07-10-2012
a. Description.
This work includes all labor, materials, and equipment necessary for the design, sealed shop drawing and sealed calculation preparation and submission, fabrication, manufacturing, shipping, and erection of the precast wingwalls and the precast sill foundations. The precast wingwalls and sill foundations shall be in accordance with the details as shown on the plans and the project specifications.
Reference to sections shall be in accordance with the numbered section of the “2012 Standard Specifications for Construction” issued by the Michigan Department of Transportation.
b. Materials.
The materials shall be in accordance with Sections 706, 707, and 708.
The minimum precast 28 day concrete compressive strength shall be 5,000 psi.
All embedded lifting hardware shall comply with ASTM A36-08 - Standard Specification for Carbon Structural Steel and shall be galvanized in accordance with ASTM A123-12 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products.
The non-shrink, non-metallic grout shall be used at the locations as shown on the Plans in accordance with the Plans.
c. Construction.
1. Precast Wingwall Design
A. The design of the precast wingwalls shall be in accordance with AASHTO LRFD Bridge Design Specification, latest edition.
B. The precast wingwalls shall be designed by the Contractor’s licensed professional engineer who is registered in the State of Michigan.
C. Lateral earth pressure shall a minimum equivalent active fluid pressure of 90 pounds per cubic foot.
D. The surcharge load shall be equivalent to at least 2 foot of overburden soil height.
E. The exposed surface of wingwalls shall receive a form liner with a nominal 2 inch thickness, as noted on the Plans.
F. The precast wingwalls shall resist overturning and sliding with a granular filled wingwall anchor block. Precast “L” shaped wingwalls without anchor blocks shall not be acceptable.
G. The allowable bearing pressure shall be limited to 2,500 pounds per square foot.
H. The wall thickness shall consist of a 10” structural wall with a nominal 2” form liner surface along the exposed face of wingwall.
I. Minimum Factors of Safety:
Overturning / 2Sliding / 1.5
Bearing Capacity / 3
2. Precast Sill Foundation Analysis
The precast sill foundations shall be in accordance with the design drawings. The structural dimensions and steel reinforcements shall be as shown on the drawings unless the Contractor’s licensed professional engineer, who is registered in the State of Michigan, determines that structural changes are required to accommodate the Contractor’s means and methods for manufacturing, shipping, and erection.
d. Measurement and Payment.
The completed work as measured for PRECAST WINGWALLS AND SILL FOUNDATIONS will be paid for at the contract unit prices for the following pay items:
Pay Item Pay Unit
Precast Wingwalls, Furn and Erect …………………….………..……………………..…..…Each
Precast Sill Fdn, Furn and Erect ………………………………………..….………..……..…Each
Precast Wingwalls, Furn and Erect will be measured on an individual each basis based on Plan quantities. Payment of this item shall be payment in full for all costs associated with furnishing and installing “Precast Wingwalls, Furn and Erect.”
The following items will not be measured and paid for separately and will include the furnishing of all labor, materials, and equipment as necessary to complete this work, and are included in the bid item “Precast Wingwalls, Furn and Erect”:
1. Contractor’s licensed professional engineer who is registered in the State of Michigan shall design the precast wingwall.
2. Contractor shall prepare detailed sealed wingwall calculations and shop drawings for the Engineer’s review prior to manufacturing.
3. Manufacturing, shipping, and erection of the four precast wingwalls.
4. Furnishing and placement of the non-shrink, non-metallic grout necessary for erection.
Precast Sill Fdn, Furn and Erect will be measured on an individual each basis based on Plan quantities. Payment of this item shall be payment in full for all costs associated with furnishing and installing “Precast Sill Fdn, Furn and Erect.”
The following items will not be measured and paid for separately and will include the furnishing of all labor, materials, and equipment as necessary to complete this work, and are included in the bid item “Precast Sill Fdn, Furn and Erect”:
1. Contractor’s licensed professional engineer registered in the State of Michigan shall analyze the precast sill foundations as shown on the Plans for the Contractor’s means and methods of manufacturing, shipping, and erection.
2. Contractor shall prepare detailed sealed calculations and shop drawings for the Engineer’s review prior to manufacturing regarding the above noted analysis.
3. Manufacturing, shipping, and erection of the four precast sill foundations.
4. Furnishing and placement of the non-shrink, non-metallic grout necessary for erection.
5. Furnishing and installation of #6 vertical steel reinforcement dowel bars through the box culvert into the precast sill foundation units.