MOVABLE BRIDGE MANUAL

There are many common components between movable bridges and gate drive systems and the arrangement of drive systems between movable bridges and hydraulic gates share many similarities. These references provide extensive design considerations and criteria for a variety of drive systems including both hydraulic drives and electromechanical drives. Specific design guidance for gate drive components includes USACE and the Rijkswaterstaat document, Design of Locks. Specific engineering design analysis and calculations for mechanical drive components are provided in technical references such as Machinery's Handbook and Shigley and Mischke. The discussion of the various drive components further is intended to be general in nature and to provide the reader a broad-based overview without detailed design calculations.

These various components are discussed in the following sections.

Some of these are specific to electromechanical drives and others specific to hydraulic drives and others common to both drive types like electric motors. Ryszard Daniel, Tim Paulus, in Lock Gates and Other Closures in Hydraulic Projects, 2019 11.3.1 Design Criteriaĭrive transmission systems include a number of components.

MOVABLE BRIDGE MANUAL

The guidelines stated in FHWA Seismic Design and Retrofit Manual for Highway Bridges in conjunction with the Highway Agency Design Manual need to be followed as a minimum. If the bridge structure falls into Seismic Zone 2, an acceleration coefficient ( A) of 0.15 is applicable. However, counterweights on bascule bridges represent large seismic inertias, whose effects on the girders needs to be explored, as do seismic acceleration forces on the span drive braking machinery when the span is raised. According to AASHTO specifications, the seismic load used for the open position may be reduced by 50% if the bridge is in that position for less than 10% of the time. Hence, it is important to evaluate their seismic vulnerability in both open and closed positions and in positions in between. (London), in Earthquake-Resistant Structures, 2013 9.8.4 Retrofit of Existing Movable BridgesĪt the time when most movable bridges were constructed, there were generally no seismic codes in effect.

Movable bridge