US1973742A - Arch construction - Google Patents

Description

Sept. 18, 1934. B BAUER ARCH CONSTRUCTION Filfid July 9, 1952 4 SheetsShet 1 Fig. 6

BrunaEauer INVENTO -I -Spt. 1a, 1934.

BAUER 1,973,742

ARCH VQONSTRUCTION Filed July 9, 1932 4 Sh'ets-Sheet 2 Fig. 2| v i INVENTOR:

Sept. 18, 1934. B. BAUER ARCH I CONSTRUCTION Filed- July 9, 1932 4 Sheets-Sheet 3 Sept.- 18, 1934.

' Fig. 40

-zumrro STATE-S oer-ice 1,973.74: linen oons'rauc'rron Bruno Bauer-fvienna, Austria Application July 911932, Serial 80.821394 In Auatrla' my 14, m1

' denim. (c1; ra -"m This invention relates to a newandimproved of embedding the iron frameworkin concrete as method of electing arches. 'Although it is an primarily intended, more particularly since with indisputable and generally recognized fact that the Melan archthe embedded iron framework the erection of a plain non-reinforced vaulted must be so dimensioned that the weight of the not arch or arched span is the most advantageous yet hardened concrete does not subject it to a 60 method of bridge construction, nevertheless this total strain greater than 600 kg/cln' in order type of bridging has to a constantly increasing that, after hardening of the concrete, this frameextent been supplanted by bridges constructed work may be eflfective as reinforcement withthe of iron or of ferro-concrete. Yet the simple remaining 600 kg/cm of its total resistance to m non-reinforced arched span, which the Rostress. I h mans are known to have built in concrete, is very The present invention provides a method of considerably less sensitive and more resistant to construction which is calculated to reestablish the strains to which it is normally subjected, and thepractical significance of the non-reinforced which especially in recent years are perpetually arched bridge whichhas been thrust into the on the increase in consequence of growing traflic background of modern practice, and thereby to 7 loads, than bridge constructions of iron or ferroafford the possibility of employing arched bridges concrete, in consequence of its great inherent which have very large reserves of bearingweight relative to the traflic load. Innumerable strength, and which can therefore be erected to arched bridges, which were built hundreds of stand for longer periods than the sorapidly age-' years ago, are still in service unaltered to-day, and ing iron and ferro-concrete bridges. The pres-- 75 will carry the heaviest motor trucks and tanks, entinvention'makes it unnecessary to incur heavy whereas iron bridges erected at enormous expense costs which ordinarily accompany the construcscarcely or years ago demand replacementtion and erection 'of scaffolding and other. ar- 0 Strengtheniit- In spite of these facts the rangements for the purpose of supporting the 25 building of non-reinforced concrete bridges has weight of the fresh concrete duringits setting 0 gene almost Completely Out Of recognized p actice, and shaping operations. It is precisely this necesand that more particularly for the reason that sity for making the scaffolding and falsework their erection calls for expensive scaffolding and absolutely proof against deformation and shifting falsework which must be charged to overhead which gives rise to their enormous cost, more pareosts. and which Often account for more than half ticularly in view of the necessity for their erec-.- the building costs. tion in running water.

It has therefore become the practice to build The constructional method according to the idem a s of reinforced ncret This present invention enables the bridging work to method of construction permits of very considerb i d t i stages, with the aid of easily able reduction of the'dead weight of the struct d etal heets, commencing in narrow ture and therefore 8180 Of the outlay for SCflfiOldstrips the procedure being such that a self-supin a d fa w o ev pe its, a i the ease porting, stable, and rigid templet mould formed of rein o emen din t0 the M61811 System, of steel is provided, before the concreting work of Scaffolding being t y di5pel15ed with a is begun. Although the supporting structure for of thefalsework sh in being suspend r the iron templet mould remains in the completed th mf s f r a m w o r k. r n r structure, it cannot be regarded as reinforcement, arches erected and reinforced in this manner are a d ti11 l be separately charged for, since in dimensioned, however, like iron bridges, merely th i t rest of easy and cheap. building it must for the trafllc load for which they-are calculated, be so lightly dimensioned that its carrying and thus form bridge constructions which have strength is just sufiicient to suppert one or two no traflic load reserve. The-constructions built longitudinal sections or arching before setting. aeeol'ding '6 the Melan ys ave t e fu Only after the setting of such section or sections, disadv n a e of being very expen ive. nce their which form but a fraction of the full breadth of st is mad up f tw mponents each of which the bridge, is the remainder oi. the bridge"%uilt.

50 alone almost amounts to the cost of a bridge con- For this purpose the carrying capacity of the secstruction, The iron framework embedded in the tions first built is utilized in conjunction with the Melan arch would not require to be strengthened templets of the not yet embedded trellis-work of very much to constitutein itself an iron bridge. the carrying construction which project bracket- The necessary cost of strengthening would probafashion from the already set arch section or sec- 55 bly as a rule be even less than the additional cost tions. The principle of this progressive method/ of construction can be compared to that of the method by which heavy mooring ropes or chains are brought on land from ships. For this latter purpose a wooden ball is first thrown out to" which there is attached a thin cord. To this cord there is then tied a heavier rope, and to this rope there is finally fastened the mooring chain which is to be hauled on land. By-the method indicated above, and to be described in detail below, it is possible to erect without scaifolding, i. e. in suspension, a relatively very light and cheap bridging in the form of sheet metal falsework which gradually loses its carrying capacity completely as the concreting work proceeds by stages, while the carrying capacity of the bridging arch itself arises by the same stages.

It is immaterial to the principle of the invention whether the portion of the arch first produced is a longitudinal section or strip bounded by vertical planes or an arch shell of a thickness equal to a fraction of the thickness of the finished arch. In every case the section or shell of the arch first made by the pouring of concrete or by the laying of cut stone or bricks is utilized in conjunction with the trellis-work as a carrying structure for the templeting for the remaining sections or shells of the arch.

Since, according to-the span of the bridge, it

will not always be suflicient to use a single trelliswork of the type already known from the Junkers system of roof construction, it will be necessary under certain circumstances to provide three-dimensional trellis-work. The three-dimensional trellis-work provided for this purpose by the present invention represents in itself a new invention.

Several forms of construction embodying the invention are illustrated, by way of example, in the accompanying drawings, in which:

Fig. 1 shows diagrammatical and in longitudinal section, an element of the network with the templet sheeting attached thereto.

Fig. 2 is a section taken on the line BB of Fig. 3 through a part of the erecting equipment, corresponding to the length of the reinforcing skeleton for the bridge arch.

Fig. 3 is a transverse section taken on the line AA of Fig. 2.

Fig. 4 is a side elevation of a portion of the arc-shaped erecting equipment.

Fig. 5 is a section taken on the line C--C of Fig. 4.

Fig. 6 is a cross-section through a reinforcing skeleton with the connection through the trusses, on an enlarged scale.

Fig. '7 shows diagrammatically, and in perspective view, a simple network of sheet steel strips, the possibly necessary reinforcing members and also the templet sheeting being indicated.

Fig. 8 is a perspective view of a three-dimensional trellis-work of strips, the points of support of the two superposed courses of sheet steel strips being interconnected, and arrangements being on these spindles.

to the network a of sheet steel strips both on the upper and on the lower side. The upper reinforcing skeletonsare connectedto the lower reinforcing skeletons by means of bracing :c. The templet sheeting required for the concrete work is denoted by 0. I

In the forms of construction shown in Figs. 7 to 10, the lower or only network is denoted by a, the upper network by b, the nodes or points of support by c, and the substantially vertical stay strips for the interconnection of superposed points of support by d. The three-dimensionally diagonal ties used in the forms of construction shown in Figs. 9 and mate denoted by e, and the diagonal ties disposed in the plane of the rhombi of the network by. f.

If desired, special reinforcing irons can be provided which, are disposed in the direction of the axis of the bridge.

A form of construction of this nature is illustrated diagrammatically in Fig. 7. The connecthand to double-T girders l, and on the other hand to stays m. The girders Zare provided'with' longitudinal slots p in which reinforcing irons n are inserted. In this manner it becomes possible to set the reinforcing irons in the required position determined by leveling. 1

As templet sheeting corrugated sheet 0 is used which is likewise preferably arranged to be adjustable as to level. i

In the form of construction shown in Fig. 8, the supporting points of the two superposed networks are connected on the upper side and on the under side with plain U-section ironsg. In order to enable the templet sheeting k to be adjustable as to level, screw-threadedspindles h are provided on the fish-plates joining the stripsat their points of mutual contact, and nuts 2' are provided The templet sheeting it rests upon these nuts and can be raised and lowered thereby. Separate reinforcement is unnecessary in this form.

In accordance with the invention the trelliswork supporting the sheeting is made only of such dimensions as are required to enable it to carry the dead weight of the wet concrete.

The described trellis-work is suitable for use in connection with simple concrete work, for

ferro-concrete arching, and also for arch con-- struction in stone.

The erection of the alternative for scafiolding and falsework provided by the present invention is effected by assembling one half of the span on each bank of the river or the like to be bridged, swinging the two parts towards each other by means of suitable tackle, and connecting them up in the middle. The assembling can also be effected from three separate parts. The trelliswork constitutes the carrier for the sheeting which is preferably made of chequer plating, corrugated sheet, or the like. The sheeting, which can be cleaned either before mounting or after dismaning or supporting points 0 are tied on the one as to be adjustable, and that preferably in a vertical sense. When the sheeting has been positioned the preparations for-the pouring of theconcrete are completed. I claim: i *1. In an arch 'construction,- a templet, and a carrier for said teinplet, both forming a permanent part of the construction, said carrier consisting of a trelliswork of sheet metal strips supported'edgewise and each of said strips having its upper and lower edges bent over at right angles.

2. A templet carrier according to claim 1, characterized by a plurality of superimposed trellisi 1,973,742 tling, is suitably attached to the lattice-work so,

nodes, and stay strips interconnect--

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