US 2062985 A
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Description (OCR text may contain errors)
Dec. 1, 1936. 1.. u. E. A. BATICLE 4 2,062,985
SUSPENSION BRIDGE Original Filed June 30, 1931 Patented Dec. 1, 1936 UNITED STATES PATENT OFFICE SUSPENSION BRIDGE Louis Urbain Edgar Antonin Baticle, Paris, France 1 Claim.
This application is a divisional application of my co-pending application Serial No. 547,943,
filed June 30, 1931, and relates to improvements applicable to suspension bridges permitting a re- 5 duction in the deformations of the main cables.
The present invention and its aims and objects will be readily understood from the following description taken in connection with the accompanying drawing of illustrative apparatus em- 0 bodying the features of the invention, the true scope of the invention being more particularly pointed out in the appended claim.
In the drawing:
The figure is a diagrammatic view showing one embodiment of the invention.
The parent application claims an arrangement for anchoring the extreme third portions of the parabolic supporting cables of suspension bridges, such that the anchored parts constitute with the anchor elements triangulated, indeformable frameworks. The said anchor elements serve as rigid struts due to the fact that they receive an initial or pre-tension sufficient to remain always stretched under the influence of the most unfavorable overloads. In this construction a plurality of anchorage elements are used which are connected at spaced points to the main suspension cable and to piers below the bridge floor, the points of connection of said anchorage ele- 30 ments to said suspension cable being distributed over a distance of approximately one-third of the span from the respective piers, and all of said anchorage elements being pre-tensioned to such an extent that the maximum overload of the bridge does not overcome said tension, whereby sagging of the main cable and of the main floor under any load is prevented. The essential result sought, namely the fixity almost to the state of elastic deformation, of the two points of the main cable is thus attained.
The above described arrangement according to the parent case is particularly suitable for bridges, the platforms of which are heavy, because the section of. the anchor elements, which is a function of the amounts of the overloads, reaches satisfactory values and the initial tension .of its anchor elements does not reduce considerably the flexure of the central part.
The present application relates to a modified arrangement disclosed in said parent application for accomplishing the same desirable result. In this example, fixity of the points of attachment of the anchors or guys to the main cables is insured by supplementary horizontal cables stretched between the pillars at the level of. the points of attachment of the anchors to the main cables. This arrangement is advantageous, in that it is only necessary to pre-tension the anchors or guys to such an extent, in excess of the usual tension to prevent sag, as to prevent the most unfavorable overloads from overcoming the tension therein. Moreover, the arrangement is particularly suited to transporter bridges or other similar suspension structures which are subject to heavy live loads.
Referring to the diagrammatic illustration, one of the main suspension cables BB1 is shown as being connected to the vertical pillars. Anchors or guy wires bH and blHl, one for each pier, are connected to the main cable at points intermediate its ends and, preferably at the same level. These guy wires are also anchored to the piers below the bridge floor level. A horizontal cable Cl-IH1C1 is stretched between the pillars and tied to the main cable at the points HH1. Now, the anchorage elements are pre-tensioned sufficiently to overcome any permissible live load. Thus, the suspension is fixed to fixed parts of the ad jacent towers and the anchorage connections 5 prevent any substantial flexure of. the main cables. This arrangement is especially advantageous when the platform of a suspension bridge is very heavy. O
I am aware that my invention may be embodied 3 in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire that the present illustrative constructions be not considered restrictive, reference being had to the appended claim rather than to the foregoing description to indicate the scope of the invention.
In a suspension bridge of. the character described, guy wires connected to the main suspension cables and to the piers below the bridge floor constituting anchorage elements for the main cables, said guy wires being pre-tensioned to such an extent in excess of the usual tension necessary to prevent sag, as to prevent the most unfavorable permissible overloads on the bridge from overcoming the tension therein; and horizontal cables stretched between and secured to the towers of the bridge, said horizontal cables 50 being connected to the suspension cables and guy wires at the points of connection of the guy wires to the main cables.
LOUIS URBAIN EDGAR ANTONIN BATICLE.