718STRUCTURES FOR TRAFFIC CONTROL DEVICES AND HIGHWAY LIGHTING

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ensure that the anchor bolt threads are not damaged prior to installation of the support structure. Out-of-position anchor bolts and anchor bolts greater than 1:40 out-of-plumb are cause for rejection of the base. Bending of the anchor bolts to straighten or move into position will not be permitted. The number and configuration of the nuts and washers required for anchor bolts shall be in accordance with the details shown on the plans. Anchor bolts for slip bases shall have the nuts installed in accordance with the requirements given in Section 710. Anchor bolts for non-slip bases shall have their top nuts tightened by the turn of the nut method as follows:

the base plate. The bottom of a leveling nut must be kept as close to the concrete base as practical and shall not be greater than 1 inch {25 mm} away from the top of the concrete base. A leveling nut shall be adjusted on the anchor bolt so that, after the installation of all plates and nuts, there is at least a 1/4 inch {6 mm} projection of the anchor bolt above the top or lock nut (when in its final position).

of the joint are in firm contact. This may be attained by a few impacts of an impact wrench or the full effort of a man using an ordinary spud wrench.

in full bearing on the base plate. If any gap exists between the nuts, washers and the base plate, a beveled washer shall be added to eliminate the gap. The beveled washer shall be stainless steel type 304, shall be the same diameter as the other washers, and shall be beveled as required to eliminate the gap between the nuts, washers and the base plate.

turn. There shall be no rotation of the leveling nut during top nut tightening.

of forty-eight hours after the nuts have been rotated the additional one third turn. Any nuts found loose shall be tightened in accordance with the above procedure.

Attention is directed to the fact that the structure design as well as shop drawings for the fabrication of the structure must be approved before actual fabrication of a structure is started. All parts of a structural unit shall be assembled on the project and the Engineer provided with adequate field erection details before permission will be given to erect the structure. The Contractor shall temporarily brace the structure as needed.

Strain and mast arm poles shall be installed with the proper vertical offset (or rake), as recommended by the manufacturers so as to assure a substantially vertical set when the load is applied. Threaded adjusting nuts shall be used to establish the "rake" in accordance with the requirements for the installation of leveling nuts on anchor bolts. The use of shims or other leveling devices will not be permitted. Hardware and fittings shall be installed as shown on the contract plans and approved shop drawings. Messenger cable supporting traffic signal heads shall not be sagged to a vertical distance greater than five percent of the length of the span between strain poles. Messenger cable supporting signal control cable only shall be sagged to a vertical distance not greater than two percent of the length of the span between strain poles. Tether cables shall not be sagged to a vertical distance greater than five percent of the length of the span between strain poles.

Extreme care shall be taken during installation of the luminaire assembly, Intelligent Transportation Systems equipment and surveillance devices to ensure that no damage occurs to these devices. Double nuts and washers shall be used to plumb the pole about its center axis if a twin bracket is used. When a single arm type is used, the back side of the pole shall be plumbed after the luminaire and surveillance devices and hardware have been installed, thus providing a slight rake from the traveled way.

VEHICULAR IMPACT ATTENUATOR ASSEMBLY 621

718.05Submittal of Designs and Details

Working drawings, including foundation details for sign structures when required, shall be submitted in accordance with Subarticle 105.02(c) “Working Drawings”. The details shall include fabrication requirements such as the welding requirements for sign frames and tensioning and detensioning procedures for prestressed concrete poles. The design computations shall address all members, connections (welds, bolts, etc.), anchor bolts, and foundations. The designer shall note on the design computations where the design of each member meets the design requirements and deflection tolerances. Design computations shall include all formulas used and a copy of all calculations for each structure that cover all members, connections (welds, etc.), footings and details necessary for a complete structure design. Where computer generated designs are used, the information shall include the applied loadings, structure geometry, effective wind area and location of attachments (sign panels, signals and light fixtures), component sizes, moments, shears, reactions, component forces, component stresses, allowable component stresses, combined stress ratios, and deflections for each group loading specified in the AASHTO Sign Specifications. VEHICULAR IMPACT ATTENUATOR ASSEMBLY

720.01Description

This Section shall cover the work of furnishing and installing vehicular impact attenuator assemblies of the design shown in the detailed plans at the locations designated by the plans, the proposals or directed.

720.02Materials

Materials furnished for use in the manufacture of the assemblies shall comply with the requirements noted in the detailed plans. Materials used in the actual installation of the attenuation in the work shall comply with appropriate provisions of these specifications.

720.03Construction Requirements

Any installation which is to be performed under traffic shall be provided with adequate warning and protective devices until such time as the assembly becomes usable. Once work begins, it shall be prosecuted diligently and continuously until the assembly is completely installed.

720.04Method of Measurement

Vehicular impact attenuators of the design designated by the plans or proposal will be measured in assembly installations, complete in place at the designated locations.

720.05Basis of Payment

The accepted impact attenuator assemblies, measured as noted above, will be paid for at the contract price bid for each assembly. Said unit price bid shall be full compensation for the furnishing of all materials and the installation of the designated assembly on its foundation, in its designated location, and includes furnishing of all equipment, tools, labor and other incidentals necessary to complete the work and provide an operational assembly complete in place.

720-A Vehicular Impact Attenuator Assembly ( * ) - per each * Description and Model of Attenuator Assembly