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22. Mary Ave Bicycle Footbridge PUBLIC WORKS DEPARTMENT CUPERTINO Summary AGENDA ITEM J). AGENDA DATE AU2Ust 21. 2007 SUBJECT AND ISSUE Approval of the Cable Stayed Structural Steel Alternative Design Concept for the Mary Avenue Bicycle Footbridge in lieu of the Prestressed Concrete Design previously Approved by the Council. Authorize the City Manager to negotiate and execute a contract with HNTB, Inc. (NE Division) for the alternative structural steel design of the project at a cost not to exceed $ 725,000 and $50,000 in additional services, which may be approved by the Director of Public Works. Authorize the City Manager to negotiate and execute a contract with Leslie E. Robertson Associates (LERA) for the peer review and plan check and other necessary structural engineering services of the steel design alternate in an amount not to exceed $120,000 with $30,000 for additional services, which may be approved by the Director of Public Works. BACKGROUND On December 5, 2006 the Council accepted a progress report on the Mary Avenue Bicycle Footbridge Project. The project is a single span cable stayed bridge over Interstate Route 280 connecting an established bicycle trail system on Mary Avenue in Cupertino on the south side of 1-280 to Mary Avenue in Sunnyvale on the north. The design concept, developed by city staff and the design consultant team of Biggs-Cardosa Associates and HNTB, Inc had been approved by the Council on February 1,2005. The project was advertised for competitive bidding on March 2,8, 2007 and bids were received and opened on May 3, 2007 resulting in two bids, both of which were in excess of $12 Million which represented a variation of 100% over the Engineer's estimate. On Staff s recommendation, the Council acted on May 10, 2007 to reject both bids and authorize the Director of Public Works to evaluate the plans and specifications, review the estimate and report back to Council with recommendations regarding the re- advertising of the project. 1 ANALYSIS The staff has followed two separate but parallel tracks of action in analyzing the bids and reconsidering the design components of the project. The first track (A) involved the original design team (Biggs-Cardosa Associates and HNTB, Inc) and the construction manager (Swinerton CM) working with staff to both determine the accuracy and/or insuffi~iency of the original engineer's estimate of $ 6.3 Million as well as to consider changes in the documents and some additional value engineering to attempt to further reduce the cost. This work was performed by the design team at no additional cost to the City. The second track (B) involved an outside consultant team of structural and civil engineers to also consider these issues independently of the first track and, in addition, to suggest alternative designs that could substantially reduce the cost of the current concrete alternative. This team included the Northeast Division of HNTB and the structural engineering firm ofLes Robertson and Associates (LERA). Both of these two consultants are located in New York City and are working independently of the local team. FINDINGS After a great deal of analysis and review of the estimates, quantities, bidding climate and other considerations, the local design and CM team, along with the New York City team, the activities and conclusions from both Track A and Track B Teams have discovered a number of factors that contributed to what now is clearly a significantly insufficient estimate of $ 6.2 Million for construction of the bridge. These factors fall into three specific categories. These categories are (1) factors that the design team should have known or had been reasonably able to determine before the project was advertised and, as a result, incorporated into the estimate, (2) factors which may have come into being as the project was being bid in March-May time frame, and (3) factors which no-one could have predicted or even imagined would be present in such measure as to radically affect the bids received. A detailed discussion of these categories is contained in Attachment 'A' of this report. However, a summary of these categories and their probable impact on the Cost Estimate is as follows: Original Bid - Engineer's Estimate (May 2007) $ 6,200,000 Category 1 Impacts Category 2 Impacts Category 3 Impacts (Costs, timing, constructablity) (Bidding Climate/Market) (Unknowns during bidding) 4,500,000 1,500,000 500,000 Total with Probable Impacts on the Bid: $12,500,000* *The.actuallow bid was $ 12,446,732 2 Given the resources available to the original designers, it is unclear why all this information and the resulting cost factors and impacts in both Category 1 and 2 above were not addressed in the bid. The reviewers from outside firms and the contractors themselves have all pointed this out in the course of the evaluation of the project post-bid openmg. Estimates of the effect these factors, if acknowledged in the Engineer's Estimate would have added up to $ 4-5 Million to the estimate back in May 2007, which would have resulted in an Engineer's Estimate of at least $11 Million. CONCLUSION As a reminder, it should be noted first and foremost that this Cupertino project is the only cable stayed pedestrian bridge over an Interstate Highway in California. Unfortunately, that fact notwithstanding, the inescapable conclusion is that others appeared to have had a better picture of the cost of the construction of this project than our consultants had when the proj ect was bid. It would have served the City's decision making process better at the time had the City known of this potential. Staff instead relied on the special expertise and experience of our design team, particularly the structural engineers, Biggs Cardosa Associates. However, the consultants failed to accurately define the expected price in bidding the project, and, as a result, City finds itself in its current awkward position after the bidding process. All the factors discovered since the bid opening have contributed to the conclusion that the current engineer's estimate for the bridge, corrected for escalation, is more accurately expressed as $13,000,000, almost $ 7 Million greater than the original estimate and more closely aligned with the bids received over three months ago on May 3,2007. Other factors, a longer period of construction management and oversight, a larger contingency, as well as the cost of the value engineering efforts will all combine for a total cost for the entire project of at least $19.6 million. With the current revenue of $10.7 Million, to proceed with rebidding even a revised concrete design, the project would require that the City invest almost $ 9 Million in additional General Fund resources to advertise the repackaged project for competitive bids. However, for all the reasons noted above, the fact remains that if we re-bid the current concrete design, there is no guarantee that the bids we might receive will be less than those received previously. In fact, they might be even higher now that the project has been advertised in the current volatile bidding climate. In conclusion, for all these reasons staff does not recommend proceeding with the project as currently designed. 3 STEEL BRIDGE DESIGN ALTERNATIVE The New York VE (Value Engineering) team of HNTB NE Division and Leslie Robertson and Associates (LERA) in addition to evaluating the current concrete design and its erroneous estimate along with the City's construction manager, Swinerton CM, have all concluded that a much more efficient and cost effective design would be to construct the bridge out of structural steel instead of concrete. A preliminary design was authorized by staff to evaluate the cost and schedule impacts of redesigning the project with the same architectural concept (two A-frame towers with a cable stayed deck spanning the entire reach of Interstate 280) but constructed largely from structural steel. The architectural appearance and striking nature of the design would be maintained and, as such, there would be very little difference in appearance from the original concrete design. However, what we have learned in this evaluation process is that for a cable-stayed structure, steel is easier to fabricate and erect and, when all things are considered it is potentially less costly than the high strength concrete bridge as currently designed. We did not initially consider a steel bridge alternative because there was no indication from any comer of the industry at that time, especially from our consultants, that the concrete bridge would be so much more complicated to build and, as a result, more expenSIve. Steel Bridge Advantages The advantages of moving to a steel bridge alternative are largely derived from two factors. The steel bridge is not as heavy as the concrete bridge and it is much easier to construct. The result of these two factors provide a number of advantages as follows: Towers: The steel towers can be fabricated in a steel shop and transported to the site. They can be fabricated in half sections to facilitate transportation and erection in place. Because there is no need to use concrete forms and a complex array of reinforcing steel nor for the curing and heat control of high-strength concrete, the construction schedule is shorter and the tower construction is considerably simplified as are the cable connections. Also, the use of a modem paint system reduces maintenance demands. Superstructure: The steel framing eliminates the need for heavy falsework (the temporary supports under the bridge and over the freeway) and using erection towers instead provides for the fabricated girders for the deck sections to be placed with less impacts to traffic (fewer lane closures) and it can be done more expeditiously. The precast concrete deck material placed on the girders is also done more expeditiously and the quality control is improved. (Council may recall that our choice to use prefabricated columns and girders .on the portico in the Civic Center resulted in very high quality materials and finishes.) Also, the reduced mass and cross-sections have been shown to be extremely stable for wind effects and while reducing the seismic forces as well. 4 Stay Cables: Reduced superstructure weight of the steel bridge allows for more compact stay cables, which are less expensive to fabricate and erect, and behaves very well during a seismic event. Also the connections on the tower and on the deck are much easier to install and tension before removal of the temporary erection towers. Steel Bridge Cost Offsets While the construction cost will be less than concrete there will be some offsetting expenses that must be incurred for this alternative. The redesign cost for the New York team to convert the project as now designed into a steel structure would be $725,000 plus $50,000 in potential additional services, which, among other things, includes a new wind tunnel test for the steel version. The cost of the peer review and plan check by LERA is $120,00 plus $30,000 in potential additional services. It is expected that the design can be completed and a final engineer's estimate provided to the Council no later than October 2007 and, with Council approval and additional funding the project can proceed to the bidding process with a construction start in January 2008, a delay of six months. A summary of the project cost projections for the two options of re-bidding the concrete bridge and proceeding with the design and construction of the structural steel alternative is shown below. BUDGET I COST COMPARISON - MARY A VENUE BICYCLE FOOTBRIDGE Item Re-Bid Concrete Bid Steel Feasibility Study (Completed 2002) $ 210,000 $ 210,000 Phase I Construction (Completed 2005) 620,000 620,000 Design of Concrete Bridge (BCA) 2,310,000 2,310,000 AdminlPermitslFeesNE 850,000 810,000 Construction Phase Services (BCA) 530,000 0 Steel Design Alternative (HNTB-LERA) 0 775,000 Peer Review/Plan Check (LERA) 0 150,000 Construction Phase Services (HNTB) 0 425,000 Construction Management (Swinerton) 925,000 900,000 Cost Estimate - Bridge Phase II 13,003,000 10,085,000 Construction Contingency 1,300,000 1,000,000 Art 145,000 145,000 V alue En~ineering Deducts (275,000) (400,000) Total $ 19,618,000 $ 17,030,000 Revenue (10,734,000) (10,734,000) Shortfall $ 8,884,000 $ 6,296,000 5 As shown, with additional value engineering incorporated into the steel structure design, the current expectation is that the additional project cost for a steel structure on a January 2008 start date is expected be approximately $ 6.3 Million rather than $ 8.8 Million (or more) as would be expected the current concrete design. Staff is therefore recommending that the Council authorize the City manager to negotiate and execute both an agreement with HNTB (NE) in an amount not to exceed $ 725,000 with $50,000 for additional services which may be approved by the Director of Public Works for the redesign of the bridge to a steel structure, and with Leslie E. Robertson Associates (LERA) for the peer review and independent plan check in an amount not to exceed $120,000 with $30,000 for additional services which may be approved by the Director of Public Works. SCHEDULE Should the Council approve the staff recommendation to proceed with the design of the steel bridge alternative, the approximate schedule would be as follows: Event Date Design and Bid Approval of Steel Design Contracts Approval of Estimate, Bid and Budget and Advertise Project (8 weeks) Open Bids and Award Contract *(Council consideration at Council Meeting) August 21, 2007* September-October 2007* November 2007* Construction Structure Completion - Bridge Dedication Proj ect Completion December 2008 March 2009 The Council should note that this is an extremely aggressive and optimistic schedule at every point, which relies on the ability of staff and consultants to meet certain milestones along the way, including redoing the wind tunnel test at a laboratory in Canada and a fairly aggressive review timeline for Caltrans for the steel bridge. All players have pledged to make every effort to meet these goals. However there still could be, as yet unknown, pitfalls that might arise which could affect this schedule. FISCAL IMPACT There is no immediate fiscal impact from this action as sufficient funds are available in the project budget for this redesign work. The funds available in Account No. 428-9449- 9300 are a combination 80% grant and 20% General Fund consistent with the revenue allocation in the current adopted budget. 6 However, should the Council authorize staff to proceed when the final design report is presented to Council later this year, at that point as the project goes out to bid, an additional appropriation of approximately $6 Million would be necessary. Should that be the case staff would recommend appropriate funding sources for this effort at that time. STAFF RECOMMENDATION Approval of the Cable Stayed Structural Steel Alternative Design Concept for the Mary Avenue Bicycle Footbridge in lieu of the Prestressed Concrete Design previously Approved by the Council. Authorize the City Manager to negotiate and execute a contract with HNTB, Inc. (NE Division) for the alternative structural steel design ofthe project at a cost not to exceed $ 725,000 and $50,000 in additional services which may be approved by the Director of Public Works. Authorize the City Manager to negotiate and execute a contract with Authorize the City Manager to negotiate and execute a contract with Leslie E. Robertson Associates (LERA) for the peer review and plan check and other necessary structural engineering services of the steel design alternate in an amount not to exceed $120,000 with $30,000 for additional services which may be approved by the Director of Public Works. Submitted by: Approved for submission: :a~A~ffi7!!:Ud Lf:f Director of Public Works ~ David W. Knapp City Manager 7 ATTACHMENT A CONCLUSIONS REGARDING THE ENGINEER'S ESTIMATE Category 1 - Factors that should have been known: Apparently the Design Consultants relied mostly on Caltrans published reports of bid unit prices from current and past projects. None of this information reflected the complexity of the design, the difficulty of the construction, nor the condensed time frame. An example of the impact of the condensed time for construction is that the limited time (10 months) would have required the contractors to build both towers at the same time, thereby doubling the cost of forms, labor and scaffolding along with additional traffic control on the freeway. Further, it is apparent that the specialty pricing from suppliers and vendors (particularly concrete, steel and cables) did not the reflect actual prices being experienced on the job when a contractor adds profit and overhead to account for a difficult fabrication process during construction. Given the resources available to the original designers, it is unclear why all this information and the resulting cost factors were not addressed in the bid. The reviewers from outside firms and the contractors themselves have all pointed this out in the course of the evaluation of the project post-bid opening. Estimates of the effect these factors, if acknowledged in the Engineer's Estimate would have added up to $ 4-5 Million to the estimate back in May 2007. The analysis and evaluation of those bids clearly indicate that these factors alone could have resulted in an Engineer's Estimate of up to $11 Million. Even though the bids were over that at approximately $12.5 - $13 Million, it would have served the City's decision making process better at the time had the City known of this potential. Staff instead relied on the special expertise and experience of our design team, particularly the structural engineers, Biggs Cardosa Associates, and the City has invested over $2 million in this effort. As noted above, the consultants failed to accurately define the expected price in bidding the project which has put the City in the current awkward position after the bidding process. In short, the City should have been advised of this situation well ahead of advertising for competitive bids. The unfortunate consequence of that situation is that the project, in its current form, is "tainted" by the combination of two bids in excess of $ 12 Million that are now on the record along with the revelation by the City's consultants that the estimate was seriously in error. Category 2 - Factors that may have affected the bid pricing during the bidding period: It is clear from the outside reviews and our interviews with the contractors that the construction bidding market is, without exception, more volatile than it has ever been since the construction of the Interstate system in the 60's and 70's which had the unforeseen effect of placing the contractors in an extraordinary buyer's market. This situation was compounded by the fact that there was and is an unusually high volume of projects (many in the $50 - 100 million category) such that contractors can pick and choose with the effect of loading more profit and risk avoidance onto smaller and more complicated projects like the Mary Avenue Bridge. That volatility was apparently rapidly increasing as the Bridge project went out to bid. Category 3: Unpredictable factors unknown at the time the project was bid. Several contractors dropped out of the competition right before the bid deadline to compete for the Oakland 1-580 ramp repair, which had the potential for a very big profit in a very short period of time. If contractors are aware that there are very few bidders on any given project (only two bidders were left on this project), they will be more conservative (i.e., pricier) with their bids. This was completely unforeseen when the project was advertised. It is impossible to speculate on this potential but it may have had very little effect or up to 10 percent ($1,000,000) or more. Summary of Probable Impacts on Engineer's Estimate Original Bid - Engineer's Estimate (May 2007) $ 6,200,000 Category 1 Impacts Category 2 Impacts Category 3 Impacts (Costs, timing, constructablity) (Bidding ClimatelMarket) (Unknowns during bidding) 4,500,000 1,500,000 500.000 Total with Probable Impacts on the Bid: $12,500,000* *The actual low bid was $ 12,446,732 .~..- , ~-:'... ..._- - ...:; . .'.~. - '-" " .II' ~ "'. ~, ~\ I ~ 11 \' Ii' 110.'I \1 ~1 ~, ~ \~ l' ~ ., .. \~ \~. '~ ~l \ .'~ " '\ 'V -...- . ,