Preliminary Construction Cost Estimate - The Braided Strands
A while ago, we kindly asked one of southern ontario's largest general contractors to take a look at our design and use their experience in similar projects to estimate the construction cost of "The Braided Strands".
Today, we received their cost estimate and their summary follows:
THE BRAIDED STRANDS – PEDESTRIAN BRIDGE, TORONTO
PRELIMINARY CONSTRUCTION BUDGET
At the preparation of preliminary budget for construction costs of the pedestrian bridge, very limited information has been available (architectural layout, schematic profile and a few architectural rendering presenting the designers’ ideas from various perspectives).
In the lack of structural design, detailed geometry, dimensions of elements and data of materials and products intended to use, we had to make numerous assumptions for producing a rough cost estimate.
Most important are the structural approach and assumptions outlined below.
Structural assumptions:
The concrete-surfaced passage, the wood deck passage and the asphalt-surfaced passage represent three bridge decks. The passages shall bridge the 102.2m distance between the Front Street and City Place landings, approximately 12 meters above the Union Station Railway Corridor,
A central pier - located between the tracks of the railway corridor - divides the distance to two smaller spans (approx. 58m and 43m) and the indicated pier and cable stayed bridge system can provide support to the middle section of the bridge (approx. 46m) only.
On the north side, 33m long and on the south 23m long deck pieces branch off the main concrete deck forming irregular fork shapes. These “free†spans - not suspended by cables – shall be the most critical items at the detailed design. The structural design shall determine the material, shape and depth of the various bridge deck structures. Each shall be capable to take the dead and live loads within the deflection criteria.
The most frequently used structural systems for pedestrian bridge decks:
- Concrete deck on girders (tee, double tee or box shapes), reinforced (and post- or pre-stressed for longer spans); it can be cast-in-place or precast concrete
- Steel deck and steel girders and trusses
- Composite concrete (deck) and steel structure
- FRP structure (high strength – light weight)
- Composite FRP structure
In the budget, we assumed concrete and steel structure combinations, without having any preliminary structural design available.
THE BRAIDED STRANDS – PEDESTRIAN BRIDGE, TORONTO
PRELIMINARY CONSTRUCTION BUDGET
FOR TOTAL CONSTRUCTION COST AND COST BREAKDOWN
STRUCTURAL & CIVIL WORKS CAN $
CENTRAL PIER & CABLE STAYED SYSTEM 698,500.-
FRONT STREET & CITY PLACE LANDINGS 574,500.-
SITE WORKS 86,000.-
BRIDGE DECKS 1,267,000.-
ARCHITECTURAL & MISCELLANEOUS WORKS
ARCHITECTURAL WORKS 882,000.-
CASH ALLOWANCES 325,000.-
ELECTRICAL WORKS (lighting, lightning protection etc) 200,000
WATER & DRAINAGE (related utilities & connections) 80,000
LANDSCAPING 25,000
STREETSCAPE (benches, trashcans, bike racks etc) 20,000
COST FACTOR - WORKING IN RAILWAY CORRIDOR 10% 383,000.-
_____________
DIRECT COSTS 4,216.000.-
MOBILIZATION, SUPERVISION, GENERAL COSTS 15% 632,000.-
BOND & INSURANCE COSTS 2% 97,000.-
CONTRACTOR’S OVERHEAD & PROFIT 10% 500,000.-
____________
TOTAL CONSTRUCTION COST 5,445,000.-
The accuracy of the preliminary budget has been limited by the information available. It covers the construction costs only, does not include GST, design costs, inspection and verification costs, building permit costs, development fees, levies, utility connections and fees, or any other kind of soft costs.
SpadinaBus
Team O.R.E. (Office for Responsive Environments)