EP3795749B1

EP3795749B1 - Scaffold and method for supporting a bridge casting mould

Info

Publication number: EP3795749B1
Application number: EP20153082.1A
Authority: EP
Inventors: Anssi Koivumäki
Original assignee: Sepa Oy
Current assignee: Sepa Oy
Priority date: 2019-09-19
Filing date: 2020-01-22
Publication date: 2023-09-20
Anticipated expiration: 2040-01-22
Also published as: PL3795749T3; FI12557U1; ES2963660T3; EP3795749C0; EP3795749A1

Description

Background of the invention

The invention relates to a scaffold for supporting a casting mould for a cast-in-situ reinforced concrete bridge. This type of a scaffold is also referred to as bridge falsework. The scaffold is assembled for the time of bridge construction and dismantled after the bridge has been cast.
Further, the invention relates to a method for supporting a casting mould for a cast-in-situ reinforced concrete bridge.
The object of the invention is described in more detail in the preambles of independent claims of the application.
A bridge scaffold or falsework is a structure built for a temporary duration to support the structure of a bridge under construction. In other words, the bridge under construction is supported for the time of the construction work. Typically, the scaffold comprises scaffold foundations, a large number of vertical posts, diagonal and horizontal supports to prevent the vertical posts from buckling and tilting, and also top beams supported on the upper ends of the vertical posts, on which top beams the bridge casting mould is then built to be supported. The disadvantage of the currently used falsework is the requirement for a large amount of materials and construction work at the installation site. Documents DE1257818B and DE1101477B disclose some scaffold constructions.

Brief description of the invention

The idea of the invention is to provide a new and improved support scaffold for a bridge and a method for supporting a casting mould.
The features characterizing the scaffold according to the invention are presented in the characterizing part of the independent device claim.
The features characterizing the method according to the invention are presented in the characterizing part of the independent method claim.
The idea of the proposed configuration is that the scaffold is intended to support a casting mould for a cast-in-situ reinforced concrete bridge and it has been manufactured at least mainly from wood material and comprises vertical and horizontal supports. Further, the scaffold comprises several vertical support structures spaced from each other in the longitudinal direction of the bridge. Between these vertical support structures there are side by side several separate truss structures arranged along the longitudinal direction of the bridge. Said truss structures are wooden. Further, each truss structure is supported to the vertical structures only at support points located at the longitudinal ends of the truss structure, such that no separate vertical supports supported to the ground are arranged in the portions between the support points. In other words, the trusses are only supported by their ends.
The advantage of the proposed configuration is that building of the bridge scaffold may become quicker by using prefabricated truss structures. The truss structures may be manufactured under good factory conditions, whereby their quality will be good and their load bearing capacity guaranteed. Due to the truss construction, the bridge scaffold may comprise less timber than before, which lowers the cost of the scaffold. In addition, the scaffold as proposed is subject to a lower wind load because of the smaller surface area of the support structures.
The idea of one embodiment is that the upper beam of each of the truss structures is configured to constitute a support surface for the casting mould, such that no separate horizontal support beams are arranged in the scaffold.
According to the invention, said truss structure has a triangular structure comprising a horizontal upper beam and two diagonal downwardly oriented side beams providing the triangular shape. The triangular truss structure bears force particularly well, thus providing a structure which is strong in relation to its weight and also simple.
The idea of one embodiment is that at the support point between the truss structure and the vertical structure there is a pressure plate to distribute the vertical load over a larger surface area. The pressure plate may be, for example, a piece of plywood plate. Alternatively, the vertical load between the structures, i.e. the so-called stamp pressure, may be distributed over a larger surface area by means of nail plates.
According to the invention, the triangular truss structure is a roof truss turned upside down.
The idea of one embodiment is that truss structures of various sizes are manufactured for stock at the factory and are applied to bridge construction site scaffolds case-specifically. Already a few different trusses are sufficient to cover a majority of different types of scaffolds.
The idea of one embodiment is that the truss structure is made from normal strength graded sawn timber.
The idea of one embodiment is a method of building a support scaffold for the time of bridge construction using several truss structures supported between vertical structures.
The idea of one embodiment is that the proposed configuration is suited, in addition to the proposed application to new constructions, also to bridge renovation projects where a support scaffold for the structure is also necessary to be built adjacent to or in connection with an existing bridge.
The embodiments and their features as presented above may be combined to provide desired configurations.

Brief description of the figures

Some embodiments of the proposed configuration are presented in more detail in the following figures, in which

Fig. 1 schematically illustrates one prior art bridge scaffold as a side view,
Fig. 2 schematically illustrates one bridge scaffold according to the new configuration as a side view,
Fig. 3 schematically illustrates a detail of one scaffold comprising triangular truss structures between two casting towers,
Fig. 4 illustrates a schematical and cross-sectional detail of one scaffold not forming part of the present invention comprising substantially rectangular truss structures between two pillars or corresponding vertical structures, and
Fig. 5 is a simple diagram disclosing the features of the proposed configuration.

For clarity purposes, some embodiments of the proposed configurations are illustrated in the figures in a simplified form. The same elements and features are denoted by the same reference numerals in the figures.

Detailed description of some embodiments

Fig. 1 illustrates a prior art scaffold 1 comprising a large number of vertical posts 2, horizontal posts 3 and diagonal supports 4. The building of this type of a structure is laborious and slow.
Fig. 2 illustrates the new scaffold 1, wherein truss structures 6 are arranged between vertical support structures 5 to support an upper casting mould 7. The vertical support structures 5 may be casting towers 8 which are temporary structures. Under the vertical support structures 5 there are foundations 9, which may comprise compacted rock material and sills.
As seen from Fig. 3, the casting towers 8 may comprise vertical wood planks 10, horizontal wood planks 11, and diagonal supports 12. The truss structures 6 supported between the casting towers 8 comprise an upper beam 13 and diagonal downwardly oriented side beams 14. Between the beams 13 and 14 there are several diagonal and vertical intermediate beams to support the structure. The upper surface of the upper beam 13 functions as a support surface for the casting mould 7, and at the ends of the upper beam 13 there are support surfaces at which the truss structure 6 is supported on support surfaces of the casting towers 8. Between these support surfaces there may be members distributing the surface pressure over a larger surface area.
Fig. 4 illustrates a rectangular truss structure 6 supported between vertical support posts 15 which is not part of the present invention. The support posts 15 may be piles which may have been driven into ground 16, and they function as the vertical support structure 5. The truss structure 6 may comprise upper beams 13a, 13b and diagonal supports 17 between the beams. Between the upper ends of the support posts 15 and the truss structure 6 there are support points 18 which may be provided with pressure plates.
The features disclosed in the diagram of Fig. 5 have already been discussed above in this document.
The figures and their description are only intended to illustrate the idea of the invention. However, the scope of protection of the invention is defined in the claims.

Claims

A scaffold (1) for supporting a casting mould (7) for a cast-in-situ reinforced concrete bridge;
the scaffold (1) having been manufactured at least mainly from wood material and comprising vertical and horizontal supports;

and wherein

the scaffold (1) comprises several vertical support structures (5) spaced from each other in the longitudinal direction of the bridge;

between the vertical support structures (5) there are side by side several separate truss structures (6) arranged along the longitudinal direction of the bridge;

the truss structures (6) are wooden; and

each truss structure (6) is supported to the vertical support structures (5) only at support points (18) located at the longitudinal ends of the truss structure, such that no separate vertical supports supported to ground (16) are arranged in the portions between the support points (18) ;

characterized in that

each truss structure (6) has a triangular structure comprising a horizontal upper beam (13) and two diagonal downwardly oriented side beams (14) providing the triangular shape to form of a roof truss turned upside down.
The scaffold according to claim 1, characterized in
that an upper beam (13) of each of the truss structures (6) is configured to constitute a support surface for the casting mould (7), such that no separate horizontal support beams are arranged in the scaffold (1).
The scaffold according to claim 1 or 2, characterized in
that at the support point (18) between the truss structure (6) and the vertical support structure (5) there is a pressure plate configured to distribute the vertical load applied to the scaffold (1) over a larger surface area between the truss structure (6) and the vertical support structure (5).
A method for supporting a casting mould (7) for the time of bridge construction,
the method comprising supporting the casting mould (7) to ground (16) by means of a scaffold (1);

that the scaffold (1) is provided with several vertical support structures (5) spaced from each other in the longitudinal direction of the bridge;

the scaffold (1) is provided with several wooden truss structures (6);

several separate truss structures (6) are arranged between the vertical support structures (5) side by side;

the longitudinal ends of each of the truss structures (6) are supported to the vertical support structures (5); and

the portions between the vertical support structures (5) in the scaffold (1) are configured without separate vertical supports supported to the ground (16);

characterized by

using the scaffold (1) as claimed in any one of the previous claims 1 - 3.
The method according to claim 4, characterized in that
the vertical support structures (5) are also manufactured from wood material, such that the entire scaffold (1) is manufactured at least mainly from wood.
The method according to claim 4 or 5, characterized in that
the scaffold (1) is provided with a free passageway under the truss structure (6).