cost including net HST of 1.76% is $1,970,508. The Engineering line has increased to reflect the extra work from CCTA is expected to impact the budget by an additional $9,500. This is related to the additional work for phase 1 and phase 2 to address the various upper pier encapsulation issues. The Pier Repair line has increased for two reasons: 1. due to actual amount of concrete used when filling the voids in the cribbing was significantly greater than anticipated ($38,746); and 2. the encapsulation of the upper


piers ($156,173). It is noted that the changes related to higher water levels were included in the March 11, 2015 numbers. The Superstructure line has been increased by the $35,000 anticipated for the upper pier work in the area of the bearing plates. CONCLUSION: It is recommended that Council choose to fully encapsulate both upper pier section and accept the quotation for Concrete Pier Encapsulation submitted by MAC. MAC is on site and can have the worked completed before boating season and without risk of the bridge being closed due to a bearing plate failure. Fully encapsulating the upper pier sections proves to have a better life cycle costs than just the short term patching. Also, it is recommended that the Director of Public Works be authorized to approve up to $35,000 for the second part of the upper pier refurbishment by OKL. This will help keep the project on schedule.

Date Prepared: April 7, 2015 Prepared By; Recommended by; Bryan Ritchie Peter Dance, P. Eng. Manager of Roads and Fleet Director of Public Works Reviewed By; Date: April 7, 2015 Robert J. Lamb, CEcD, Ec.D. Chief Administrative Officer Attached: 1) Pictures taken recently of the north pier and a picture from

the 2012 Biannual Bridge Report by RJ Burnside. 2) RFQ No.1 Concrete Pier Encapsulation review from CCTA.


North Pier facing south, note the spalling of 25mm in depth


North Pier facing north, note the severe spalling and crack near the bearing plate.


Picture of both piers taken during the 2012 bridge inspection. Note the difference in condition of the piers

duck bay road upper pier repair

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