EP1008691B1 - Externally prestressed concrete bridge - Google Patents

Description

The invention relates to a concrete bridge with the features of the preamble of Claim 1.

So far, concrete bridges have been used generally with external prestressing or Preload created in the composite. The external bias, i.e. the provision free tendons or guy lines, preferably inside one Carrying body of the bridge, for example, takes place when creating the bridge in the Tact shift method use. Due to the peculiarity of this procedure However, a relatively small number of stays is sufficient. Because in general is the length of the individual section lengths between two abutments or supports relatively low, so that the Tension forces are small. Such a concrete bridge is described in DE 42 13 986C.

In contrast, it is for example when creating concrete bridges outdoors Stem required to brace the individual bridge sections so that the much greater forces to support or stabilize the bridge or the individual sections from the guy lines. This results in a high number of guying, which with the increase of Bridge length between two supports increases. In this case, the Up to now, bracing has usually been done in the carriageway slab or in the side walls concreted. However, there is considerable uncertainty about the Area of influence and action of the guy lines in the completed bridge. The crucial disadvantage is that there is none on the finished bridge Checks on the actual load-bearing capacity of the respective guy as well as any damage or overloading of the parts of the finished bridge Anchoring forming the entire structure are possible, with particular in Damage in the concrete body a corrosion attack on the guy lines, e.g. B. by de-icing salt applied to the bridge becomes possible. Embedded guy lines must be prepared and installed from the start of construction.

The use of external preload on bridges with a large free length between two supports, especially when creating such bridges in the free stem, has hardly been considered for reasons of cost. This resulted among other things from the difficulties with the orderly management and installing the high number of guy lines required in this case resulted.

The object of the invention is therefore to a concrete bridge with external prestress create, which also has a required high number of guy lines the least possible effort can be realized. This applies to both Manufacture of the fastenings and guides required for clamping as also for the actual installation of the guy lines.

This object is achieved by the combination of the features of claim 1.

By guiding the guy lines according to the invention within the free space of the support body will be guyed used to protect against corrosion to increase durability and this guy can also be checked continuously and if necessary to be repaired or replaced. In addition, it becomes possible to use the guy lines to be installed in areas where their load-bearing capacity is optimal for achieving the load capacity of the bridge can be used.

By the provision of bracing in a fixation and / or Guide area are arranged essentially next to each other and that Provide the longer stays in each case at a greater distance from the side wall of the supporting body of the bridge as the adjacent one shorter guying is achieved that a high number of guying in Essentially the same level or with essentially the same course can be performed, the optimal for structural reasons or a represents at least advantageous course. If necessary, several can be used Layers of guy lines arranged in this way are provided, which are arranged one above the other at least in the fixing and / or holding area.

This way of arranging or guiding the guy lines can also ensure that only a small number of deflections of the Bracing is required. Because every redirection reduces efficiency bracing or requires additional effort.

As far as possible, the distance between the stays in the fixing and / or Guide area and the longitudinal spacing of the pilaster strips for fastening the ends of the Guyings selected so that the guyings are as straight as possible, i.e. without Redirection run.

If this is no longer possible for constructional reasons, then two adjacent stays longer stays preferably only one redirected only once, namely in the area between the concerned Fastening list and the fastening list for the adjacent shorter one Guying. For this purpose, separate deflection means can either be provided or the pilaster strip, to which the adjacent shorter guying is attached at the same time to redirect the adjacent longer guying. Latter Possibility offers the advantage of an extremely low outlay, since guide means for guiding the guying to be redirected directly into the pilaster can be and no separate component is required.

This type of redirection in the area between the relevant neighboring Pilaster strips or by the fastening pilaster strips of the neighboring shorter ones Bracing allows the bracing to be close even in the overall course to each other and to each side of the bridge substantially parallel.

This way of guiding external guy can be done for practically everyone Bridge constructions are used, which are designed as a box girder Have support body, regardless of the manufacturing process for the support body and the number of stays. Of course it turns out Construction according to the invention is particularly advantageous if a high number of stays is required, especially for bridges, which are created in the free stem.

In the case of bridges created in the free stem, the fixation and / or is located Guide area preferably in a bridge section above a support, wherein on both sides of this central section each have opposite sections are provided. The guy lines are then preferably with their two Ends attached to pilaster strips in the opposite sections, the Fixing and / or guiding area in this case only for guiding or redirecting serves. Of course, it would also be possible to end each one Attach the guying in the fixing and / or guiding area. this is also valid regardless of the manufacturing process for the supporting body.

When creating the bridge in the free stem, upper braces in the essential the task that lined up in the free stem Keep bridge sections during the stem and in the final state. to The desired overall strength of the bridge is subsequently achieved lower guying is also required. According to the invention, it can be provided here the lower guy lines leading in the field between two supports are close and above the bottom plate of the box girder at least for the most part are led side by side to the pilaster strips that receive them.

It is for an optimal utilization of the load-bearing capacity of the guying desired that this be as close as possible to the ceiling of the box girder be carried out in progress. On the other hand, the pilaster strips must have a specific one Minimum distance between their lead-through openings for the associated guy lines from the ceiling. In order to still have a top guide close to the ceiling To ensure guy lines, the top guy lines are according to the invention receiving pilasters block-shaped and can be on their in the Box girder facing inside above the receptacle for the assigned Bracing near the ceiling is the bracing of the next bridge section have outwardly and preferably also downwardly deflecting guide. This also applies to the guy lines and the associated pilaster strips on Bottom of the box girder.

According to a development of the invention, the block-shaped pilaster strips are formed as prefabricated prefabricated parts, with anchors equal to these finished parts or anchor connections for connection to the supporting body of the bridge can be. The main advantage of prefabricated prefabricated parts is that that these have their full strength already when they are attached and because of the factory production are immediately available. Depending on the design of the The pilaster strips can be bridged at those that reject the respective support Ends of the bridge sections or within the length of each Bridge section, e.g. B. in the middle. The finished part pilots can also be used with other concrete bridges if e.g. B. a bridge is produced in the cycle shift process, wherein, preferably in Abutment area, a relatively large section of bridges by factory manufactured, pushed out with the help of presses and after manufacture of the next one larger section is pushed with this. Here are the pilaster strips External tensioning cable attached in sections is used to hold the device. Also with others, e.g. B. on a scaffold bridge bodies are Pilasters can be used to hold guy lines.

Further embodiments of the invention result from the subclaims.

Fig. 1-3

in schematischer Darstellungsweise jeweils in Draufsicht die Anordnung oberer Abspannungen über einer Stütze bei Baubeginn, nach einer Teilfertigstellung und schließlich nach Gesamtfertigstellung, wobei die Abspannungen nur als Linien angedeutet, die Lisenen nur in ihren Umrissen gezeichnet und die einzelnen Brückenabschnitte bei abgenommener Fahrbahnplatte angedeutet wurden,

Fig. 4, 5

in den Fig. 1 bis 3 entsprechender Darstellungsweise Seitenansichten zu Fig. 2, wobei nach Fig. 4 eine Umlenkung der Abspannungen zur Seitenwand und nach unten erfolgt und nach Fig. 5 die Abspannungen aus je zwei übereinander angeordneten Elementen bestehen, die an der jeweils vorletzten Lisene nur nach außen abgelenkt werden,

Fig. 6

einen Querschnitt durch die fertiggestellte Brücke im Bereich der Feldmitte zwischen zwei Stützen und

Fig. 7

einen entsprechenden Querschnitt der fertiggestellten Brücke über einer Stütze.

The invention is explained below with reference to an embodiment of a concrete bridge in the free porch shown in the drawing. The drawing shows:

Fig. 1-3

in a schematic representation, in each case in plan view, the arrangement of upper guy lines above a support at the start of construction, after partial completion and finally after total completion, whereby the guy lines are only indicated as lines, the pilaster strips are only drawn in outline and the individual bridge sections are indicated with the road slab removed,

4, 5

1 to 3 corresponding representation side views of Fig. 2, wherein according to Fig. 4 a deflection of the guy lines to the side wall and down takes place and according to Fig. 5 the guy lines each consist of two superimposed elements, each of which is penultimate Pilots are only distracted to the outside,

Fig. 6

a cross section through the completed bridge in the field center between two supports and

Fig. 7

a corresponding cross section of the completed bridge over a column.

The concrete bridge in question has over the existing one Support a central section 1 erected in the first construction phase, on which successively opposite other bridge sections 2, 2a, 3, 3a, 4 etc. in the open Stem can be attached using appropriate formwork. The Middle section 1 above a support is shown in cross section in FIG. 7. Fig. 6 shows a bridge section 5 also built in the free porch in the middle of the field between two supports. Each section 1-5 forms a box girder, the Ceiling consists of the slab 6. The bottom of the box girder was 7 and the side walls designated 8.

In the area of the bridge section 1 there is a holder or a fixing and / or Guide area 9 for upper guy attached, while the Bridge section 5 in the middle of the field below a bracket 10 for lower bracing receives.

To take up the guy lines are at the end of each bridge section Mounted pilasters 11, the inside 12 a guide and in the area of a Paragraph 12a of FIG. 4, an additional deflection for each to the next Form section guided guying. The pilaster strips for lower guying were designated 13 in FIG. 6.

After the middle section 1 has been set up, the two are initially the same Bridge sections 2, 2a erected in an appropriate formwork, the Embodiment at the ends of the bridge sections 2, 2a, the pilaster strips 11 attached and connected via spanned guy lines 14. at The pilaster strips can also be varied within the length of the bridge sections be provided. After completion of sections 2, 2a, the Sections 3, 3a lined up and with each other through the fixing and / or Guide area 9 guided guy lines 15 connected to the pilaster strips 11 of sections 2, 2a are diverted to their pilaster strips. The top Guyings 16 of sections 4, 4a are on the pilaster strips 11 of sections 3, 3a redirected and so on, so that finally in the area of the support from FIG. 3 apparent arrangement of the guy lines 14 - 16 and the following Bracing 17 is present, this and the from the guying 16 Guyings 17 are guided essentially parallel to each other. Fig. 5 and 7 show that for the same section there are also two superimposed Guyings, e.g. B. 15 can be performed, which then in one another arranged brackets of the pilaster strips 11 on the corresponding section recording Find. Also several guyings arranged one above the other for the same Section are possible with both lens types.

If a bridge field is already finished, the stem of starting from this only on one side, then within this finished the anchorage for the individual stays are to be provided. If the bridge is arched, you will be in the area of An additional fixation and / or guide area or guide device for deflecting the guying arrange in the bridge arch.

In the middle of the field, lower bracing 18, 19, 20 are attached, which here from the Starting from the middle of the field, connect the opposite bridge sections, the Guyings 18, analogous to guyings 14 in FIG. 3, guyings 19 seen from the center of the field analogous to the guy lines 15 above the support and finally, the guy lines 20 are ranked analogously to the guy lines 16, 17 are so that the guy image in the section of FIG 3 is similar. Can between the support and the center of the field also some sections of both upper stays 17 and lower Guy 19 or 20 can be reached.

The pilaster strips 11, 13 are preferably prefabricated in the factory and can therefore, since they have their full strength, those that occur immediately after installation Anchoring forces are transmitted.

Claims (12)

1. A concrete bridge

   a) comprising a support body (6, 7, 8) taking the form of a box girder which is prestressed by means of exposed bracing elements (14-20) provided in the interior of the box girder,

   b) at least one end of the bracing elements (14-20) being attached in each case to piers (11) rigidly connected to the support body (6, 7, 8) inside same,

   characterised in that

   c) in one or more zones of the bridge a plurality of bracing elements (14-17) are arranged substantially side-by-side in a fixing and/or guiding zone (9) inside the bridge zone concerned,

   d) the plurality of bracing elements (14-17) having in each case, with increasing distance from one of the outer side-walls (8) of the support body, a greater length between the fixing and/or guiding zone (9) and the corresponding end of the bracing element than the adjacent bracing element in the direction towards the side-wall (8) concerned, and

   e) the piers (11) for fixing the ends of the bracing elements (14-17) are joined to or at least arranged close to the corresponding side-wall (8).
2. Bridge according to Claim 1, characterised in that for at least some of the bracing elements (14-17) the distance between two adjacent bracing elements (14-17) in the fixing and/or guiding zone, seen transversely to the support body (6, 7, 8), and the distance between the piers (11) for fixing the corresponding ends of these bracing elements, are so selected that at least the bracing element having the greater length is disposed rectilinearly between the corresponding pier and the fixing and/or guiding zone.
3. Bridge according to Claim 1 or 2, characterised in that for at least some of the bracing elements (14-17) the distance between two adjacent bracing elements (14-17) in the fixing and/or guiding zone, seen transversely to the support body (6, 7, 8), and the distance between the piers (11) for fixing the corresponding ends of these bracing elements, are so selected that at least the bracing element having the greater length is disposed rectilinearly between the pier (11) for fixing the shorter adjacent bracing element and the fixing and/or guiding zone, and is deflected towards the side-wall concerned in the zone located substantially between the piers (11) for fixing the longer and shorter bracing elements.
4. Bridge according to Claim 3, characterised in that the pier (11) for fixing the shorter bracing element (14-17) serves at the same time to deflect the adjacent longer bracing element.
5. Bridge according to any one of the preceding claims, characterised in that the piers (11) have a block-like configuration and have on their inner face oriented towards the interior of the box girder (6, 7, 8), above the receptacle for the associated bracing element (14-17) and close to the roof, a guide element (12) which deflects the longer adjacent bracing element outwardly and preferably also downwardly.
6. Bridge according to any one of the preceding claims, characterised in that the support body consists of a plurality of sections.
7. Bridge according to Claim 6, characterised in that the sections are manufactured by the cantilever method.
8. Bridge according to either of claims 6 or 7, characterised in that a centre section (1) and, on each side thereof, diametrically-opposed further sections (2, 2a; 3, 3a, etc.) are provided above a support.
9. Bridge according to Claim 8, characterised in that the fixing and/or guiding zone (9) is provided in the centre section close to the underside of the roof (6) of the box girder.
10. Bridge according to any one of the preceding claims, characterised in that the bracing elements (14-17) are only fixed and deflected in the fixing and/or guiding zone (9) and the ends are fixed in piers (11) on both sides of the fixing and/or guiding zone, or in that one end of the bracing elements is fixed in each case in the fixing and/or guiding zone or in a previously manufactured section of the bridge, this being the case with any disposition of the bracing elements.
11. Concrete bridge according to any one of claims 6 to 10, characterised in that lower bracing elements (18-20) disposed across the midspan between two supports are guided to the piers (13) receiving them close to and above the floor slab (7) of the box girder (6, 7, 8) and at least predominantly side-by-side.
12. Bridge according to any one of the preceding claims, characterised in that the piers (11, 13) having a block-like configuration take the form of prefabricated units.

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