scope:

GENERAL CRITERIA

These Specifications cover the design of movable highway bridges.

The requirements for fixed span bridges, as given in the latest edition of the AASHTO LRFD Bridge Design Specifications, shall apply to movable bridges, except as otherwise provided herein. The concepts of structural safety through redundancy and ductility and of protection against scour and collision are emphasized in those specifications.

These Specifications are not intended to supplant proper training or the exercise of judgment by the Designer, and state only the minimum requirements necessary to provide for public safety. The Owner or the Designer may require the sophistication of design or the quality of materials and construction to be higher than the minimum requirements.

The design provisions of these Specifications employ the Load and Resistance Factor Design (LRFD) methodology to the extent practical at the time of writing. The factors have been developed from the theory of reliability based on current statistical knowledge of loads and structural performance.

The parts of the Specification dealing with workmanship and erection are intended to be guidelines for the designer, to include as required in the specifications written for the specific project.

The structural, mechanical, hydraulic, and electrical design will be furnished by the Owner, unless it is expressly stated in the invitation for bids that such designs, or specified portions of them, are to be furnished by the Contractor.

The operating time shall be stated in the contract documents and all gates, warning devices, and operating equipment and control systems shall be designed to meet or exceed the criterion for time of opening.

The contracts shall state:

• the time of opening,

• assumed time of vessel passage, and the time of operation for both

• the main and auxiliary power.

The contract documents shall make clear the division of responsibility between the Owner and the Contractor for designing, furnishing, and erecting or installing all components of the structure, and shall fully specify or describe all of such components which are the responsibility of, or affect the work of, the Contractor.

The Contractor shall furnish and erect the structure ready for operation and to receive traffic, except for such components as are specified to be furnished or installed by the Owner.