• Plank placed over two supports
• Bends with force
• Top surface of plank growsslightly shorter because it is being compressed.
• Bottom is stretched out because it is tense.
• No more than 250 feet.

• Can span up to 800 feet.
• Identified by arch.
• The higher an arch the stronger it is
• The flatter an arch the weaker it is.
• Force is trasformed ito compressing force that is sent down through both sides of the arch into the ground.

Truss Bridge-Consists of an assemly of triangles. Commonly made from straight steel bars that add strength and suport to a structure.

Truss- Skeleton-like structure composed of struts(short straight pieces), some in compression and some in tension, joined to form a series of triangles.

Cantilevers-Similar to Truss, but are are horizontal beams each attached only at one end, and their weight is counter-balanced by the structure to which they are attached.

Cantilever Bridge-Characterized by being fixed at one end.

• Characterized by cable or series of cables that carry the downward forces to the supports and then down to the ground.
• Can span 2,000-7,000 ft. (farthest of bridges)
• Usually have truss system beneath roadway to prevent bending.
• Suspended roadway cables transfer load into compression in the two towers on the end of the bridge.
• Made of steel

• distinguishing "A" shape
• center pillars that have cables running off onto roadway
• medium length span: 500-3,000 ft.

Lamination-Process of bonding layers of materials together. Ex. Plywood

Corrugation-Process of bonding two flat layers of material with a pleated layer between. Ex. Cardboard

Tubular Girder-The strength of a tubular girder decreases as the diameter increases.

Corrugation>Lamination