GB2266740A

GB2266740A - Arch structure

Info

Publication number: GB2266740A
Application number: GB9206118A
Authority: GB
Inventors: Hugh Howatson
Original assignee: THORBURN Ltd
Current assignee: THORBURN Ltd
Priority date: 1992-03-18
Filing date: 1992-03-18
Publication date: 1993-11-10
Anticipated expiration: 2012-03-18
Also published as: GB9206118D0; GB2266740B

Abstract

A basic arch formation for use in civil engineering work is constructed by providing an articulated side-by-side array of block form voussoirs (2), then supporting or lifting the array so that articulation occurs between successive voussoirs to cause the array takes up an arch configuration, and finally placing and setting the arch (1) in the desired location. Control and locating means (7, 8) are provided between adjacent voussoirs (2) for control of the arched configuration when the array is raised. Further building and finishing operations can be carried out on the basic arch (1) when located to provide a complete civil engineering work. The abutting ends (2A, B) of the voussoirs can be of rounded form to facilitate formation of the arch configuration, and adjacent voussoirs can be prevented from relative lateral movement, for example by means of projections (3) and recesses (10) which interfit. <IMAGE>

Description

Arch Structure The present invention relates to arch structure for use in civil engineering constructions such as for example in bridge building.

Arch structures have been used extensively in civil engineering work, especially in arch bridges. By virtue of the arch configuration loading in the structure can be essentially of a compressive nature so making the arrangement manifestly suitable for supporting loads over clear spans. Traditionally civil engineering arch structures have included a base arch formed of block members known as voussoirs supporting an upper masonry formation. The voussoirs are normally of trapezoidal form to accommodate the curve of the arch. This prior art arch has been constructed by building cantilever formations inwards and oppositely from either side of the arch to meet at the centre of the arch. The building of arches in this way is relatively difficult and time consuming, and consequently expensive.

It is an object of the present invention to obviate or mitigate the above disadvantages of the prior art.

According to one aspect of the present invention a method of forming an arch structure comprises providing a series of bodies or voussoirs in side-by-side array, setting and supporting the voussoir series by setting and support means such that the series adopts a desired arch formation, and positioning the arch at a selected location. The setting and support means preferably are removed after the arch has been positioned at said location, and the arch structure can then serve as a base arch formation for subsequent building and finishing operations to provide a completed work.

Preferably the voussoir array is suspended from carrier means in the desired arch formation.

Alternatively the voussoir array can rest on carrier means so as to take up the desired arch form.

The present invention also provides apparatus for use in the above method, said apparatus comprising a series of members adapted to be arranged in side-by-side articulated array, such that relative rotational movement is permitted between the members for the formation of an arch by the array, the members thereby constituting voussoirs of the arch, means being provided precluding relative lateral movement between adjacent members. The ends of the members are preferably adapted to permit said rotational movements when the members are in abutting relationship.

According to another aspect of the present invention an assemblage for the formation of an arch structure in civil engineering work comprises an articulated array of side-by-side voussoirs, locating means precluding relative lateral movement between voussoirs, and control means for controlling the relative angular position of adjacent voussoirs to enable the articulated voussoir array to adopt an arch form of desired geometric configuration. Preferably the control means comprise bracing means mounted on selected voussoirs and including projecting portions projecting over voussoirs adjacent the selected voussoir, and locking units located between said adjacent voussoirs and said projecting portions. The locking units can be adjustable to permit the array to adopt a substantially planar configuration and also to control and stabilise the arch form produced by the array.

The ends of the voussoirs are preferably adapted to facilitate rotational movement. for example, by being of rounded form, when the voussoirs are in abutting relationship, and the top surface of the voussoir can include recess portions whereby troughs are formed by adjacent voussoirs of the assembled array. These troughs can be filled with material, e.g. concrete, to facilitate keying of the voussoirs when the arch structure is located at site: the voussoirs can be of concrete material with or without reinforcement. When the arch structure is anchored at site, it will be possible to remove the control means.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Fig. 1 - shows a side view of a voussoir array of an arch, in an initial flat position in accordance with the present invention; Fig. 2 - shows a plan view of the array of Fig. 1; Fig. 3 - shows a pictorial view of a single voussoir of the array of Figs. 1 and 2; Fig. 4 - shows the section A-A of Fig. 3; Fig. 5 - shows a side view of the arch in the erected condition.

Fig. 6 - shows the arch carried by carrier means prior to location at a site; and Fig. 7 - shows a similar view to Fig. 6 but with the arch located and anchored at site with the voussoir control means removed, an alternative carrier also being indicated.

Referring to the drawings, an arch for use in civil engineering work, such as a bridge, comprises a side-byside array 1 of individual block members 2 which constitute voussoirs of the arch. The voussoirs 2, which can be moulded from concrete, are positioned in abutting relationship in the array 1 and to facilitate rotation between adjacent voussoirs 2 the ends 2A, 2B of the voussoirs are curved for male/female interfitting between voussoirs as can be seen in Fig. 1. Further to preclude relative lateral movement between voussoirs in the array 1, the voussoir 2 includes projections 3 locating in a recess 4 of the adjacent voussoirs.

The array 1 of articulated nature is erected into the arch form by a suitable means, and one such means comprise the carrier 4 shown in Fig. 6. Thus initially the carrier 4 is coupled to the voussoir array 1 by means of the cables 5 or other tie members having different selected lengths, when the array 1 lies flat as shown in Fig. 1. As the carrier 4 is raised the tie cables 5 straighten and tauten so resulting in the array l adopting--the arch form shown in Fig. 6. Additionally, control means are provided on the array 1 to stabilise the array in the arched condition and also to ensure the correct geometry of the arch.In this example, these control means comprise a pair of bracing beams 6, 7 attached temporarily to each voussoir 2 and having projecting portions 6A, 7A, extending over adjacent voussoirs in the array 1, and locking units 8 carried by the portions 6A, 7A, so as to be positioned between the portions and the underlying voussoirs. The locking units 8 have the facility to permit the array 1 to adopt the flat configuration shown in Fig 1 (desirable for initial assembly of the array on the ground) and to adjust so as to lock into place at a predetermined setting as the array 1 arches to define the geometry of the arch ring once the voussoirs are raised into position by the carrier 4. In particular the locking units 8 serve to limit the rotational movement between adjacent voussoirs, and these units 8 for example can take the form of movable spring urged members or levers.

Thus, the member or lever can occupy a contracted position when the array 1 is flat as in Fig. 1 and move automatically to an extended position when the array arches as in Fig. 5. The beams 6, 7 are arranged in a staggered fashion to facilitate installation. In the array of Figs. 1 and 2 the voussoirs 2 do not require to be physically joined as they are held together, during movement by the carrier 4, by virtue of gravity action and by the force applied by cables 5. It is preferred that the rounded face 2A is uppermost in the arch and this can be achieved by reversing the voussoirs as appropriate and providing a unique middle voussoir 2M.

When the arch is positioned in the anchoring points 9 at site, the control means (7,8) can be removed as shown in Fig. 7. Each voussoir 2 includes a recess 10 which aligns with the recess 4 of an adjacent voussoir to define a trough 11 in the array 1, and the trough 11 can be filled with concrete to provide keying between adjacent voussoirs. After the arch 1 is installed as shown in Fig. 7 further work and finishing operations can be carried out, such as shown by formations 12, to provide the completed work.

Fig. 7 shows an alternative arch carrying means 13 which comprises a temporary support structure on which the arch rests via voussoir supporting heads 14. When the arch is installed the carrying means 13 can be dropped (as shown) by virtue for example of an installed packing system to enable the means 13 to be removed.

The present invention constituted by the combination of uniquely shaped voussoirs and temporary control means (comprised by braces 6, 7 and locking units 8) provide a relatively simple and efficient means of erecting arches for the construction of arch bridges and other arch structures. In particular, the specially shaped voussoirs conveniently allow articulation between units during erection, alignment of units, continuity between units when erected, and load carrying capability once erected.

The concrete voussoirs can include reinforcements if desired, and instead of the voussoirs abutting freely at the faces 2A, 2B the voussoirs could be hinged together by suitable means. Also, two or more arches comprised by arrays 1 could be installed side-by-side to give greater width.

Claims

1. A method of forming an arch structure comprising providing a series of bodies or voussoirs in side-by-side array, setting and supporting the voussoir series by setting and support means such that the series adopts a desired arch formation, and positioning the arch at a selected location.

2. A method as claimed in claim 1, wherein the setting and support means are removed after the arch has been positioned at said location.

3. A method as claimed in claim 3, wherein further building and finishing operations are carried out on the arch.

4. A method as claimed in any one of the preceding claims wherein the voussoir array is suspended from carrier means in the desired arch formation.

5. A method as claimed in claim 4, wherein the array is carried by a beam via tie members between the beam and the array, said tie members being of varying length to provide the arch configuration.

6. A method as claimed in any one of claims 1 to 3, wherein the voussoir array rests on carrier means so as to take up the desired arch form.

7. A method as claimed in any one of the preceding claims, wherein the relative pivoting movement between successive voussoirs of the array is limited.

8. A method of forming an arch structure as claimed in claim 1 and substantially as hereinbefore described.

9. Apparatus for use in the method of any one of the preceding claims, said apparatus comprising a series of members adapted to be arranged in side-by-side articulated array, such that relative rotational movement is permitted between the members for the formation of an arch by the array, the members thereby constituting voussoirs of the arch, means being provided precluding relative lateral movement between adjacent members.

10. Apparatus as claimed in claim 9, wherein the ends of the members are adapted to permit said rotational movement when the members are in abutting relationship.

11. Apparatus as claimed in claim 10, wherein said ends are of arcuate form for mating of adjoining ends of members of the array.

12. Apparatus as claimed in any one of claims 9 to 11, wherein the means to preclude relative lateral movement between adjacent members comprises projections on members which fit into recesses in adjoining members.

13. An assemblage for the formation of an arch structure in civil engineering work comprises an articulated array of side-by-side voussoirs, locating means precluding relative lateral movement between voussoirs, and control means for controlling the relative angular position of adjacent voussoirs to enable the articulated voussoir array to adopt an arch form of desired geometric configuration.

14. An assemblage as claimed in claim 13, wherein the control means comprise bracing means mounted on selected voussoirs and including projecting portions projecting over voissoirs adjacent the selected voussoir, and locking units located between said adjacent voussoirs and said projecting portions.

15. An assemblage as claimed in claim 14, wherein the locking units are adjustable to permit the array to adopt a substantially planar configuration and also to control and stabilise the arch form produced by the array.

16. An assemblage as claimed in any one of claims 13 to 15, wherein the ends of the voussoirs are adapted to facilitate rotational movement, for example, by being of rounded form, when the voussoirs are in abutting relationship.

17. An assemblage as claimed in any one of claims 13 to 16, wherein the top surface of the voussoir includes recess portions whereby troughs are formed by adjacent voussoirs of the assembled array.

18. An assemblage as claimed in any one of claims 13 to 17, wherein said locating means comprise projection means interfitting in recess means.

19. Apparatus as claimed in any one of claims 9 to 17, wherein members or voussoirs are of concrete material with or without reinforcement.

20. Apparatus for the formation of an arch structure substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows 1. A method of forming an arch structure comprising providing a series of bodies or voussoirs in articulated side-by-side array, setting and supporting the articulated voussoir series by setting and support means so that articulation occurs between successive voussoirs to cause the series to adopt a desired arch formation, and positioning the arch at a selected location.