US 4,932,178 A · Compound timber-metal stressed decks

Abstract

This invention relates to a bridge deck comprised of longitudinally positioned timbers having metal plates inserted between the timbers. Transversely positioned rods apply compressive forces to the timbers and metal plates. Resulting friction causes bridge deck components to behave as a single unit. The metal plates are inserted between timbers of various sizes and lengths of the stressed deck bridge. Proper transverse stressing of component parts by use of high strength steel rods or tendons allows shear and flexural stresses, caused by applied loads, to be transferred between plates and timbers by friction alone without glue or metal fasteners. Deflections, caused by applied loads, are greatly reduced when properly designed plates are employed. Without plates, the use of stressed timber deck bridges, under today's highway loads, is limited to short spans with large timber dimensions. Such structures are handicapped economically when compared with other types of bridge systems such as prestressed concrete or composite concrete-steel bridges. Properly designed and inserted plates have been shown to greatly improve the structural performance of stressed timber decks.

Claims20

Dependent claims

A composition bridge deck longitudinally positioned in the direction of traffic flow and having lateral surfaces thereon, comprising in combination:

a plurality of longitudinally positioned timbers comprising a plurality of timbers longitudinally butted against each other to form butt joints, said butt joints being positioned to lie adjacent to segments of continuous timbers;
a plurality of plates longitudinally positioned between said timbers in any ratio of plates to timbers;
a plurality of tensioning members transversely extending through said plurality of timbers and through said plurality of plates;
tensioning means positioned on the end portion of each of said tensioning members, and in pressure contact with the lateral surfaces of said bridge deck, said tensioning means comprised of, in combination:
bearing plates positioned on opposite lateral surfaces of said bridge deck;
anchor plates in pressure contact with said bearing plates, said tensioning members extending through said bearing plates and said anchor plates;
anchor nuts on the end portion of said tensioning members and in screw relationship thereto, said anchor nuts in pressure contact with said anchor plates;
said tensioning means and tensioning members adapted to maintain transverse pressure on said plurality of timbers and said plurality of plates.

5 more elements

Dependencies are inferred from the claim text.

Compound timber-metal stressed decks

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Compound timber-metal stressed decks

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Abstract

Claims20