Method for erecting a bridge using at least one partially prefabricated bridge superstructure section

Abstract

The invention relates to a method for erecting a bridge, wherein at least one bridge superstructure section is at least partially prefabricated in a bridge-side location by positioning several longitudinal beams next to each other transversely to their longitudinal extension direction and connecting the longitudinal beams arranged next to each other in their respective end regions by crossbeams made in cast-in-place concrete, wherein the at least partially prefabricated bridge superstructure section is transported from the bridge-side location to the bridge site and moved onto a bridge substructure of the bridge.

Description

[0001] The present invention relates to a method for erecting a bridge, wherein at least one bridge superstructure section is at least partially prefabricated in the adjacent bridge layer. According to the invention, several longitudinal girders are positioned next to one another transversely to their longitudinal direction. The longitudinal girders thus arranged next to one another in the adjacent bridge layer are connected to one another at their respective end regions by cross girders cast in-situ. The bridge superstructure section prefabricated in this way is transported from the adjacent bridge layer to the bridge site and lowered into its final position onto a bridge substructure.

[0002] Such a method can reduce the construction time for such a bridge. This is particularly relevant when an existing bridge structure is to be replaced. A shorter construction time can reduce the disruption to the traffic route passing over the bridge. This is achieved, among other things, by allowing the construction of the bridge superstructure section in the adjacent bridge layer to be carried out in parallel with other work such as the demolition of an existing structure and / or the construction, replacement, or rehabilitation of the bridge substructure.

[0003] Furthermore, when used to replace a bridge structure that carries a lower traffic route passing beneath it, the method according to the invention can reduce the necessary closure times, particularly for the lower traffic route. This is particularly relevant when the method is used to replace motorway bridges, especially when replacing the bridges at a motorway interchange.

[0004] Preferably, the bridge superstructure section is supplemented with edge caps on the sides that laterally border a roadway leading over the bridge superstructure section. Particularly preferred are at least partially prefabricated edge caps.

[0005] Preferably, the method also comprises the prior setting up of a pre-assembly station adjacent to the bridge, on which the at least one bridge superstructure section is pre-assembled.

[0006] To construct the cross girders in cast-in-place concrete, a cross girder formwork is preferably constructed, cross girder reinforcement is inserted into the cross girder formwork, and the cross girder is then cast in cast-in-place concrete. After the cast-in-place cross girder has hardened, the formwork can be removed. This allows for the simple construction of cross girders that connect the adjacent longitudinal girders of the bridge superstructure section in such a way that the bridge superstructure section can be transported from the adjacent bridge level to the bridge and lowered onto the bridge substructure.

[0007] Preferably, cross-beam elements, particularly prefabricated components, are first positioned in the bridge's secondary layer. The longitudinal beams of a bridge superstructure section are then positioned next to each other with their respective ends on one of the cross-beam elements. The use of appropriate cross-beam elements, particularly prefabricated components, enables precise positioning of the longitudinal beams relative to each other, both in the longitudinal direction and transversely to it. This allows the bridge superstructure section to be easily manufactured so that it can be precisely inserted onto the bridge substructure.

[0008] Preferably, at least one of the cross-beam elements is designed as an end cross-beam element intended for positioning on a bridge abutment of the bridge substructure. Such a cross-beam element designed as an end cross-beam element is placed on a bridge abutment of the bridge substructure during retraction. Such an end cross-beam element forms a defined surface, particularly on its underside, via which the bridge superstructure section comes into contact with the abutment. This makes it easy to ensure that the bridge superstructure section is correctly aligned with the bridge abutment or the bridge bearings arranged on the bridge abutment during retraction. This makes the method particularly reliable.

[0009] Particularly preferably, the crossbeam is constructed in-situ as an end crossbeam encompassing the end crossbeam element at the end regions of the longitudinal beams of a bridge superstructure section located in the region of an end crossbeam element. The end crossbeam element thus becomes part of such an end crossbeam, which connects the longitudinal beams in the area where the bridge superstructure section is positioned on an abutment of the bridge substructure section. This simplifies the transport of the bridge superstructure section, including the end crossbeam element. The process becomes particularly reliable.

[0010] Preferably, temporary supports are initially constructed in the adjacent bridge layer in the areas where the bridge superstructure section will rest on the bridge substructure. By using such temporary supports, the conditions on the bridge structures to be erected, for example different heights of the support points of an abutment relative to a bridge pier or the other bridge abutment, can be easily reproduced in the adjacent bridge layer. This makes it easy to manufacture a bridge superstructure that can be precisely lowered onto the bridge substructure. Furthermore, this allows the bridge superstructure section to be constructed at a distance from the ground surface, which simplifies the transport of the bridge superstructure section to the bridge site. This makes the process particularly reliable.

[0011] Particularly preferably, the cross girders are positioned on the temporary supports. This is advantageous when the cross girders are the parts via which the bridge superstructure section is in contact with the bridge substructure. Furthermore, particularly preferably, at least one of the cross girder elements is brought into a position rotated relative to the horizontal, in particular by pressing, and fixed there. As a result, a bridge superstructure section for a bridge structure can be easily manufactured in the secondary layer, the roadway of which is inclined relative to the horizontal from one bridge abutment to the other bridge abutment and / or in which the roadway is inclined relative to the horizontal as viewed in the longitudinal direction of the bridge. In this way, the method can be used to easily and reliably realize different bridge structures, even with more complex geometries.

[0012] The method is preferably used to construct a multi-span bridge. A multi-span bridge is a bridge that spans at least two spans. Spans are the sections between an abutment and the bridge pier closest to the abutment, or between two bridge piers arranged adjacent to each other in the longitudinal direction of the bridge. In this method, bridge superstructure sections are at least partially prefabricated, each of which is intended to span a span of the multi-span bridge. The bridge superstructure sections thus extend between a bridge abutment and the bridge pier closest to the bridge abutment, or between two adjacent bridge piers. The prefabricated bridge superstructure sections are transported from the bridge abutment to the bridge site and lowered onto the bridge substructure.The individual bridge superstructure sections are not connected to each other in the adjacent bridge section, or are only detachably connected. The individual bridge superstructure sections can then be transported and retracted independently of each other from the adjacent bridge section to the bridge site. In this way, such a multi-span bridge can be constructed easily, quickly, and / or with reduced closure times for a road leading over the bridge structure and, in particular, for a lower traffic route possibly passing under the bridge structure.

[0013] Preferably, the longitudinal beams are positioned on cross-beam elements, with at least one of the two cross-beam elements on which the longitudinal beams of a bridge superstructure section are positioned being designed as a central cross-beam element. A central cross-beam element refers to a cross-beam element that is placed in the bridge's secondary layer in the area where the bridge substructure has a bridge pier. The use of such a central cross-beam element makes it possible to easily erect the bridge superstructure sections so that they are correctly aligned relative to the bridge pier when subsequently lowered onto the bridge substructure. The method can thus be implemented particularly simply.

[0014] Particularly preferably, the ends of the longitudinal girders of a bridge superstructure section, which are arranged on the central cross-girder element, are connected by a cross-girder arranged adjacent to the central cross-girder element and constructed in-situ as a stiffening cross-girder. The stiffening cross-girders are designed to connect the longitudinal girders of the bridge superstructure element to one another in such a way that the bridge superstructure section can be transported as a unit from the bridge secondary layer to the bridge site and retracted onto the bridge substructure. The stiffening cross-girder is constructed in-situ concrete adjacent to the central cross-girder element in such a way that the central cross-girder element is not connected to the stiffening cross-girder. The bridge superstructure section can therefore be moved independently of the central cross-girder element.This is particularly advantageous when the ends of two different bridge superstructure elements of a multi-span bridge are supported on the central crossbeam element. These can then be moved independently of the central crossbeam element and thus, in particular, independently of each other.

[0015] Preferably, two lifted bridge superstructure sections, which are arranged directly one behind the other on the bridge substructure in the longitudinal direction, are connected to each other via a central crossbeam cast in-situ. After the bridge superstructure sections have been lowered onto the bridge substructure, two bridge superstructure sections arranged directly adjacent in the longitudinal direction of the bridge structure can be monolithically connected via such a central crossbeam. This method thus allows a continuous bridge superstructure to be constructed in a simple manner. The use of at least partially prefabricated bridge superstructure sections enables the construction of such a multi-span bridge particularly quickly.Since a bridge superstructure section spanning more than one span would be statically overdetermined when lifted onto the bridge, very tight tolerances would have to be maintained or damage to such a bridge superstructure section spanning more than one span would be expected, particularly due to the load case of column settlement. The use of at least partially prefabricated bridge superstructure sections, each spanning one span and subsequently connected by central crossbeams cast in-situ, circumvents this problem.

[0016] To construct the central crossbeam in cast-in-place concrete, it is preferable to first construct a central crossbeam formwork. Subsequently, central crossbeam reinforcement is inserted into the area between the bridge superstructure elements arranged directly one behind the other in the longitudinal direction. The central crossbeam can then be constructed in cast-in-place concrete. If necessary, the central crossbeam formwork can then be removed.

[0017] Particularly preferred are the stiffening cross beams for formwork when casting the central cross beam in-situ. This reduces the effort required for formwork and demoulding of the central cross beam.

[0018] Preferably, the at least partially prefabricated bridge superstructure section is lifted from the central cross-girder element. The central cross-girder element is then placed onto a bridge pier of the bridge substructure. During the subsequent relocation onto the bridge substructure, the bridge superstructure section is placed back onto the same central cross-girder element on which it was at least partially prefabricated in the bridge substructure. For this purpose, the central cross-girder element is first moved from the bridge substructure to its final position above the central pier. The positioning of the bridge superstructure section on the bridge substructure can thus be reliably ensured in a particularly simple manner.

[0019] Particularly preferably, the central cross-beam element placed on the bridge pier is laterally supported. This can be achieved, in particular, by means of auxiliary yokes erected on both sides of the bridge pier or by means of a lowering wedge between the central cross-beam element and the central pier. The central cross-beam element can thus be securely positioned on the bridge pier, and a bridge superstructure section, as well as the bridge superstructure section immediately adjacent to this bridge superstructure section in the longitudinal direction, can be placed on the central cross-beam element. This method is particularly reliable.

[0020] Preferably, the longitudinal girders are provided with sheaths for tendons. In the retracted position of the bridge superstructure sections, the sheaths are arranged adjacent to the area in which a central cross girder is constructed in in-situ concrete, in particular emerging upwards from the longitudinal girder. Before the central cross girder is constructed in in-situ concrete, the sheaths are supplemented in such a way that they span one or more bridge piers. After the central cross girder is constructed in in-situ concrete, tendons are guided through the sheaths and at least the bridge superstructure sections arranged directly one behind the other in the longitudinal direction of the bridge structure are braced against one another via the tendons. For this purpose, the longitudinal girders orthe bridge superstructure sections are to be arranged transversely to the longitudinal direction and to be aligned relative to one another in the final position in such a way that the cladding tubes of two adjacent bridge superstructure sections are exactly opposite one another when viewed in the longitudinal direction.

[0021] By using appropriate ducts, the bridge superstructure sections, which are monolithically connected by the central crossbeams cast in-situ, can be prestressed via tendons that pass through the duct sections. This allows the bridge structure constructed using this method to be designed as a continuous girder bridge. Due to the static overdetermination of a continuous girder resting on the bridge abutments and at least one bridge pier, such a continuous girder bridge cannot be constructed using a single prefabricated bridge superstructure element, or only with very narrow tolerance limits, both during production and during installation. The risk of damage to such an overdetermined continuous girder, particularly due to the load case of column settlement, is very high.This problem is avoided by using individual prefabricated bridge superstructure sections, which are then joined to form a continuous girder using the central cross girders cast in-situ and the subsequently added prestressing elements. This method makes it easy to construct a multi-span bridge with continuous girders using prefabricated components. Compared to the alternative construction of a continuous girder bridge in situ at the bridge site, the construction time of the bridge structure and / or the closure periods for traffic routes affected by the construction of the bridge can be significantly reduced. For the replacement of a motorway junction using this method, construction time reductions from approximately 4.5 years to approximately 1.5–2 years are possible.

[0022] In a preferred embodiment, at least some of the ducts are provided in such a way that they extend continuously throughout the entire bridge structure in the longitudinal direction. Tendons for continuity prestressing can be guided through ducts designed and completed in this way.

[0023] Alternatively or additionally, at least some of the ducts are designed so that the tendons guided through these ducts extend over only one or two bridge piers. Preferably, the longitudinal girders of the bridge superstructure sections are provided with anchor blocks for appropriate prestressing. This allows the prestressing to be applied specifically in the area of ​​the bridge piers. The effort required to brace the bridge superstructure sections against each other is reduced.

[0024] After the tendons have been guided through the ducts and tensioned, the ducts can be grouted with cement.

[0025] Preferably, the partially prefabricated bridge superstructure sections are provided with connecting reinforcement or a shear and upper reinforcement layer for a deck slab in the adjacent layer. The deck slab is then reinforced in the bridge piers and completely concreted once the bridge superstructure sections have been retracted into their retracted position. By completing at least part of the reinforcement work for a deck slab in the adjacent bridge layer, the construction time can be further reduced.

[0026] Particularly preferred is a continuous deck slab cast in in-situ concrete after each prefabricated bridge superstructure section has been lifted into place. This method makes it possible to create a bridge structure with a continuous deck slab despite the use of prefabricated bridge superstructure elements.

[0027] In an alternative, preferred embodiment of the method, the bridge superstructure sections are partially provided with a roadway slab in the adjacent layer. After the bridge superstructure sections have been installed, these sections are completed by adding in-situ concrete to form a finished roadway slab. The roadway slab is initially left unfinished, particularly in the area where the central crossbeam is to be cast in-situ. When the central crossbeam is cast in-situ, the roadway slab can then be added simultaneously.

[0028] Preferably, at least two, and more preferably all, bridge superstructure sections are constructed in the secondary layer one behind the other in the longitudinal direction and precisely aligned with one another. The bridge superstructure sections should be constructed in the secondary layer in such a way that they are arranged and aligned as they will later lie on the bridge substructure in the retracted position. This makes it easy to arrange any connection points of the individual bridge superstructure sections in the correct alignment with one another when constructing the bridge superstructure sections for later connecting adjacent bridge superstructure sections. Such connection points can be, for example, the ducts for the tendons or reinforcing bars, which are arranged in particular in the stiffening cross girders in such a way that, after a bridge superstructure section has been retracted, they extend from one stiffening cross girder into the adjacent stiffening cross girder orcan be pushed into an opening located therein. This makes the process much easier. Otherwise, such connection points would have to be precisely measured. Furthermore, the subsequent connection of the bridge superstructure sections via these connection points can be tested in the adjacent bridge layer. Any defects can thus be identified and reworked in the adjacent bridge layer. This is significantly easier and more cost-effective than if defects were only discovered after the individual bridge superstructure sections have been driven onto the bridge substructure.

[0029] Further advantages and details of the invention can be found in the following description of the figures. They show: Fig. 1 the building site in the adjacent location with temporary supports; Fig. 2 cross-beam elements arranged on the temporary supports; Fig. 3 longitudinal cross members arranged on the cross member elements; Fig. 4 the construction of the cross beams in in-situ concrete; Fig. 5 - Fig. 8 the transport of the bridge superstructure sections from the construction site adjacent to the bridge to the location of the bridge and the insertion of the bridge superstructure sections onto a bridge substructure; Fig. 9 the addition of the reinforcement ducts and the construction of the central cross beam in in-situ concrete; Fig. 10 a cross section through a bridge superstructure section in a first embodiment; Fig. 11 a cross-section through a bridge superstructure section in a second embodiment with anchor blocks; Fig. 12 a cross-section through the bridge superstructure section according to Fig. 11 in the area of ​​the anchor blocks.

[0030] Parts with the same or similar functions are provided with identical reference numerals where appropriate. Individual technical features of the exemplary embodiments described below can be combined with the features of the independent claim as well as with the features of individual exemplary embodiments described above to form inventive objects.

[0031] Fig. Figure 1 shows a construction site for the construction of a bridge superstructure section 2 adjacent to a bridge 4 to be constructed using the method. In the exemplary embodiment, the bridge 4 is constructed as a multi-span bridge with two spans. Accordingly, two bridge superstructure sections 2 are at least partially prefabricated in the adjacent bridge section.

[0032] In Fig. 1 shows that temporary supports 6 are initially erected in the bridge's secondary layer. The position of these temporary supports 6 corresponds to the position of the abutments 10 and the bridge pier 12 of a bridge substructure 8 of the bridge 4. The bridge, designed as a multi-span bridge with two spans in the exemplary embodiment, can also be designed with more than two spans. Preferably, correspondingly more temporary supports 6 are then prepared in the bridge's secondary layer.

[0033] Cross beam elements 14 are positioned on the temporary supports 6. This state is shown in Fig. 2. These cross-beam elements 14 are particularly designed as prefabricated parts. In the illustrated embodiment, the cross-beam elements 14 on the left and right temporary supports 6 each represent an end cross-beam element 16. The cross-beam element 14 positioned on the centrally arranged temporary support 6 represents a central cross-beam element 18. To construct a multi-span bridge with more than two spans, additional central cross-beam elements 18 are provided on the additional temporary supports 6.

[0034] Longitudinal beams 20 are positioned on the cross beam elements 14. For each bridge superstructure section, several longitudinal beams 20 are positioned next to each other transversely to their longitudinal extension direction L. Two different embodiments of the longitudinal beams 20 arranged next to each other in this way are shown in the cross sections of the Fig. 10 to 12 shown.

[0035] In Fig. 3, the longitudinal girders 20 are arranged horizontally aligned both in the longitudinal direction L and transversely to their longitudinal direction L. If the bridge to be erected provides bridge superstructure sections that are rotated in one or two directions relative to this horizontal, the cross girder elements 14 can, if necessary, be brought into a correspondingly rotated position on the respective temporary supports 6. The cross girder elements 14 are then fixed in this position on the temporary support 6. This can, in particular, ensure that the underside of the cross girder elements 14 is aligned perpendicular to the direction of gravity when the bridge superstructure sections 2 are positioned on the bridge substructure 8, even if the longitudinal girders 20 on the bridge 4 are to be arranged deviating from the horizontal, for example because the bridge has a gradient.

[0036] In Fig. 3 shows that the longitudinal beams 20 have cladding tubes 22. In the exemplary embodiment, these cladding tubes 22 are arranged in anchor blocks 24 of the longitudinal beams 20.

[0037] Fig. 4 shows that the end regions of the longitudinal girders 20 are connected to one another by cross girders 26 cast in-situ concrete. The cross girders 26 on the leftmost temporary support 6 and on the rightmost temporary support 8 are designed as end cross girders 28. These are configured to rest on an abutment 10 of the bridge substructure 8. In the exemplary embodiment, the end cross girders 28 are constructed such that the end cross girder elements 16 each become part of the corresponding end cross girder 28. In the region of the central cross girder element 18, the cross girders 26 are constructed as stiffening cross girders 30. These stiffening cross girders 30 are formed and cast in-situ concrete such that the central cross girder element 18 is not connected to the stiffening cross girders 30.

[0038] Fig. Figure 4 also shows that reinforcement for a roadway slab is arranged on the longitudinal beams 20, and the roadway slab 34 can already be partially pre-concreted. The area above the central temporary support 6 with the central cross-beam element 18 and the stiffening cross-beams 30 remains unfinished.

[0039] Fig. 5 to Fig. 8 shows the transport of the bridge superstructure sections 2 from the construction site adjacent to the bridge to the location of bridge 4. Fig. 8 shows the insertion of the bridge superstructure sections 2 onto the bridge substructure 8, in particular the abutments 10 and the bridge pier 12. In Fig. 6 and Fig. 7 it can be seen that the central cross member element 18, unlike the end cross member elements 16, which became part of the end cross member 28 during the construction of the end cross member 28, is not transported together with the bridge superstructure sections 2.

[0040] As in Fig. As shown in Figure 8, the central cross-beam element 18 is placed on the bridge pier 12 before the bridge superstructure sections 2 are retracted. This procedure ensures that the bridge superstructure sections 2 can be easily positioned in the retracted position in the same way as they were constructed in the bridge secondary layer. The central cross-beam element 18 can be supported in the position on the bridge pier 12 by lateral auxiliary yokes (not shown). This facilitates the retraction of the bridge superstructure sections 2 onto the bridge substructure 8.

[0041] In the exemplary embodiment, the bridge superstructure sections are transported via self-propelled modular transporters (SPMTs). The bridge superstructure sections 2 are lifted via lifting devices mounted on these SPMTs. After the bridge superstructure sections 2 have been transported into the area of ​​the bridge substructure 8, they are lowered downwards via these lifting devices and thus retracted onto the bridge substructure 8.

[0042] After the bridge superstructure sections 2 have been retracted, the cladding tubes 22 are connected to each other in the area of ​​two adjacent bridge superstructure sections 2, as shown in Fig. 9. A central crossbeam 36 is then constructed using cast-in-place concrete. The central crossbeam 36 monolithically connects two adjacent bridge superstructure sections 2. In the exemplary embodiment, the gap between the two adjacent bridge superstructure sections 2 is filled with cast-in-place concrete.

[0043] The construction of the central crossbeam 36 in cast-in-place concrete may include the construction of a corresponding central crossbeam formwork and the introduction of central crossbeam reinforcement. Preferably, as shown in the exemplary embodiment, the respective stiffening crossbeams 30 of the bridge superstructure sections 2 are at least partially used for the formwork. This reduces the effort required for the formwork and, in particular, avoids demolding, with the associated disruption to the adjacent traffic area. The construction of the central crossbeam 36 is facilitated.

[0044] Particularly preferably, reinforcement bars are provided in the stiffening crossbeams 30 of at least one bridge superstructure section 2, which, after the bridge superstructure sections 2 have been moved into the retracted position, are displaced relative to the stiffening crossbeams 36 such that they are inserted into corresponding receptacles of the stiffening crossbeam 36 of the oppositely arranged bridge superstructure section 2. If such reinforcement bars are used, the illustrated construction of the bridge superstructure sections 2 in the secondary bridge layer one behind the other, as they are to be positioned in the bridge structure 4 to be erected, is particularly advantageous.

[0045] After the central cross member 36 has been constructed, tendons are guided through the ducts 22, and the bridge superstructure sections 2 are braced against each other via the tendons. As a result, a continuous girder bridge is constructed using the method shown in the exemplary embodiment. This is shown in Fig. 9 shown.

[0046] Fig. 10 shows a first cross section through a bridge superstructure section 2 with eight or more longitudinal beams 20 arranged next to one another in the longitudinal direction L. The bridge superstructure section 2 is provided with edge end caps 38.

[0047] Fig. 11 and Fig. 12 each show a section through a bridge superstructure section 2 according to the Fig. 1 to 9, in which the longitudinal beams 20 are provided with anchor blocks 24. Also visible are the ends of the cladding tubes 22 in the anchor blocks 24.

[0048] Instead of using anchor blocks 24, the sheathing tubes 22 can also be provided directly in the longitudinal girders. In particular, the sheathing tubes 22 arranged in the longitudinal girders 20 can be designed such that tendons extending across the entire bridge structure can be guided through them. This allows for continuity prestressing of the bridge.

Claims

[1] Method for erecting a bridge (4), wherein at least one bridge superstructure section (2) is at least partially prefabricated in a bridge adjacent location by positioning a plurality of longitudinal beams (20) next to one another transversely to their longitudinal extension direction (L) and connecting the longitudinal beams (20) arranged next to one another in their respective end regions by cross beams (26) produced in situ concrete, wherein the at least partially prefabricated bridge superstructure section (2) is transported from the bridge adjacent location to the location of the bridge (4) and moved onto a bridge substructure (8) of the bridge (4). [2] Method according to claim 1, characterized by that firstly cross-beam elements (14), in particular designed as prefabricated parts, are positioned in the bridge secondary layer and then the longitudinal beams (20) of the bridge superstructure section (2) are positioned next to one another with their ends on one of the cross-beam elements (14). [3] Method according to one of claims 2, characterized by that at least one of the cross-beam elements (14) is designed as an end cross-beam element (16) intended for positioning on a bridge abutment (10) of the bridge substructure (8). [4] Method according to claim 3, characterized in that the cross member (26) is constructed in-situ concrete as an end cross member (28) encompassing the end cross member element (16) at the end regions of the longitudinal members (20) arranged in the region of an end cross member element (16). [5] Method according to one of the preceding claims, characterized by that in the bridge annex, temporary supports (6) are initially constructed in the areas where the bridge superstructure section (2) rests on the bridge substructure (8). [6] Method according to 5 and one of claims 2 to 4, characterized by that the cross member elements (14) are positioned on the temporary supports (6). [7] Method according to claim 6, characterized by that at least one of the cross member elements (14) is brought into a position rotated relative to the horizontal and fixed there, in particular by pressing. [8] Method according to one of the preceding claims for erecting a bridge (4) designed to have at least two fields, wherein in the bridge secondary layer two or more bridge superstructure sections (2) each intended to span a field of the multi-field bridge are at least partially prefabricated, wherein the at least partially prefabricated bridge superstructure sections (2) are transported from the bridge secondary layer to the location of the bridge (4) and the respective bridge superstructure sections (2) are retracted onto the respective parts of the bridge substructure (8) of the multi-field bridge to span the respective field of the multi-field bridge. [9] Method according to claim 8 and one of claims 2 to 7, characterized bythat at least one of the two cross-beam elements (14) on which the longitudinal beams (20) of a bridge superstructure section (2) are positioned is designed as a central cross-beam element (18). [10] Method according to claim 9, characterized by that the ends of the longitudinal beams (20) of a bridge superstructure section (2) arranged on the central cross-beam element (18) are connected by a cross-beam (26) arranged adjacent to the central cross-beam element (18), which is constructed as a stiffening cross-beam (30) in in-situ concrete. [11] Method according to one of claims 8 to 10, characterized by that two raised bridge superstructure sections (2), which are arranged directly one behind the other on the bridge substructure (8) in the longitudinal direction (L), are connected via a central cross member (36) made of in-situ concrete. [12] Method according to claim 10 and 11, characterized bythat the stiffening cross beams (30) are used for formwork for concreting the central cross beam (36) in in-situ concrete. [13] Method according to one of claims 8 to 12, characterized by that the at least partially prefabricated bridge superstructure section (2) is lifted off the central cross-beam element (18), the central cross-beam element (18) is then moved onto a bridge pier (12) of the bridge substructure (8) and the bridge superstructure section (2) is placed back onto the central cross-beam element (18) when moved onto the bridge substructure (8). [14] Method according to claim 13, characterized by that the central cross member element (18) placed on the bridge pier (12) is supported laterally. [15] Method according to one of claims 11 to 14, characterized byin that the longitudinal girders (20) are provided with sheathing tubes (22) for tendons, which, in the retracted position of the bridge superstructure sections (2), protrude from the longitudinal girder (20) in particular upwards, adjacent to the area in which a central cross girder (36) is constructed in in-situ concrete, wherein the sheathing tubes (22) for tendons are supplemented so as to span one or more bridge piers (12) before the central cross girder (36) is constructed in in-situ concrete, wherein after the central cross girder (36) is constructed in in-situ concrete, tendons are guided through the sheathing tubes (22) and at least the bridge superstructure sections (2) arranged directly one behind the other in the direction of longitudinal extension (L) are braced against one another via the tendons. [16] Method according to claim 15, characterized by that at least some of the cladding tubes (22) are designed to be continuous in the longitudinal direction (L) through which tendons are guided for continuity prestressing. [17] Method according to claim 14 or 15, characterized by that at least some of the cladding tubes (22) are designed in such a way that tendons are guided through these cladding tubes (22) which extend only over one or two bridge piers (12). [18] Method according to one of claims 8 to 17, characterized by that the partially prefabricated bridge superstructure sections (12) are provided with a connecting reinforcement (32) for a roadway slab (34) in the bridge adjacent layer. [19] Method according to one of claims 8 to 18, characterized by that after the partially prefabricated bridge superstructure sections (2) have been lifted into place, a continuous roadway slab (34) is constructed in in-situ concrete. [20] Method according to one of claims 8 to 18, characterized by that the bridge superstructure sections (2) in the adjacent position are partially provided with a deck plate (34) which is supplemented in the retracted position. [21] Method according to one of claims 8 to 20, characterized by that at least two, preferably all, bridge superstructure sections (2) in the bridge secondary layer are constructed one behind the other in the longitudinal direction (L) and exactly aligned with each other.

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