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CITY OF VANCOUVER ADMINISTRATIVE REPORT |
Date: |
February 19, 2004 | |
Author: |
Merv Robertson | |
Phone No.: |
7321 | |
RTS No.: |
03969 | |
CC File No.: |
5752-1/1805 | |
Meeting Date: |
March 9, 2004 |
TO: |
Vancouver City Council |
FROM: |
General Manager of Engineering Services |
SUBJECT: |
Consultant Appointment for a Rehabilitation Study of the Granville Bridge Expansion Bearings |
RECOMMENDATION
A. THAT, subject to the conditions set out in Recommendations C, D and E, Council authorize the General Manager of Engineering Services to engage the firm of Buckland & Taylor Ltd. for the detailed assessment study and report on the rehabilitation of the steel expansion bearings of the Granville Bridge at the estimated cost of $70,000 including GST and overhead, subject to a contract satisfactory to the Director of Legal Services.
B. THAT existing funding for this work of $160,000 be transferred from the pre-2000 Streets Basic Capital Budget for Major Maintenance - Structures in order group C07A1C0003, account number 10000439 to the 2004 Streets Basic Capital Budget, order group CB2EA1C002, with $70,000 to be used for the consultant's study and the remainder to be used for phase 1 bearing rehabilitation work.
C. THAT the Director of Legal Services be authorized to execute and deliver on behalf of the City all legal documents required to implement Recommendation A.
D. THAT all such legal documents be on terms and conditions satisfactory to the General Manager of Engineering Services and the Director of Legal Services.
E. THAT no legal rights or obligations will be created by Council's adoption of Recommendation A, C and D above unless and until such legal documents are executed and delivered by the Director of Legal Services.
CITY MANAGER'S COMMENTS
The City Manager RECOMMENDS approval of A, B, C, D and E.
COUNCIL POLICY
The appointment of consultants whose fee will exceed $30,000 must be authorized by City Council. Also, Capital funding transfers in excess of $50,000 require Council approval.
PURPOSE
The purpose of this report is to obtain Council approval to engage the firm of Buckland & Taylor Ltd. to extend the work already done on an assessment report for the rehabilitation of the steel expansion bearings of the Granville Bridge, and to approve the transfer of existing funds from the Pre-2000 Streets Basic Capital Budget.
BACKGROUND
The steel truss portion of the Granville Bridge is supported on eight concrete piers. On six of the piers, the trusses are connected to the pier tops with expansion bearings that contain rollers to allow the bridge to lengthen and shorten with changes in temperature. The rollers are enclosed in steel plated boxes filled with an oil bath which contains Aroclor 1248, a synthetic oil product containing Poly-Chlorinated Biphenyls (PCBs). There are a total of 14 bearing boxes containing about 4300 litres of the oil lubricant. This lubricant was installed in 1963 as it has the unique property of being heavier than water and this prevents rain and salt water from corroding the expansion bearing rollers. In the 1970's, PCBs became a substance considered to be a health and environmental hazard, and its use is now severely restricted by Federal Government Environmental Legislation.
In 1994 the City made application to and received approval from Environment Canada for an exemption under the regulations to allow for the continued use of the PCB lubricant. This request was based on the high cost and difficulty of removing the PCBs. The exemption was subject to the City establishing a PCB management and contingency plan, which has been in effect since that time, and following up with a plan for permanent removal of the PCBs.
There have been two bearings which have leaked in the past and while both leaks were minor and were successfully cleaned up, there is the potential that others could develop leaks in the future. The potential for a leak increases with time and for this reason funding was put forward in the Capital Plan for an assessment of the rehabilitation of the bearings and a phase-out strategy for the PCBs.
The firm of Buckland & Taylor Ltd. have submitted a proposal to prepare this assessment and strategy. The original seismic evaluation study on the Granville Bridge was performed in 1989 by Buckland & Taylor Ltd. Due to the firm's technical qualifications and history with the bridge, they were also engaged for Phase 1 of the seismic upgrading including detailed design and inspection during construction. For the Phase 2 design work, proposals were requested from three consultants including Buckland & Taylor Ltd. However, it was only Buckland & Taylor who submitted a proposal. The other two consultants declined for reasons of non-availability of suitable technical staff. However, concerns about defining the legal liabilities may also have been a factor. This becomes difficult where one consultant has done the preliminary analysis and design for a project and then another consultant is engaged to perform the detailed design and prepare construction drawings based on the first consultant's preliminary work. It was ultimately decided to engage Buckland & Taylor to perform the Phase 2 work. In light of the above, a proposal for the Phase 3 seismic work was requested only from Buckland & Taylor Ltd.
In 2001, Buckland & Taylor Ltd. was engaged to provide a preliminary assessment report investigating the condition and the alternatives for rehabilitating the expansion bearings of the Granville Bridge.
DISCUSSION
On reviewing this initial preliminary assessment report, it was determined that a number of issues needed to be further explored. As the bridge was originally designed and constructed in 1950s, modern structural analysis techniques now allow the consideration of more complex structural systems. Preliminary review of the structure indicates that it is probable that the four largest expansion bearings on the Granville Bridge could become fixed which would be substantially less than replacing the bearings, possibly reducing the cost to the $100,000 range as opposed to $1 million or more. If this is the case, the preliminary rehabilitation costs for replacing the 10 smaller bearings and converting the four largest bearings to fixed will still be over $2.5 million, but much less than originally thought.
Therefore, this current study is to include a detailed evaluation of each of the members of the steel superstructure using a computer model to confirm that the four bearings can become fixed. The consultant's work will also include preparing cost estimates for the disposal of the hazardous and contaminated materials removed during the proposed bearing rehabilitation, and a detailed analysis of alternatives for staging the bearing rehabilitation to allow work to proceed as funding becomes available.
For this current study, a proposal has again been requested only from Buckland & Taylor Ltd. They have direct experience on the bearing redesign and removal of the PCBs from the bearings on the Burrard Bridge. As the work is directly interrelated with their previous work on the bridge seismic upgrading and as they already have a computer generated structural model of the Granville Bridge which was created for the seismic upgrading, it is felt that this will allow them to perform the work more efficiently and cost effectively. Therefore it is recommended that they be awarded this project. The output of this study will be a comprehensive strategy for replacement of the bearings and removal of the PCBs.
FINANCIAL IMPLICATIONS
Based on the man-hours and fees proposed by Buckland & Taylor Ltd., the engineering services for the work including a detailed report will require funding of $70,000, including GST, City overhead and a small contingency. There is existing funding of $160,000 set aside for this work in the Pre-2000 Streets Basic Capital Budget in order group C07A1C0003, account number 10000439. It is requested that the $160,000 be transferred to the 2004 Streets Basic Capital budget, order group CB2EA1C002, with $70,000 to be used for the consultant work and the remainder to be used for phase 1 of the rehabilitation work based on the consultant's recommendations.
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