US757553A - Arch-bridge construction. - Google Patents

Description

PATENTED APR. 1 9, 1904. S. W. HILL.

' ARCH BRIDGE CONSTRUCTION.

Brummen FILED-19:53.30, 1903.

N0 MODEL.

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@ZW/e6@ ees? No. #massa UNITED STATES PATENT Patented April 19, 1904.

Fries.

ARCH-BRIDGE CONSTRUCTION.

SPECIFICATION forming part of Letters Patent N0. 757,553, dated April 19, 1904-.

Application tiled March 30, 1903.

To @ZZ whom it muy concern:

Be it known that l, SAMUEL W. HILL, a citi- Zen of the United States, residing at Pittsburg, in the county of Allegheny and State of PennA sylvania, have invented or discovered a certain new and useful Improvement in Arch- Bridge Construction, of which improvement the following is a specification.

My invention relates to improvements in bridge construction, and more particularly to that class of bridges in whicha metallic framev -of either out stone, iron or steel, brick masonry, or concrete separately.

Another important object of this invention is to obviate the necessityT for use of heavy-timber frame false `work and lagging for center-.

ing and support in erection of arch-bridges.

Heretofore, so far as I am aware, it has been necessary in the erection of all forms of arched bridges to use heavy-timber framework and lagging for centering, which was removed upon the completion of the bridge.

Another object of my invention is to produce a system of concrete spandrel filling adapted to lighten the permanent load on the haunches of the bridge and also to compensate for the material omitted in the spandrels.

In the erection of my improved bridge the framework is formed at the shop in sections of built-up metallic girders in one, two, or three pieces convenient for handling, which when delivered at the place of erection are placed upon suitable foundations and riveted or otherwise secured together by light-iron tie-plates, the girders and angles of the tie-'plates being so disposed and arranged as to be entirely embedded in the concrete when applied, thus Serial No. 150,089. @lo model.)

thoroughly protecting the metallic Jframework from deterioration by oxidation, from expansion and contraction by changes of temperature, and from vibration of moving loads and making all the parts mutually supporting, diffusing all the stresses or strains equally to the foundation, avoiding concentration of stresses and strains at any particular point, so that the wider the bridge or more tracks thereon the greater the strength. The said frame is stffened by rigid continuous metallic arched girders extending longitudinally, which are connected and braced laterally` by a plurality of tie-plates extending transversely thereto, said tie-,plates being connected together at their edges and also connected at their ends to the girders, forming a complete arched frame or sheathing to support the concrete l thereabove at all points.

To avoid using false framework, the several parts are prepared as hereinafter described and erected as follows-viz., first, in preparing the foundations as described; secondly, anchoring thereto in successive order the larch girders or ribs as component parts of the metallic frame of the structure; thirdly, uniting said arched ribs laterally into a complete arched frame by tie-plates or channels, and, finally, adding a concrete body portion.

The improvement claimed'is hereinafter more fully described, reference being had to the accompanying drawings, forming part hereof, in which Y Figure l isv a side elevation, partly in verf tical section, of my improved arched-bridge construction; Fig. 2, a transverse sectional view taken on line 2 2 of Fig. l; Fig.l 3, a fragmentary top plan view of one of the'girders; Fig. 4f, a sectional end'view of one ofthe girders; Fig. 5, a fragmentary View of the tie and arch plates; Fig. 6, a plan view of the base-plate, to which the end supports are secured; Fig. 7 a fragmentary View of the anchor connection for arch-girders, and Fig. 8 a fragmentary view`of a viaduct construction embodying my invention.

Referring to said drawings, 1l indicate any suitable foundations upon which are secured or anchored the base-plates 2 2, on which are anchored the ymetallic frame A. The said frame A comprises aseries of arched built-up girders or ribs composed of parallel plates 3 3, arranged a slight distance apart, to the lower ends of which, on both sides thereof, are secured angles 4 4, the fianges thereof on both sides of said plates extending in opposite directions. Ang'les 5 5 are also secured to the upper outer ends of said plates 3, the fianges of which extend in opposite directions. The said angles 4 4 serve to reinforce or strengthen said plates 3 3 and also provide additional surfaces to which the arched plates 6 6 are secured, the said plates 6 being riveted or otherwise suitably secured to the horizontal flanges of said angles, constituting, with the brace-bars 7 7, which extend over the upper ends of plates 3 and angles 5 5, to which they are secured, the built-up girders or ribs. The said brace-bars 7 7 are,disposed at intervals on an angle over the upper face of the girder, leaving the built-up girders open to receive the concrete backing 8 and permit said concrete to completely and entirely encompass or inclose the girder, protecting the same in this manner from atmospheric changes and also equalizing the stress upon the girders. The said arched plates 6, which are securely riveted to the lower or under faces of the flanges of the angles 4 4, extend a slight distance beyond the sides of the girders for the purpose of enabling the girder tie-plates 9 9 to be secured thereto. These tie-plates, which are riveted together at their flanges, serve to unite the series of built-up girders, component parts of the structure, into a complete metallic frame and also form a base or support for the reception and maintenance of the concrete body of the structure, which completely incases all the metallic parts of the frame eX- ccpting the outer or intrados face of the arch formed by these tie-plates. The said channelbars by means of their fianges are mutually self-supporting and form excellent voussoirs to the extent of their flanges and enable the use of light or thin iron in the construction of the frame. 10 is earth filling upon the concrete, and 11 is the ballast arranged thereon.

In the erection of the metallic frame I preferably use channel-iron to form the tie-pieces to permit or enable the use of thin or light iron without buckling and also to permit the joining of the edges and render said tie pieces 'or plates mutually self-supporting in all directions of the frame, and thus produce an arched iron frame complete in all its parts ready to receive the concrete backing forming the ring and sustain stresses in all directions.

In order to lighten the steady load on the haunches of the bridge and enable the construction of arch bridges with very much longer span than has heretofore been practicable, I carry up to the horizontal plane abo've each girder from the top of the arch and under each rail of railroad-bridges a solid column of concrete backing of limited width. In the spaces between said concrete backing I insert hollow cylindrical bodies 12 12, placed horizontally to the girders and surrounded with concrete filling of a thickness suitable to the size of the cylindrical forms or bodies, the concrete filling surrounding said bodies constituting efiicient lateral supports for the concrete backing and carrying the spandrel up to the level of the crown of the arch. This construction eliminates a great part of the weight on the haunches of the bridge, unavoidable if the spandrels were filled solidly.

VTo compensate for the material omitted from the spandrels by reason of the introduction of said hollow bodies, I embed in the upper layer of concreteisteel rods 13 13 of suitable size and shape (shown in the drawings as T-shaped) and extend the same horizontally from the abutments toward the crown of the arch over said hollow spaces.

It will be particularly observed that the entire strain upon the girders is edgewise, extending longitudinally-that is, in a vertical planewthereby greatly increasing their tensile strength when embedded in the concrete. It will also be noted that the built-up girders may be formed of one, two, or more channelbars, suitably secured together, or they may be formed by combining the channel-bars and angle-irons, or, in fact, any suitable form of bars, orv by employing Z-bars and I-beams, which may be suitably riveted together, and that various other changes may be made in the details of construction without departing from the general spirit of my invention.

When two or more arches are built continuously, as in a viaduct construction, the girders of the arches at their proximate ends are connected or tied by the tie-rods 14 through the concrete abutments or piers, as shown in Fig. 8, the purpose of this being that the bending movement, tension, or thrust upon either arch is distributed to and partially sustained by the other arch and interyening pier.

I claim as my invention and desire to secure by Letters Patent- 1. A composite arched bridge, comprising a metallic frame, inherently rigid and continuous, the parts of which are self-centering and self-supporting, sustaining and embedded in an arch of concrete material, from abutment to abutment; the whole forming a solid complete arch-bridge.

2. In a bridge, the combination with inherently rigid, continuous metallic arched girders open at their top and closed at their bottom or intrados faces, of a plurality of tieplates extending transversely thereto which are connected together at their edges and connected at their ends to the girders, and a backing of concrete-cement filling surrounding the upper parts of the girders and on top of the tie-plates. y

3. In an arched -bridge construction, an arched metallic frame comprising a number of IOO IIO

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#matite built-up arched metallic girders, and a coni crete filling or backing, the spandrels of said bridge having inserted horizontally-disposed -hollow cylinders to lighten the same.

tie-plates are embedded.

5. In a viaduct construction of arched bridges as herein described, the combination i in the concrete-cement filling or backing adapted to lighten the steady load on' the haunches, and compensating or tie rods extending in the concrete cement in a general horizontal direction in relation to the abutments and crown of the arch.

8. The herein described method of conA structing arched bridges Without the use of temporary false framework and laggingfor centering the same, which consists in,rst,pre paring the foundations; secondly, anchoring thereto, in successive ordena plurality of continuous and inherently rigid self-sustaining arched girders or ribs, adapted to sustain and carry the concrete as component parts of the metallic frame of the structure; thirdly, uniting said arched ribs laterally into a complete rigid arched frame by tie-plates or channels, and finally adding a concrete body portion to the rigid frame thus formed.

In testimony whereof I have hereunto signed my name in the presence of two subscribing Witnesses. v

SAMUEL W. HILL. In presence of- CLARENCE A. WILLIAMS, JOHN H. RONEY.

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