US1327889A - Concrete structure - Google Patents

Description

W. M. THOMAS. CONCRETE STRUCTURE.

APPLICATION msn Nov. 22, 191s.

31,327,889. y Patented Jan. 13, 1920.

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W. M. THOMAS.

CONCRETE STRUCTURE. APPLlcATloN FILED Nov. 22. |915.

Patented Jan.13,1920.

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APPLICATION FILED NOV. 22| i915.

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W. M. THOMAS.

CONCRETE STRUCTURE.

APPLlcAnoN FILED Nov. 22. 191s.

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WILLIAM 1VI. THOMAS, OF LOS' ANGELES, CALIFORNIA.

CONCRETE STRUCTURE.

Specification of Letters Patent. v Patented J 3.11. 13, 1920.

Application led November 22, 1915. Seriall No. 62,689.

To all whom t may concern Be it known that T, vWILLIAM M. THOMAS, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Concrete Structures, of which the following is a specification.

Tn general an object of this invention is to produce concrete structures having maximum strength with a minimum amount of material.

Another object is to produce a construction of this character in which the material is distributed to the best advantage in the structure to obtain the desired strength at the different parts of the lstructure in accordance with the strains to which said parts are subjected.

Another object is to make provision in concrete structures whereby the distance between the intrados of the arch and the surface of the roadway or deck is minimized.

Another object is to produce a concrete arch construction having minimum rise and maximum strength. l

Another object is the production of concrete structures wherein the roadway or deck slabs at the crown of the arches are of integral construction with said arches so that in making the calculations for the arches said roadway slabs can be figured as parts of the arches.

Another object is to produce a concrete bridge construction whereby dirt fills may be avoided, thus requiringlighter construction of the piers, pier foundations and superstructure than in prior bridge constructions of concrete designed for the same live weight.

The accompanying drawings illustrate several forms of the invention embodied in bridge spans or bents.

Figure 1 is an elevation partly in section on line indicated by Q01-w1, Fig. 2, of a span or bent of an arch bridge built in accordance with this invention.

Fig. 2 yis a .plan view of the span `shown in section in Fig. 1.

Fig. 3 is a perspective view of a fragment of the span in Figs. 1 and 2 showing two adjacent preformed arch' sections and one of the preformed floor slabs mounted in position on one of the arch sections.

Fig. A is perspective View .of a fragment of a modified form of .span .showing .two adjacent preformed arch sections and a preformed Hoor slab mounted between the flanges of said arch sections.

Figs. 5, 6, 7 and 8 are enlarged transverse Fig. -9 is yan enlarged end elevation of Figs. 1 and 2, omitting the piers.

Fig. 10 is a side-elevation of a modified l form of preformed arch lsections mounted on their abutments. f

Fig. -11 is a transverse section on yline indicatedA by @#xl Fig. 110, the temporary forms for molding the floor structure n `stm also being shown together with a section of the floor or deck.

Fig. 12 is a vertical section on line indicated by can-w12, Fig. 4.

Fig. 13 is an elevation .of the crown end` of one` of the arch segments showing the ball and .the socket member. Y

Fig. 14 is a fragmentary vertical section of a monolithic structure embodying the invention.

There are provided arches whichmay -be of the ,three-hinge type each comprising complementary longitudinally alined arch sections or segments l, 2 joined together at their upper or crown ends by a suitable hinge, said hinge in the drawings-.being formed of socket membersl 3 and .a ball L and said arch sections having their lower or thrust ends seated on suitable supports fas,v

of said arclimenibers also comprises upper laterally extending flanges 9 yextending from the crown 8 a substantial distance vtoward the pier and-cast integral with the arch member y7. Thus the arch members at the crowns are of rectangular cross vsection as in Fig. 5 and between the crowns ,and the pier hinges' are T-shaped in cross section. Between the flanges 9 :and the piers said arch members 7 are rectangular in cross section and' the spandrel .spaces l0 are Open as curved faces of the members 7 and on are also the spaces 11 between transversely adjacent arch members.

"lhe arch segments 1, 2 may be cast a situ, or the arch segments may be preformed. The flanges 9 may be either preformed as integral parts of the arch sections l, 2 before emplacement of said sections (and this is desirable for smaller structures), or the flanges 9 may be cast n situ on the arch members 7, and this is especially desirable for larger structures. The arch members 7 as in Figs. 10 and 11 when preformed are provided with reinforcement members forming cages 12 cast in said arch members and projecting from the adjacent ends and above the extrados of vthe arch members and to said cages are secured the hinge socket members 3.

The crowns 8 and the curved members 7 are made of sufficient thickness so that they `together with the flanges 9 considered in the computations of the arch segments will withstand the pressures for which the structure is designed and the flanges 9 extend from the crowns to the points where the vupper curved surface of the curved mem- `be'rs 7. The floor 16 may be cast a sz'zu` or may be constructed of preformed archshaped or T-shaped slabs 18 some of which extend longitudinally and seat at their opposite ends respectively in seats 19 at the points of meeting of the flanges 9 and upper the transverse supports 17. 1

The flanges 9 may be of suflicient width so that the flanges of two adjacent arch segments transversely of the structure may have their adjacent. edges united by grouting 20 as in Fig. 2 or, if desired, said arch segments may be spread apart from one another to leave a space of suicient width for the insertion of another or other of the T-shaped slabs 18 as in Fig. 4, the opposite ends of said other slabs being seated respectively on transverse beams k21 joining the adjacent crowns S to one another, and on transverse beams 22 of the supports 17.

Still other of the slabs 18 as in dotted lines in Fig. 4 may have their opposite ends seated on the transverse beams 22 respectively. The upper surface of said slabs 18 are flush with the upper surface of the flanges 9 and said slabs are fastened in place by suitable anchors 23 which may be in the form of steel rods projecting up from the seats 19, and transverse supports 17 and extending into sockets 24 in said slabs.

The flanges 9, as in Fig. 3, and said flanges and some of the slabs 18, as in Fig. 4, may be anchored to one another by rods 25 extending through holes 26 and coupled together by turn buckles 27 or equivalents which are accommodated in recesses 28 formed in the edges of the anges.

From the foregoing it is seen that the arch segments 1, 2 have flat flanged extrados portions forming a portion of the floor or deck of the structure and that in consequence of the crowns 8 of rectangular cross section and of the flanges 9 the arch segments may be made of minimum thickness at the crown of the arch and also that I ani enabled thereby to construct an almost flat arch without diminishing the head space beneath the arch, and that the height of lthe floor or deck above the surface of the stream or thoroughfare running beneath may be re duced to a minimum.

It is also seen that when the T-shaped slabs 18 form the other portions of the floor' or deck of the structure the ribs 29 of said slabs rest on their supports and that in consequence the adjoining flanges 30 of any two adjacent slabs transversely ofthe structure as in Fig. 3 and any two adjoining flanges 9, 30 as in Fig. 4 together function as an arch so that part of the load imposed on said slabs will be transmitted from slab to slab and thence to the supports.

In practice for a monolithicstructure castl a sim suitable forms, not shown, will be constructed to give the required shape of the various parts and suitably prepared concrete will be poured in the forms to produce the arch segments 1, 2 and floor 16 supported by the transverse supports 17 so that the spandrel spaces 10 and the spaces 1.1 between the transversely adjacent arch members 7 will be present.

In practice with the form of the invention in Figs. 1 to 3 the preformed arch segments 1, 2 and the preformed slabs 18 will be cast and seasoned at a convenient place by means and methods well known in the art and said segments will then be swung into place by any approved means with their lower or thrust ends resting on the piers 5 and their upper or crown ends connected to one another by the hinge members 3, 4.

1t is noted that the ball and socket members permit of perfect seating of the arch segments on the abutments independently of one another so as to avoid the production of unforeseen stresses in said segments when said segments are being mounted on their jacent flanges of the slabs 18 and into the recesses 28, thus firmly bonding the various parts together.

With, the form of the invention shown in lFig. 4L the preformed arch segments 1, 2 will be cast as stated above and will be erected in position with the flanges 9 spaced apart from one another and then one or more of the preformed slabs 1S will be inserted in the space between adjacent fianges 9, and other of the slabs 18 will be placed in position to complete the deck and then the grouting 20 will be poured into the joints between the flanges and into the recesses Q8.

lVith the form of the invention shown in Figs. l0 and 11 the arch members 7 will be.

cast and seasoned at a convenient place by means and methods well understood in the art with the reinforcement cages 12 cast in said members and then said members will be swung into place by suitable means with their thrust ends resting on the piers 5 and their crown ends joined by the hinge members 3, 1.

Then a temporary structure 29 constituting forms will be erected between adjacent arch members.

Then a suitable mixture of concrete will be poured into the forms and leveled off to form n situ the flanges 9 which constitute a portion of the roadway or deck, and the preformed slabs 18 willthen be placed in position as above stated to extend the roadway or deck from the flanges 9 to the ends of the structure. After the requisite interval of time has elapsed for hardening of the flanges 9, the forms 29 will be removed, leaving the flanges intact as integral parts of the segments 1, 2.

It is noted that the structure produced as above described comprises arch members having their extrados forming a portion of the deck, transverse supports mounted on the arch members, and another portionV of the floor mounted partly on said arch members and partly on the transverse supports, the spandrels and the spaces between transversely adjacent arch members being open.

It is noted further that the foregoingdescribed construction .produces an elastic structure that is substantially as strong as though it were a monolith without having the inherent defects of the monolithic construction, for it is readily understood that a monolithic structure is subjected to un-y calculated strains due to expansion and contraction under varying temperatures and to the tension-producing eEects of live loa'd on the structure. It is clear that though the units of the floor are preformed, said oor is as strong as though it were cast n situ and yet is independent of the floor-supporting members so that live load on the floor Will be transmitted by the Hoor units with compressive arch effect to the supporting members, and therefore said load will not ports, the spandrels and the spaces between transversely adjacent arch members being open.

2. ln combination, preformed arch niembers having crowns of rect-angular crosssection and having a portion of their extrados forming a portion of a deck floor, transverse supports extending up from the arch members,v and another preformed portion of the floor mounted partly on said arch members and partly on the transverse supports, the spandrels and the spaces between transversely adjacent arch members being open.

3. A bridge comprising longitudinally extending` preformed arch members having transverse supports, and a floor formed partly by ythe extrados of the preformed arch members and partly by preformed slabs resting on the transverse supports, the spandrels and the inter arch spaces being open. j

4:. In combination, preformed arch segments having curved members and laterally extending flanges integral with said curved members to form a deck portion, transverse supports extending up from said arch segments, and preformed slabs seated on the arch segments and on the transverse supports and having their upper faces flush with the upper faces of said flanges to form another deck portion. i

5. In combination, preformed arch segments each having a flat extrados portion to form a deck portion, preformed slabs each seated at one end on the arch segments adjacent to and having their upper faces flush with the flat extrados portion, and transverse supports extending up from the arch segments to support the other ends of said slabs.

6. In combination, preformed arch segments, each having a flanged extrados portion to form a deck portion, preformed slabs, each seated at one end on the arch segments adjacent to and having their upper faces flush with the flanged extrados portion to form another deck portion, and preformed transverse supports extending up from said arch segments to support the other ends of said slabs.

7. In combination, preformed arch segments, each having a flanged extrados portion to form a deck portion, preformed T- shaped slabs, each seated at one end on the arch segments adjacent to and having their upper faces flush with the flanged extrados portion to form another deck portion, and transverse supports extending up from said arch segments to support the other ends of said T-shaped slabs.

8. In combination, preformed arch segments, each having a flanged extrados portion to form a deck portion, and preformed T-shaped slabs having their upper faces Hush with the flanged extfados portion to form another deck portion.

9. In combination, preformed arch segments, each having integral flanged extrados portions to form a deck portion, the flanged extrados portions being spaced from one another, and preformed T-shaped slabs having their upper faces flush with the anged extrados portions, some of said T- shaped slabs extending in alinement with the anged extrados portions and other of said T-shaped slabs extending between adjacent flanged extrados portions -to form other deck portions.

10. In combination, piers, preformed arch segments hinged to one of said piers, other preformed arch segments hinged to the other pier, hinge members connecting the first arch segments to the other arch segments respectively, said arch segments having integral ianged extrados portions to form a deck portion transverse supports on the arch segments, and preformed T-shaped slabs supported by the arch segments and said transverse supports with their upper faces flush with the fianged extrados portions to form other deck portions.

ll. In combination, preformed arch members having their crown portions T-shaped in cross section and flat on the upper surface to form portions of the floor of a bridge, supports extending up from other portions of the arch members, and preformed T-shaped slabs having their inner ends seated on the arch members in alinement with the T-shaped portions of the arch members and having their outer ends seated on the supports to form other portions of the floor of the bridge.

In testimony whereof I have hereunto set my hand at Los Angeles, California, this 16th day of November, 1915.

f GEORGE I-I. HILEs,

A. F. SGHMIDTBAUER.

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