DK147860B

DK147860B - PRESSURE CABLE CONNECTION

Info

Publication number: DK147860B
Application number: DK146577A
Authority: DK
Inventors: Pierre Xercavins-Guarro
Original assignee: Freyssinet Int Stup
Priority date: 1976-04-05
Filing date: 1977-04-01
Publication date: 1984-12-24
Also published as: FR2347504A1; FR2347504B1; IT1076417B; JPS531924A; ES457514A1; IN147585B; JPS5832257B2; BE853233A; DK146577A; DK147860C

Description

147860147860

Opfindelsen angår en kobling til sammenkobling af to forspændingskabler i forlængelse af hinanden i en betonkonstruktion, og således at det ene kabel, såkaldt sekundært kabel, kan anbringes på plads, efter at det andet 5 kabel, såkaldt primært kabel, er blevet indsat i konstruktionen og sat under forspænding, og af den art, hvor det sekundære kabel er forankret i en del, der ved periferien er udformet med udskæringer, hvori er indsat det sekundære kabels dugter, hvis ender har forankringsstykker 10 i anlæg mod nævnte forankringsdel.BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a coupling for interconnecting two prestressed cables in succession in a concrete structure and so that one cable, so-called secondary cable, can be placed in place after the other cable, so-called primary cable, has been inserted into the structure and biased and of the kind in which the secondary cable is anchored in a portion formed at the periphery with cut-outs, in which are inserted the debris of the secondary cable, the ends of which have anchoring pieces 10 abutting against said anchoring part.

En kendt teknik ved konstruktioner af forspændt beton gør det muligt at bygge en kontinuerlig konstruktion i flere successive faser. Eksempelvis kan de enkelte brofag i en kontinuert bro støbes efter hinanden un-15 der anvendelse af et stillads og en forskalling, der har en længde svarende til brofagets længde, og som flyttes fra det ene brofag til det næste. Disse konstruktioner har sædvanligvis forspændingskabler, der strækker sig over hele længden af konstruktionen.A known technique for prestressed concrete structures enables a continuous construction to be built in several successive phases. For example, the individual bridge subjects in a continuous bridge may be molded one after the other using a scaffold and a formwork having a length corresponding to the length of the bridge subject and which is moved from one bridge subject to the next. These constructions usually have bias cables extending over the entire length of the structure.

20 Efter opførelsen af det ene brofag kan stilladset og forskallingen først genbruges efter at betonen er sat under forspændingen, dvs. først efter at kablerne eller dele af kablerne i det pågældende brofag er sat under spænding, hvorved det pågældende brofag får den fornød-25 ne styrke til at kunne bære sin egen vægt. Under opførelsen af de efterfølgende brofag og med henblik på kontinuitet i kablet, må et i brofaget forspændt kabel, såkaldt primær kabel, kunne forlænges med et kabelafsnit, såkaldt sekundært kabel, for det næste brofag, 30 hvilket kabel skal kunne sættes under trækspænding efter støbning af det pågældende brofag. Disse to kabelafsnit er forbundet med hinanden ved hjælp af en kobling.20 After the construction of one bridge section, the scaffold and formwork can only be reused after the concrete has been put under the prestressing, ie. only after the cables or parts of the cables in the bridging section are put under tension, thereby giving the bridging section the necessary strength to be able to carry its own weight. During the construction of the subsequent bridge compartments and for continuity of the cable, a cable pre-tensioned in the bridge compartment, so-called primary cable, must be able to be extended with a cable section, so-called secondary cable, for the next bridge compartment, which cable must be able to be put under tension after casting. of the bridge subject in question. These two cable sections are connected to each other by means of a coupling.

En sådan kobling omfatter en del til forspænding og forankring af det primære kabel, og en del til for-35 ankring af det sekundære kabel til det primære kabel.Such a coupling comprises a portion for biasing and anchoring the primary cable, and a portion for anchoring the secondary cable to the primary cable.

Den væsentligste ulempe ved koblinger af denne art er deres pladsbehov, idet den forankringsplade, der an- 2 147860 vendes til forankring af det primære kabel, også skal give tilstrækkelig plads til forankring af det sekundære kabels dugter, således at enhver forøgelse af diameteren af koblingen indebærer en kraftig forringelse af 5 den støbte betons styrke på det pågældende sted, såvel under den midlertidige fase inden indsprøjtningen i det sekundære kabel som under slutfasen, eftersom den indsprøjtede vælling langt fra har samme styrke som betonen i den resterende del af konstruktionen. Det kan også væ-10 re vanskeligt at placere samtlige koblinger på det pågældende sted, fordi der ikke er plads nok.The main disadvantage of couplings of this kind is their space requirements, since the anchor plate used for anchoring the primary cable must also provide sufficient space for anchoring the secondary cable ducts, so that any increase in the diameter of the coupling involves a significant deterioration of the strength of the cast concrete at that location, both during the temporary phase before the injection in the secondary cable and during the final phase, since the injected ripple has far from the same strength as the concrete in the remainder of the structure. It can also be difficult to place all the couplings in that location because there is not enough space.

Ved opfindelsen tilsigtes opnået en reduktion af diameteren af koblinger af denne art, hvilket indebærer en formindskelse af pladsbehovet i betonkonstruktionen 15 på det pågældende sted, og dermed en forbedring af styrken på dette sted.The invention aims at reducing the diameter of couplings of this kind, which implies a reduction of the space requirement in the concrete structure 15 at the site in question, and thus an improvement in the strength at that location.

Koblingen ifølge opfindelsen adskiller sig fra nævnte kendte kobling ved, at forankringsdelen har fast forbindelse med et aksialt, gevindskåret element indret-20 tet til fastskruning på det forspændte, primære kabels forankringsplade. Herved opnås, at nævnte dels yderdiameter kan tilnærmelsesvis være den samme som diameteren af forankringspladen for det primære kabel, og det er denne diameter der bestemmer koblingens reducerede yder-25 diameter.The coupling according to the invention differs from the known coupling in that the anchoring part has a fixed connection with an axial threaded element arranged for fastening on the anchoring plate of the prestressed primary cable. Hereby it is obtained that the outer diameter of said part can be approximately the same as the diameter of the anchor plate of the primary cable, and it is this diameter which determines the reduced outer diameter of the coupling.

I henhold til en hensigtsmæssig udførelsesform for koblingen ifølge opfindelsen, kan det nævnte gevindskår-ne element udgøres af en stang, der er skruet i bund i et bundhul i forankringsdelen.According to a suitable embodiment of the coupling according to the invention, said threaded member may be constituted by a rod screwed into a bottom hole in the anchoring part.

30 Medens forankringsdelen eksempelvis fremstilles ved støbning af stål og derefter bores og gevindskæres, kan det gevindskårne element bestå af trukket eller smedet stål, der giver større styrke end stålgods.While, for example, the anchoring member is manufactured by casting steel and then drilled and threaded, the threaded member may consist of drawn or forged steel which provides greater strength than steel material.

Opfindelsen forklares nærmere i det følgende under 35 henvisning til den skematiske tegning, hvor fig. 1 viser et længdesnit gennem en kobling af i og for sig kendt art.The invention is explained in more detail below with reference to the schematic drawing, in which fig. 1 shows a longitudinal section through a coupling of a kind known per se.

3 U7860 fig. 2 et længdesnit gennem en kobling ifølge opfindelsen , fig. 3 den med udskæringer udformede forankringsdel for det sekundære kabel, set fra enden, og 5 fig. 4 et længdesnit gennem en yderligere udførel sesform for forankringsdelen for det sekundære kabel.3 U7860 FIG. 2 is a longitudinal section through a coupling according to the invention; FIG. 3 is an end view of the anchoring member for the secondary cable, and FIG. 4 is a longitudinal section through a further embodiment of the anchor part of the secondary cable.

I den i fig. 1 viste kendte kobling omfatter det i den støbte del 1 af konstruktionen beliggende, primære kabel, et antal dugter 2, som er anbragt i en kappe 10 8, og som forankres til en forankringsplåde 3, der over en ring 5 støtter sig på en plade 4, som er indstøbt i beton. De enkelte dugter, som består af en tråd med stor indbyrdes brudstyrke eller et trådbundt er forankret i hver sin koniske åbning i forankringspladen 3 15 ved hjælp af klembakker 6. Åbningerne er fordelt langs en cirkel og pladen 3 omfatter et hul 7 til indsprøjtning af en beskyttende vælling i det indre af kappen 8.In the embodiment shown in FIG. 1, the primary cable located in the molded part 1 of the structure comprises a plurality of cloths 2 which are arranged in a jacket 10 8 and which are anchored to an anchor plate 3 which supports a plate 5 over a ring 5 4, which is embedded in concrete. The individual scents, which consist of a wire having a high mutual breaking strength or a wire bundle, are anchored in each of its tapered apertures in the anchor plate 3 15 by means of clamping trays 6. The openings are distributed along a circle and the plate 3 comprises a hole 7 for injecting a protective insulation in the interior of the sheath 8.

Langs sin omkreds har forankringspladen 3 et an-20 tal udskæringer 9, hvori indsættes enderne af de dugter 10, der indgår i det sekundære kabel. Ved enderne af disse dugter findes der bøsninger 20, hvori dugterne 10 forankres ved hjælp af klembakker eller ved fastklemning. Disse bøsninger støtter sig på sider-25 ne af udskæringerne 9 i pladen 3.Along its circumference, the anchoring plate 3 has a number of cut-outs 9 in which the ends of the cloths 10 included in the secondary cable are inserted. At the ends of these scents there are bushings 20 in which the scents 10 are anchored by clamping trays or by clamping. These bushings are supported on the sides of the cutouts 9 of the plate 3.

Hele koblingen er anbragt i et hus 12, hvori der efter at kablet er sat under trækspænding indsprøjtes en vælling af hærdbart materiale samtidigt med indsprøjtningen i kappen til det sekundære kabel.The entire coupling is arranged in a housing 12, in which, after the cable is put under tension, a curable material is injected simultaneously with the injection into the casing of the secondary cable.

30 Fig. 2 viser et primært kabel, der omfatter et an tal dugter 2, der er indsat i betonkonstruktionen 1 som er sat under forspænding. Kablet holdes adskilt fra betonen ved hjælp af en kappe 8, der gennem et konisk overgangsstykke 13 er forbundet med forankringspladen 35 14. Denne forankringsplade 14 støtter sig på en plade 15 som er indstøbt i betonen. Dugterne 2 i det primære kabel forankres ved hjælp af klembakker 16 i 147860 4 koniske åbninger, der er fordelt langs en cirkel i forankringspladen 14. Det primære kabel forspændes ved hjælp af en trykcylinder og forankres på i og for sig kendt måde.FIG. 2 shows a primary cable comprising a plurality of wires 2 inserted into the concrete structure 1 which is under tension. The cable is kept separate from the concrete by means of a sheath 8 which, through a tapered transition piece 13, is connected to the anchor plate 35 14. This anchor plate 14 is supported on a plate 15 which is embedded in the concrete. The rags 2 of the primary cable are anchored by means of clamping boxes 16 in conical openings distributed along a circle in the anchor plate 14. The primary cable is biased by means of a pressure cylinder and anchored in a manner known per se.

5 Forankringsdelen 17 for det sekundære kabel om fatter langs omkredsen en række udskæringer 18, hvori er indsat enderne af kablets dugter 10. På bagsiden har delen 17 et cylindrisk parti 19, der er gevindskåret, og som kan skrues ind i en gevindskåret aksial 10 åbning i forankringspladen 14 for det primære kabel.5 The secondary cable anchor portion 17 comprises a series of cut-outs 18 including the ends of the cable cloths 10. At the rear, the portion 17 has a cylindrical portion 19 which is threaded and can be screwed into a threaded axial 10 aperture. in the anchor plate 14 for the primary cable.

Ved enderne af dugterne 10 i det sekundære kabel findes der forankringsstykker 20, der støtter sig på delen 17 bag udskæringerne 18. Disse forankringsstykker 20 kan være af vilkårlig kendt art, såsom 15 f.eks. bøsninger med konisk åbning, hvori dugterne blokeres ved hjælp af klembakker, eller bøsninger, hvori dugterne fastklemmes som vist i fig. 2, eller ved udfladning af dugternes ender til dannelse af hoveder.At the ends of the tabs 10 of the secondary cable there are anchoring pieces 20 which are supported on the part 17 behind the cut-outs 18. These anchoring pieces 20 may be of any known kind, such as 15 e.g. conical opening bushes in which the dews are blocked by clamping trays, or bushes in which the dews are clamped as shown in FIG. 2, or by flattening the ends of the dews to form heads.

Koblingen er anbragt i et hus 21, der er udfor-20 met med en konisk overgang 22 til kappen 23, der omgiver det sekundære kabel. Et rør 24 tjener til udluftning ved påfyldning af det sekundære kabel og huset med en beskyttende, hærdbar vælling.The coupling is arranged in a housing 21 formed with a tapered transition 22 to the sheath 23 surrounding the secondary cable. A tube 24 serves to vent the filling of the secondary cable and housing with a protective curable ridge.

X henhold til en anden udførelsesform som er vist 25 i fig. 4, kan forankringsorganet for det sekundære kabel bestå af to dele, nemlig en med udskæringer udformet del 25 til forankring af det sekundære kabels dugter og en gevindskåret stang 26, der forbinder nævnte del med forankringsorganet 14 for det primære kabel.X according to another embodiment shown in FIG. 4, the secondary cable anchorage member may consist of two parts, namely a cut-out portion 25 for anchoring the secondary cable's lugs and a threaded rod 26 connecting said portion to the primary cable anchorage member 14.

30 I visse tilfælde kan det være hensigtsmæssigt at anvende koblingen ifølge opfindelsen uden huset. Bortset fra den besparelse man opnår ved afskaffelse af huset, har denne løsning den fordel, at koblingen vil blive indlejret i beton af samme kvalitet som i den resterende 35 del af konstruktionen, og hvis styrke er større end den styrke man opnår med den indsprøjtede vælling. Styrken ved koblingen vil derfor være større. I så fald må over-In some cases it may be convenient to use the coupling according to the invention without the housing. Apart from the savings achieved by the removal of the house, this solution has the advantage that the coupling will be embedded in concrete of the same quality as in the remaining part of the construction, and the strength of which is greater than the strength obtained with the injected vault. . The strength of the coupling will therefore be greater. In that case,

Claims

147860 the transfer of the tensile stress from the secondary cable to the primary cable is not stopped by the fact that the parts of the coupling are against concrete. Therefore, it is necessary to provide some leeway for a minor movement of the parts 5 in the axial direction of the two cables under the tension of the secondary cable. For this purpose, the individual parts included in the coupling may be coated with a layer of compressible material or with viscous grease prior to casting 10. For the purpose of injecting curable material into the sheath of the secondary cable, this sheath may be formed with a vent hole on the side facing the coupling. Such a clutch without housing is shown in FIG. 4. The scents of the 15 secondary cable are retained by means of a ring 27 at the place where the scents extend. The sheath 23 is closed by means of a plug 28 formed with a vent tube 29 through which the bulge can be injected into the sheath. 20

1. Coupling for interconnecting two consecutive bias cables in a concrete structure, 25 and so that one cable, so-called secondary cable, can be placed in place after the other cable, so-called primary cable, has been inserted into the structure and inserted under prestressing, and of the kind in which the secondary cable is anchored in a portion (17) formed at the periphery with cut-outs (18) into which are inserted the dowels (10) of the secondary cable, the ends of which have anchoring pieces (20) in abutment against said anchoring part (17), characterized in that the anchoring part (17) has a fixed connection with an axial threaded element 35 (19) arranged for fastening on the anchored plate (14) of the prestressed primary cable.