ITEM #1202239A – OVERHEAD TRUSS SIGN SUPPORT FOUNDATION
Description:
Work under this item shall consist of designing and constructing drilled shaft or spread footing foundations for an overhead truss sign support. This includes all work incidental to this construction as described in this specification.
Materials:
Concrete for spread footings, pile caps, and pedestals shall conform to the requirements for Class “A” concrete in Sections 6.01 and Article M.03.
Concrete for drilled shafts shall attain a 28-day compressive strength of 4,000 psi, have a maximum aggregate size of No. 8 stone and have an initial slump between 7 and 9 inches. The slump shall not drop below 4 inches over the duration of the pour.
Reinforcing steel shall conform to the requirements of Section 6.02 and Article M.06.01.
Anchor plate shall conform to the requirements of AASHTO M270, Grade 50 and shall be hot-dip galvanized in accordance with ASTM A123.
Threaded anchor rods shall conform to the requirements of ASTM F1554, Grade 105.
Nuts for the anchor rods shall conform to ASTM A563, Grade DH. Double leveling nuts and double hex nuts shall be used to prevent loosening.
Washers shall conform to ASTM F436, Type 1 and shall be quenched, tempered and galvanized in accordance with ASTM A153, Class C.
Hot-dip galvanizing for anchor rods and nuts shall be in accordance with ASTM A153, Class C.
Mechanically galvanizing of anchor rods and nuts shall be in accordance with ASTM B 695, Class 50.
1 inch rigid metal conduit, ground rod sleeves and related hardware and end caps shall be galvanized steel conduit and shall conform to Section M.15.09.
Bonded bushings, couplings, and square head plugs shall conform to the requirements of ASTM A105.
Bare copper wire shall conform to M.15.13.
Zinc-rich field primer for touch up shall conform to the requirements of Federal Specification TT‑P-641-Type 1 and ASTM A780. The use of aerosol spray cans will not be permitted.
Ground rods shall be 5/8-inch in diameter by 12-feet long copper clad steel. The copper cladding shall be a minimum thickness of 0.128 inches. The ground clamp shall be a square‑head bolt type approved for direct burial.
Submittal Procedure:
The following submittals are required regarding the overhead truss sign support foundation. All incidental submittals not included in the table shall be sent to the District. A description of each submittal is included below.
1) Plans and Calculations for Foundation
2) Roadway Cross Section at the proposed sign support
3) Foundation Constructability Plan
4) Working Drawing for the Foundation
5) As-Built Top of Foundation Elevations
6) Final Mylar Drawings
* See special provision for Item # 1201235A – Overhead Truss Sign Support Structure for a submittal procedure
1) Roadway Cross Section
The Contractor shall submit a survey of the roadway at the station noted on the sign location plans. If there are any changes to proposed location of the foundation, the cross-section shall be re-submitted for review and approval. This survey should include the following:
· Height and offset of noise barrier from inside face of metal beam rail
· Offsets of guide rails, concrete barriers, and light posts within 25 feet of the sign location
· Existing signs supports
· Proposed signs on overhead truss
· Sign area, dimensions, placement of sign along arm, and vertical location of sign
· Structure number and sign location numbers, stationing, route number, direction of traffic
· Lane and shoulder widths
· Offset of proposed foundation
· Roadway crown elevations and ground elevations at the center line of the proposed foundations
· Edge of pavement elevations
· Top and bottom of slope elevations
· Cross slope elevations
· Proposed top of foundation elevations
· Proposed elevation at center line of truss arm
· Height from roadway crown to bottom of sign stops (18’ -0” min)
2) Plans and Calculations for Foundation
The Contractor shall submit all plans and calculation for the foundation including the following:
· Selected type of foundation
· Conduit locations in the foundation
· Load and design parameters used in the foundation design
· All dimensions of foundation
· Anchorage details using anchor rods and plates
· Time required to construct foundation
3) Foundation Constructability Plan
The Contractor shall submit a foundation constructability plan which includes the following:
· Access to area including:
o Temporary road
o Removal of guide rails or concrete barriers
o Utility locations and drainage installations that could obstruct construction
o Clearing and grubbing, this shall be accomplished in accordance with Section 2.01.
o Removal of noise barrier as required
· Traffic protection including:
o Temporary guide rails and/or concrete barriers
o The Contractor is to submit Maintenance and Protection of Traffic Control Plans for work that cannot be accomplished using the Typical Traffic Control Plans
· Maintenance & Protection of Traffic Plans for all work that cannot be accomplished using the Typical Traffic Control Plans contained in the special provision for item 0971001A. Maintenance & Protection of Traffic Plans submitted by the Contractor shall include, but not be limited to, the following:
o All plans shall conform to the MUTCD, the Highway Design Manual and Department guidelines,
o Construction signs, traffic control devices, and temporary pavement markings,
o Direction on how to remove existing pavement markings,
o Temporary pavement markings are to be shown matching into existing markings,
o Dimensions at the beginning and end of tapers and at locations where lane and shoulder widths change,
o Any lane shifts, tapers, and shoulder closure tapers shall be designed per the MUTCD for a speed of 65 mph,
o Typical sections showing minimum lane and shoulder widths,
o Any necessary revisions to existing signs and any necessary relocation of existing signs,
o Protection of temporary gaps in guiderail,
o All plans shall be to scale.
· Drilling procedure including all calculations and specifications associated with the Contractors proposed drilling procedure and tools and machinery used when drilled shaft foundation is designed. Temporary earth retaining shall be included when spread footing foundation is designed
4) Working Drawing for the Foundation
The Contractor shall submit working drawing in accordance with Article 1.05.02 for the foundation including the following:
· Sequence plan outlining drilling, casing, installation of temporary earth retaining system, slurry, reinforcement, and concrete placement procedures for Engineer review
· All reinforcement details
· All anchorage details
o Anchor rods, nuts, washers, and anchor plates
· The Contractor shall submit working drawings to the Engineer a minimum of 30 calendar days before fabrication is to begin to allow time for review and approval.
5) As-Built Top of Foundation Elevations and Anchorage Location
The Contractor shall submit the field-verified elevations at the top of foundation elevations and the field-verified anchor rod pattern location for detailing of the steel structure.
6) Final Mylar Drawings
The Contractor is required to furnish the Engineer with a complete set of reproducible mylar drawings of all the 22 inch x 34 inch sheets after all the comments made by the Engineer are resolved. The Contractor is also required to submit electronic copies of all drawings in a DGN format
Design:
Design of overhead truss sign support foundations shall be in accordance with the 2001 AASHTO Standard Specifications for Structural Supports for Highway Sign, Luminaires, and Traffic Signals with Interim Specifications up to and including 2006. Plans and calculations shall be stamped by a Professional Engineer licensed in the State of Connecticut.
Construction Methods:
The Contractor is responsible for the selection of the foundation type, location, and proper orientation of the overhead truss sign support foundation.
Welding of reinforcing cages will not be permitted.
The Contractor shall submit a roadway cross section for approval specifying the locations and elevations for the foundations prior to submitting working drawings for the foundation and anchorage. See submittal procedure, 1) Roadway Cross Section, of this specification for details.
Drilled Shaft Foundation
A drilled shaft foundation unit consists of two drilled shafts, one pile cap and one pedestal.
This work may require rock excavation, drilling rock or using slurry filled shafts through whatever materials are encountered to reach the depths indicated on the plans and specifications. The Contractor shall submit a sequence plan outlining drilling, casing, slurry, reinforcement and concrete placement procedures for the Engineer to review.
Construction of drilled shaft shall be in accordance with AASHTO Standard Specifications for Highway Bridges 2002 Division II Section 5
The concrete shall be finished in conformance with the pertinent requirements of Subarticle 6.01.03-21.
Casings, if used in drilling operations, shall be removed from the hole. The casing may be removed as concrete is placed provided a 5 foot head of concrete is maintained, or the casing may be removed after the concrete has been poured, provided that the concrete has not been set. Separation of the concrete by hammering or otherwise vibrating the casing during withdrawal operations shall be avoided.
The maximum allowable horizontal variation of the center of the top of the drilled shaft from the required location shall be 0.5% of the shaft diameter.
The concrete shaft shall not be out of plumb by more than 1% of the total length.
Spread Footing Foundation:
A spread footing foundation unit consists of a footing and pedestal.
Spread footing foundations shall be constructed in accordance with the requirements of Article 12.02.03.
General:
The top of the concrete foundation shall be level within +1/8".
Cover for all reinforcing steel in the foundation shall be a minimum of 3”.
The anchor rod locations shall be in accordance with plans for the sign support structure.
Anchor plates in the foundation are required to have a minimum thickness of ½”.
The use of hooked anchor rods is not allowed. Only straight, galvanized anchor rods shall be used in the design.
Anchor rod assemblies shall be embedded in the concrete. The use of formed or drill holes to place the anchor rods will not be permitted.
A template to hold the required anchor rod assemblies, ground rod sleeve and conduit in their correct positions shall be used. Each of the anchor rods shall be fitted with two leveling nuts.
The leveling template shall be clamped in position by two leveling nuts at each anchor rod. These leveling nuts shall be adjusted to assure a truly level finished foundation surface at the proper elevations.
As-built anchor rod locations shall be provided to the steel sign support fabricator to insure proper fit of the support base plates on the foundation anchor rods and to confirm the span length of the truss arm.
All conduit ends terminating below grade shall be capped with a malleable iron cap. All above-grade conduit ends shall be terminated with an insulated bonding bushing with tinned insert. There shall be conduits in the foundation.
Ground rod and ground wire shall be installed as shown on the plans.
Method of Measurement:
This work will be measured for payment by the number of foundation units completely installed and accepted. Two foundation units are required to support an overhead truss sign support. Each of the two units will be measured for payment.
Basis of Payment:
The work will be paid for at the contract unit price for “Overhead Truss Sign Support Foundation,” complete in place. The price shall include field survey, layout, materials, drilling, rock socket, temporary casing, slurry, excavation, rock excavation, cutting and removing existing pavement, granular fill, backfill, concrete, reinforcing, anchor rods and plates, rigid metal conduits, ground rod, ground wire, clamps and surface treatments to be restored, as directed by the Engineer, and all equipment, labor, tools and work incidental thereto.
No additional payment will be made for the Contractor to test the slurry when it is used to construct a drilled shaft foundation.
Temporary sheeting, if required, will not be paid for separately, but will be included as part of the work.
Borrow, if required, will not be paid for separately, but will be included as part of the work.
The removal of existing roadside barrier systems, installation and removal of temporary roadside barrier systems and resetting existing roadside barrier systems will not be paid for separately, but will be included as part of the work.
The temporary support, protection and restoration of utilities (if necessary), including existing underground wiring, conduits, drainage structures, pipes and underdrain systems within the excavation limits will not be paid for separately, but will be included as part of the work.
The restoration of existing surface treatments (pavement, slope protection, topsoil & seed, etc.) in all areas disturbed by the work will not be paid for separately, but will be included as part of the work. The Engineer will determine the type, thickness and horizontal limits of the surface treatments to be restored.
The installation of new or upgraded permanent roadside barrier systems, if required, will not be paid for as part of this work, but will be paid for under separate items.
Item #1202239A