501TEMPORARY BRIDGE

New Hampshire Department of Transportation Standard Specifications – 2016

Description

1.1This work shall consist of the design, furnishing or obtaining, construction, maintenance and removal of a temporary

bridge(s) and, if specified, the approaches to the temporary bridge meeting the requirements shown on the plans or contained herein. The work shall also include the design and construction of temporary abutments an d piers, as required, bridge rail, connection to portable concrete barrier or temporary guardrail, and furnishing all equipment to install and dismantle the temporary bridge. The limits of the available work area shall be as indicated on the plans or as p ermitted. Materials

2.1All materials to be used in the construction of the temporary bridge shall be subject to inspection and approval by the Engineer

prior to their incorporation into the work. Used material will be acceptable, provided appropriate allowances are made for their condition. 2.1.1 Steel sheet piling shall conform to Section 506. 2.1.2 Steel bearing piles shall conform to Section 510. 2.1.3 Concrete shall conform to Section 520. 2.1.4 Reinforcing steel shall conform to Section 544. 2.1.5 Structural steel shall conform to Section 550. 2.1.6 Structural timber shall conform to Section 568. 2.1.7 Bridge rail shall be galvanized steel conforming to Section 563.2.

2.2The Contractor shall provide the temporary bridge incorporating one of the following sources:

Acrow Corporation of America, Maybe Bridge, Inc., or equal subject to approval by the Department, Contractor supplied, purchased or leased under separate agreement.

decking, Contractor supplied and constructed. Construction Requirements

3.1Unless otherwise specified on the Plans, the temporary bridge, including the rail system and substructures shall meet the

minimum strength requirements of an HL -93 design loading and pedestrian loading as required and specified in the AASHTO “ LRFD Bridge Design Specifications”. The bridge, including superstructure, rail system, and substructures shall be designed by a Licensed Professional Engineer. 3.1.1 Detailed plans, showing sizes, arrangement, and quality of the materials to be used in the construction and calculations of the proposed temporary bridge shall be stamped with the seal of the Licensed Professional Engineer, signed and submitted f or documentation to the Engineer in accordance with 105.02. Submitta ls shall also include an erection plan describing the method of erection proposed and the amount and character of equipment proposed. Plans shall be documented and authorization to proceed with construction shall be obtained before construction is started . The Engineer responsible for design of the superstructure shall provide a stamped and sealed NHDOT rating form (Form 4) showing the moment and shear capacities of all structural components (such as slab, decking, girders, stringers, transoms, and/or trus ses) for single lane and multiple lane loading (contact Bureau of Bridge Design (603) 271-2731 for copy of the form). The components shall be reported in HS tons using the HS-Truck portion of the HL-93 load, for multiple lane and single lane loaded conditions, load distribution, and load and resistance factors based on AASHTO Manual For Bridge Evaluation Load and Resistance Factor Rating Methods. As provided in 105.02, such documentation shall not relieve the Contractor from any responsibility under the Contract. 3.1.2 When more than one Engineer is responsible for the design of separate components of the temporary bridge (i.e. substructure and superstructure), the Contractor shall make one submittal for documentation co ntaining all portions of the temporary bridge unless otherwise allowed.

3.2The temporary bridge shall have a minimum clearspan length as shown on the plans. The minimum low steel elevation with

provisions for any anticipated sag and dead load deflections shall be maintained as noted in the Contract plans.

3.3The temporary bridge and approaches shall be designed to accommodate the free passage of vehicles, including snowplows,

for either one-way, two-way, or pedestrian traffic as specified on the Plans. The bridge shall provide for a clear width as shown on the plans.

New Hampshire Department of Transportation Standard Specifications – 2016

3.4All approach work shall be performed in accordance with the applicable specifications.

3.5No trees shall be removed without approval.

3.6For Modular Prefabricated Panel Bridge Systems, the Contractor shall submit, for approval, a detailed proposed sequence of

erecting and dismantling of the bridge components. Plans shall be prepared by a Licensed Professional Engineer with the assistance of the manufacturer of the bridge system. Plans shall be approved before construction is started. 3.6.1 The Contractor shall have a representative from the manufacturer of the bridge system present during the erection and dismantling of the bridge components.

3.7The Contractor shall maintain the temporary bridge until removal. The maintenance shall consist of weekly joint inspections

by the Department and the Contractor as to the condition of the bridge and any repairs deemed necessary by the Engineer.

3.8If the Contractor elects to use an alternate bridge system at any time during the Contract, the alternate bridge system shall be

in place and operational before removal of the existing temporary bridge system.

3.9When the temporary bridge and approaches are no longer required, they shall be complet ely removed and the area restored

to its original condition or as shown on the Plans, or as directed. Method of Measurement

4.1Temporary bridge and temporary bridge including approaches of the type specified will each be measured as a unit. No

separate measurement will be made for multiple structures required to provide the temporary bridge as required. When more than one unit is specified in the Contract, separate item numbers will appear for each separate and complete unit.

4.2Measurement of Approach Work.

4.2.1 When Item 501.1, Temporary Bridge of the type specified, is used, specific items for the approach work will appear in the Contract and measurement of these items will be in accordance with their respective sections. 4.2.2 When Item 501.2, Temporary Bridge including Approaches of the type specified, is used, all temporary bridge approach work will be included in the unit measurement. Basis of Payment

5.1The accepted Temporary Bridge and Temporary Bridge including Approaches of the type specified will each be paid for at

the Contract Unit price. Pay items and units:

501.1Temporary Bridge Unit

501.11Temporary Footbridge Unit

501.2Temporary Bridge including Approaches Unit

501.21Temporary Footbridge including Approaches Unit

New Hampshire Department of Transportation Standard Specifications – 2016

Description

This work shall consist of the removal and satisfactory disposal of the existing bridge structure as shown on the plans, except

such portions thereof as may be required or permitted to be left in place, or portions designated for salvage. Construction Requirements

The Contractor shall dismantle the existing structure in any manner that will not cause damage to persons or prope rty.

Removal of those portions of the existing bridge over roadways, railroads, and waterways shall be accomplished with the least possible disruption of the normal traffic flow under the bridge. Special care and precautions, including protective structu res as required or ordered, shall be taken to ensure that no debris including slurry from sawcutting is allowed to fall on any roadway, railroad, or waterway. 3.1.1 Detailed plans showing the size, arrangement and quality of materials to be used in the rem oval of existing bridge structures and the construction of protective structures shall be submitted for documentation in accordance with 105.02. Plans shall show the proposed method(s) of removal, all required falsewor k, protective structures and equipment needed to accomplish the structure removal safely. 3.1.2 Lead-Bearing Paint.

contain hazardous concentrations of lead.

members, etc.) involving bridge components with LBP in conformance with the applicable worker protection provisions of OSHA 1926.62, Lead Exposure in Construction Final Rule; and LBP debris shall not be permitted to enter the environment in conformance with the environmental protection requirements of the NH Department of Environmental Services.

and environmental protection measures. The Contractor shall not commence with bridge removal work until receiving Department approval of the compliance plan.

LBP unless directed otherwise.

If it is specified that the existing structure, or any portion thereof, is to be salvaged, it shall be dismantled and removed in

such a manner as to avoid damage to any member thereof. All structural steel me mbers shall be marked with paint indicating member size and grade of steel. 3.2.1 If it is specified that any part or parts of the existing structu re are to be salvaged for re- errection, all members shall be match-marked with paint before they are dismantled. All pins, bolts, nuts, loose plates, and the like shall be appropriately marked for identification and be placed in durable containers. Salvaged materials shall be stored in neat piles within the limits of the right- of-way adjacent to the work or loaded onto trucks as directed.

All parts not designated for salvage on the plans or in the special provisions shall become the property of the Contractor and

shall be satisfactorily disposed of by the Contractor. Method of Measurement

This item will be measured as a unit. When more than one unit is specified in the Contract, separate item numbers will appear

for each separate and complete unit.

Limits of work shall be as established on the plans either by detail or by note. Unless otherwise shown, the horizontal limits

will not exceed the neat lines of the portion of the structure to be removed. 4.2.1 Unless otherwise shown on the plans, when the horizontal limits of bridge excavation, roadway excavation, or channel excavation fall within the spe cified removal limits of existing abutments, wingwalls or piers, the removal of the substructure material will be paid under the governing excavation item. Only portions of the existing bridge substructure which fall outside the horizontal limits of all other excavation items will be included as part of this item. Basis of Payment

The accepted removal of existing bridge structure will be paid for at the Contract unit price.

5.1.1 Protective structures, if required or ordered, will be subsidiary. Pay item and unit: 502. Removal of Existing Bridge Structure Unit