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ARCHITECTURE & GENIE CIVIL

Ohio River Bridge. Typical cantilever and suspended span bridge, showing the truss geometry in the end span and cantilevered portion of the main span. (Madison, Indiana)

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Modern parallel-chord truss consisting of three square panels cantilevered from the left end. Made of flexible spines, all joints rigid. Single diagonal in each panel.

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Effect of vertical upward end load. Compression members can be seen by their tendency to buckle. Long diagonals in tension, short verticals in compression due to shear direction. Truss buckles as a system due to rigid joints and joint rotation.

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Effect of vertical downward end load. Lower buckling load as due to the direction of shear the long diagonals are now in compression and shorter verticals in tension. Lower chord also in compression. Again truss buckles as a complete system.

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Simple Pratt truss in exhibition hall. Direction of diagonals such that all are in tension due to a UD load on the truss. (Las Vegas, Nevada)

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Detail of pin-jointed truss connection, approach span to San Francisco-Oakland Bay Bridge. Pin joints are used in older bridges or situations where rotation has to be allowed for due to settlement, or for construction purposes. (San Francisco Bay Area)

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Crumlin Viaduct. Designed by Brunel (1806-59), this early railway viaduct is interesting in that it is constructed entirely from pin-connected iron members. (Ebbw Vale, Wales)

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Lift bridge, Sacramento River Delta. This simple bridge is used to introduce many aspects of truss bridge design. Details are shown in GoddenD9-D17. A Warren truss with verticals is used throughout. Lift span is simply supported. The double spans on each side are determinate due to internal pins. (Near Rio Vista, California)

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Lift bridge, Sacramento River Delta. Lift span shown partially raised. Note the counterweights that balance the lift span have dropped to the mid-height of the towers. (Near Rio Vista, California)

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Close-up of the towers. In a direction parallel with the bridge axis the bracing consists of a Warren truss, and in the other direction it is a K-truss. (Near Rio Vista, California)

STRUCTURE TREILLIS

Ohio River Bridge. Typical cantilever and suspended span bridge, showing the truss geometry in the end span and cantilevered portion of the main span. (Madison, Indiana)

STRUCTURE TREILLIS

Ohio River Bridge. Typical cantilever and suspended span bridge, showing the truss geometry in the end span and cantilevered portion of the main span. (Madison, Indiana)

STRUCTURE TREILLIS

Ohio River Bridge. Typical cantilever and suspended span bridge, showing the truss geometry in the end span and cantilevered portion of the main span. (Madison, Indiana)

STRUCTURE TREILLIS

Ohio River Bridge. Typical cantilever and suspended span bridge, showing the truss geometry in the end span and cantilevered portion of the main span. (Madison, Indiana)

STRUCTURE TREILLIS

Ohio River Bridge. Typical cantilever and suspended span bridge, showing the truss geometry in the end span and cantilevered portion of the main span. (Madison, Indiana)

STRUCTURE TREILLIS