2014
Estimate Types
Programming– The project is in the concept phase. No schematic and little details
are known.
Schematic– Known• Geometrics (alignments V & H, super-elevations, typical sections), field
survey, environmental constraints, traffic loading, bridge span length, retaining wall, etc.
– Unknowns• Final pavement design, phases of construction, detours, utility conflicts,
final quantities
Final Plans– All quantities are known, the unknown unknown is the only unknown – Required to be within 3% of the lowest bid (or write a justification)
Contractors Estimate– Estimate based on the individual (contractor’s unique position)
4
2014
Bryan District Average Cost
Grade Separation
2 Lane to 4 Lane
2 Lane to Super 2 (passing zones)
Signal
Ramps
Freeway – Controlled Access
5
$ 10 Million
$ 2.3 Million/ Mile
$ 1 Million/ Mile
$ 150,000
$ 450,000/ EA
$ 12 Million/ Mile
2014
Programming
Basic estimate (Programming to preliminary Schematic)– Structures (bridges, culverts, storm drains)– Pavement • $/ mi (spread sheet)
– Signals ~ $ 150k/ EA– Miscellaneous (erosion control, striping, signs, traffic control,
etc.) • 10 – 20 % of known (subtotal 1)
– Engineering Contingencies• 6 – 11 % subtotal 2
– Mobilization• 10 % subtotal 3
6
2014
Structures
Structures (400)– Culverts (Item 462)– Reinforced Concrete Pipe (Item 464)– Inlets/ Manholes (Item 465)– Headwalls/ Wingwall (Item 466)– Safety End Treatment (Item 467)– Retaining Walls (Item 423)
Average bid for items– Go to www.txdot.gov search “low bid” – Or http://
www.txdot.gov/inside-txdot/division/general-services/bidding/average-low-bid-unit-prices.html
7
2014
Structures
Superstructure (beam type)– http://
www.txdot.gov/inside-txdot/division/bridge/specifications/super-design.html
Unit cost found here– http://www.txdot.gov/inside-txdot/division/bridge/unit-cost.html
General programming estimate (for most structures, if specialized design use the links above for more information)– Bridge • Cost = $ 75/ sf deck – includes all structure cost substructure and superstructure
– Culvert• Cost = low bid cost x length x 1.4– 1.4 factor adjust for head wall, wing wall, special trenching, junctions etc.
– Embankment = $ 10/ cy – Excavation = $ 3/ cy– Wall = $ 50/ sf
8
2014
All items
100 – Earth Work and Landscape
200 – Subgrade Treatments and Base
300 – Surface Courses and Pavement
400 - Structures
500 - Miscellaneous Construction
600 – Lighting, Signing, Markings, and Signals
700 – Maintenance
Spec Book http://ftp.dot.state.tx.us/pub/txdot-info/des/specs/specbook.pdf
9
2014
Further considerations
Considerations when Estimating Bridge Projects1. Is stage construction necessary?2. Is the replacement bridge on new alignment or the same?3. Will the replacement bridge have longer spans with deeper
beams? If so, will the grade have to be raised for clearance (hydraulics or V.C.)?
4. Will the contractor need special equipment for the project?5. Is a shoofly structure required for a railroad underpass?6. Will a pump station be required?7. Is there a shortage of materials (steel)?8. Is a relief structure also necessary?
11
Top Related