Prefabricated unit for refurbishment or construction of platforms

Abstract

A prefabricated platform unit (1), for construction or refurbishment of a railway station platform, has a stepped upper surface (4) with a recessed planar forward portion (4a) on which edge copers (23) are to be mounted. Refurbishment of an exiting platform may be performed by excavating a region (22) of the platform surface to the front edge, installing a prefabricated platform unit (1) in the excavated region, and installing edge copers (23). Construction of a new platform may include the steps of constructing foundations alongside the railway, constructing upstanding supporting members on the foundations, and mounting a superstructure including the prefabricated platform units on the supporting members.

Description

[0001] This invention relates to the construction of platforms for railway stations.

[0002] The increasing demand for rail travel is requiring train operating companies to create extra capacity by the use of longer trains, but many existing station platforms are too short to accommodate such trains. The construction of platform extensions is restricted by the requirement to minimise disruption to normal use of the existing platform, to accommodate the works within existing train service patterns, and to have possession of the track while much of the construction work is carried out.

[0003] Many existing platforms were constructed in the nineteenth or early twentieth century and do not comply with modern standards, in particular with regard to track clearance, i.e. the distance between the platform edge and the adjacent rail, which determines the gap across which a passenger has to step. When an existing platform is refurbished, it has to be brought up to standard.

[0004] It would therefore be desirable to be able to minimise the time for which track possession is required when constructing or refurbishing a railway station platform. In particular it would be desirable to be able to provide a structure which can be constructed quickly, without using time-consuming processes during possession.

[0005] In one aspect the present invention provides a prefabricated platform unit for construction or refurbishment of a railway station platform, the unit having a stepped upper surface, front and rear edge surfaces, and side edge surfaces, the upper surface comprising a forward portion, on which edge copers are to be mounted, and a rearward portion, with a step rising between the forward and rearward portions, the forward portion being planar.

[0006] In another aspect the invention provides a method of refurbishing a railway station platform, including the steps of excavating a region of the surface of the platform, the said region extending to the front edge of the platform, installing a prefabricated platform unit in the excavated region, and installing edge copers on the installed unit.

[0007] In another aspect the invention provides a railway station platform structure comprising: foundations alongside the railway; upstanding supporting members rising from the foundations; cross beams mounted on the supporting members and having cantilevered portions extending beyond the supporting members towards the railway; longitudinal beams on the cross beams, each longitudinal beam extending between a pair of the cross beams, there being at least two longitudinal beams between each pair of cross beams, at least one of these longitudinal beams being on the cantilevered portions of the cross beams and at least one of these longitudinal beams being remote from the cantilevered portions; and platform units on the longitudinal beams, the platform units having side edge surfaces extending away from the railway and having front edge surfaces extending along the railway beyond the ends of the cantilevered portions of the cross beams.

[0008] In another aspect the invention provides a method of constructing a railway station platform structure, including the steps of:

[0009] (a) constructing foundations alongside the railway;

[0010] (b) constructing upstanding supporting members on the foundations; and

[0011] (c) mounting on the supporting members a prefabricated superstructure comprising cross beams mounted on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway, longitudinal beams on the cross beams, and platform units on the longitudinal beams, side edge surfaces of the units extending away from the railway and front edge surfaces of the units extending along the railway beyond the ends of the cantilevered portions of the cross beams.

[0012] In another aspect the invention provides a method of constructing a railway station platform structure, including the following steps:

[0013] (a) constructing foundations alongside the railway;

[0014] (b) constructing upstanding supporting members on the foundations;

[0015] (c) mounting cross beams on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway;

[0016] (d) mounting longitudinal beams on the cross beams; and

[0017] (e) mounting platform units on the longitudinal beams so that side edge surfaces of the units extend away from the railway and front edge surfaces of the units extend along the railway beyond the ends of the cantilevered portions of the cross beams.

[0018] The invention will be described further, by way of example only, with reference to the accompanying drawings, in which:

[0019] FIG. 1 is a plan view of a prefabricated platform unit or slab unit primarily for refurbishment of an existing platform;

[0020] FIG. 2 is a side elevation of the slab unit;

[0021] FIG. 3 is an enlarged fragmentary vertical section taken on line III-III in FIG. 1;

[0022] FIG. 4 is an enlarged fragmentary vertical section taken on line IV-IV in FIG. 1;

[0023] FIG. 5 is an exploded isometric view of an existing platform and a refurbished part of the platform;

[0024] FIG. 6 is an isometric view of three slab units, showing a preferred embodiment for use in the construction of a new platform structure;

[0025] FIG. 7 is a vertical section through a platform structure incorporating the slab units of FIG. 6, in a first embodiment;

[0026] FIG. 8 is an exploded isometric view of the first embodiment of the platform structure;

[0027] FIG. 9 is a vertical section through a second embodiment of the platform structure; and

[0028] FIG. 10 is an exploded isometric view of the second embodiment of the platform structure.

[0029] A prefabricated slab unit 1, primarily for use in the refurbishment of an existing platform, is shown in FIGS. 1 to 4; it is a pre-cast concrete unit incorporating a reinforcing mesh 2. The slab unit 1 has a planar bottom surface 3 and a stepped upper surface 4. The slab unit has a nominal width of 2 metres (for example) and has a rectangular outline when viewed from above (FIG. 1). In the particular example shown, the outline is square. In general, the length of the slab unit from its front edge to its rear edge is at least equal to its width. Exemplary dimensions, in millimetres, are indicated in FIGS. 1 to 4. The slab unit has a front edge surface 6, a rear edge surface 7, and side edge surfaces 8,9, all of which are vertical surfaces. The upper surface 4 has a forward portion 4a which is planar and parallel to the bottom surface 3, a rearward portion 4b which is planar and slopes downwardly and rearwardly from its front edge to its rear edge, and a step 4c which rises vertically between the forward and rearward portions 4a,4b. The step 4c extends across the width of the slab unit, parallel to its front edge surface 6. In the forward portion there are several through-holes 11 (one hole may be sufficient) for supplying grout to the underside of the slab unit. The bottom surface 3 has a series of parallel grooves 12 for selectively receiving a neoprene rubber sealing strip 13 near the front edge surface 6. The side edge surfaces 8,9 have grooves 10 along the length of the rearward portion 4b, for receiving a neoprene rubber sealing strip (not shown).

[0030] The refurbishment of an existing platform will now be described with reference to FIG. 5. The existing platform comprises a front wall 14 of brickwork with back filling supporting paving 16 (which may comprise pre-cast slabs, bricks, or a layer of concrete, asphalt, or coated macadam), with coping stones 17 projecting beyond the front wall 14.

[0031] As a preliminary step, the platform surfacing is cut to a depth of 200 mm along a line 18 parallel to and spaced 2 metres from the front edge of the platform and along lines 19 which are spaced 2 metres apart and extending from the front edge of the platform to the line 18. In this way a series of existing platform squares are defined. The following process is then carried out.

[0032] (1) One existing platform square is excavated to a depth of 200 mm, without damaging the adjacent cut edges.

[0033] (2) Levelling elements in the form of shims or pads 21 are levelled on the excavated region 22 and fixed.

[0034] (3) A slab unit 1, carried by a crane, is installed on the pads 21, the sealing strip 13 being seated on the top of the front wall 14. The groove 12 selected to receive the sealing strip 13 will depend on the relationship between the position of the wall 14 and the required position of copers to be laid to define the platform edge.

[0035] (4) Grout is fed to the underside of the slab unit 1, using the holes 11. A preferred procedure is to inject the grout through the two holes which are remote from the front edge surface 6 until grout enters the two holes which are near the front edge surface 6. The sealing strip 13 prevents escape of grout from under the front edge surface of the slab unit, thereby preventing staining of the front wall 14.

[0036] (5) Lightweight edge copers 23 are installed on quick-setting epoxy adhesive mortar on the forward portion 4a. In the present example five edge copers 23 are mounted side by side across the two metre width of the slab unit. Depending on the size of the edge copers, more or fewer may be used, although there are preferably at least four. Accordingly, the copers 23 are small enough to be handled without undue strain, preferably weighing at most 25 kg if they are made of pre-cast concrete and being substantially lighter if they are made of less dense materials, for example plastics material. The edge copers 23 overlap the front edge of the slab unit 1 and are laid level so that their front edges are at a given horizontal and vertical spacing from the adjacent rail 24.

[0037] (6) Tactile paving elements 26 (which can be felt by a person's foot) are installed on quick-setting epoxy adhesive mortar, between the copers 23 and the step 4c, in such a manner as to compensate for any difference in level between the rear edges of the copers 23 and the front edge of the rearward portion 4b of the upper surface of the slab unit.

[0038] The above described steps (1)-(6) are repeated until at least part of the length of the existing platform has been refurbished.

[0039] The above described process has to take place during track possession. However, because of the use of the pre-formed slab units 1, the work can be carried out quickly, keeping track possession time to a minimum.

[0040] FIG. 6 shows platform units or slab units 1 which are longer from front to back than the slab units of FIGS. 1 to 5 and which can be used in the construction of a new platform structure, which may be an extension to an existing platform structure. In this case, the rearward portion 4b of the upper surface 4 is of greater length, has a more gradual slope (1 in 50) from front to back, and has a raised plinth 27 near the rear edge surface 7 of the slab unit 1. A drainage outlet 28 is provided in the front surface of the plinth 27. The forward portion 4a of the upper surface has the same dimensions as in FIGS. 1 to 5, but there are no grout holes. There is also no groove 12 in the underside of the slab unit. One side edge surface 9 has a key formation 29 for fitting in a recess or groove 31 in the opposite side edge surface 8 of an adjacent slab unit so as to prevent relative vertical movement of the adjacent slab units. The bottom surface of the slab unit 1 has integrally cast projections 32 for a purpose to be explained below. One slab unit 1 has a recess 33 in one edge, for receiving a lighting column (not shown).

[0041] A first embodiment of a platform structure incorporating the slab units 1 shown in FIG. 6 will now be described with reference to FIGS. 7 and 8, by describing the steps involved in its method of construction.

[0042] (1) Simple temporary mesh fencing 34 is set up at a spacing of 2 metres from the centre line of the outermost track rail 24 to define a border between the so-called red zone (in which it would be hazardous and, in some situations, not permitted to work when not in track possession) and the so-called green zone (in which it is safe to work under certain conditions, whether or not in track possession).

[0043] (2) In the green zone the ground is prepared and excavated to provide two trenches parallel to the track. Concrete is then poured into the trenches to form strip foundations 36.

[0044] (3) In situ concrete support columns 37 are constructed on the strip foundations 36 and incorporate vertically projecting corrosion resistant threaded tie bars of 16 mm diameter (not shown in FIG. 8).

[0045] (4) Pre-cast concrete cross beams 38 are craned in and positioned on the support columns 37. Each cross beam 38 is supported by two columns 37 and has a cantilevered portion 38a extending beyond the support columns 37 towards the track. Each cross beam 38 has two vertical through holes 39, which are formed during the casting of the concrete cross beam and which have a minimum diameter of 50 mm. These oversize holes 39 receive the threaded bars projecting upwards from the columns 37 and are used to locate the cross beams 38 relative to the support columns 37, nuts being threaded on the tie bars to provide a mechanical connection between the cross beam 38 and the support columns 37. Resilient rubber pads (not shown) with pre-formed holes to receive the threaded bars are located on top of the columns 37. The cross beams 38 incorporate holding down bolts (not shown) for connecting the base of the lighting column and one or more ducts 41 for the passage of electrical cables.

[0046] (5) Pre-cast longitudinal beams 42 are craned in and mounted on the cross beams 38. The upper edges of the cross beams 38 have recesses 43 which accommodate end portions 42a of the beams 42 resting on resilient rubber pads 44 at the bottoms of the recesses 43. Abutment surfaces 42b (recessed beneath the end portions 42a) face the respective side surfaces of the cross beams 38. The upper surfaces of the cross beams 38 are flush with the upper surfaces of the longitudinal beams 42.

[0047] (6) The slab units 1 are craned in and mounted on the supporting structure constituted by the cross beams 38 and longitudinal beams 42. The downward projections 32 on the slab units abut against respective side surfaces of two of the longitudinal beams 42 to locate the slab units in the direction towards and away from the track. The slab units 1 are installed one by one, engaging the key formation 29 on each slab unit with the corresponding groove 31 of the next slab unit. The joints between adjacent units are sealed by a dry rubber O-ring which, when compressed, forms a watertight seal. To assist installation, temporary lifting rings (not shown) can be fitted to anchorages (not shown) located in or near the plinth 27 and in the forward portion 4a of the upper surface of the slab unit.

[0048] (7) Platform fencing (not shown) is erected on the plinths 27 and electrical cabling is installed using the cable ducts 41 and cable support trays 46 mounted in facing longitudinal recesses 47 in a pair of the longitudinal beams 42.

[0049] (8) Platform lighting is installed, a lighting column being inserted through the recess 33 in at least one of the slab units 1 and bolted to the cross beam 38 below.

[0050] (9) Lightweight copers 23 and tactile paving elements 26 are then installed on the forward portions 4a of the upper surfaces 4 of the slab units 1 (in the manner described above with reference to FIG. 5).

[0051] (10) Anti-debris netting (not shown) is installed beneath the platform, by means of stainless steel eyes received in sockets (not shown) cast in the cross beams 38.

[0052] (11) Finally the temporary fencing 34 is removed.

[0053] It will be appreciated that steps (2), (3), (7), and (10) do not require track possession. The design of the platform structure ensures that the other steps, which will normally require track possession, can be carried out quickly and in separate stages.

[0054] A second embodiment of the platform structure will now be described with reference to FIGS. 9 and 10. The second embodiment differs from the first embodiment only in using piles instead of strip foundations. Accordingly, the above description, except for step (2), is applicable to the second embodiment and will not be repeated.

[0055] In the construction of the second embodiment, step (2) is replaced by the step of preparing the ground and inserting piles 36a into the ground at the intended locations of the supporting columns 37, which are subsequently constructed on the piles.

[0056] Various modifications may be made within the scope of the invention. In particular, the lengths of the cross beams 38 and the number of longitudinal beams 42 between each pair of cross beams may be varied to suit different platform widths (front to back). For a platform width of less than 3 metres (for example 2.5 metres) two longitudinal beams 42 may be sufficient. For platform widths of 3 or 3.5 metres, three longitudinal beams 42 may be sufficient. For a platform width of 4 metres, four longitudinal beams should be used. The position of the front longitudinal beam in relation to the front end of the cross beam will be the same in each case, so that pre-cast concrete manufacture of the cross beams can to some extent be standardised.

[0057] To accommodate curved track alignments the side edges of one or more of the slab units may be non-parallel, either converging or diverging away from the front edge, one or both of the side edges not being perpendicular to the front edge.

[0058] Cable-tray receiving grooves 47 may be provided in more than two of the longitudinal beams 42, and additional holes 41 may be provided in the cross beams 38 if one or more additional cable trays are fitted using these grooves.

[0059] To simplify construction of the superstructure on the support columns 37, the platform units 1 may be combined with the longitudinal beams 42 as prefabricated units, or longitudinal and cross beams may be combined as prefabricated units, or platform units and longitudinal and cross beams may be combined as prefabricated units. In each case the spacing of the supporting columns 37 would be reduced by approximately one half, the width of the prefabricated units being correspondingly reduced in order to keep the weight to be lifted within practicable limits.

[0060] Instead of fitting the edge copers and tactile paving elements on the slab units after the installation of the slab units, it may be possible to fit them on the slab units before the slab units are mounted on the supporting structure. It may also be possible to combine the tactile paving elements with the edge copers, or to omit the tactile paving elements.

[0061] The platform structure can be provided at any trackside location where it may be desired to bring a train to a halt in order to allow passengers or train operating staff to board or alight from the train or to attend to the maintenance of the exterior of the train.

Claims

1. A prefabricated platform unit for construction or refurbishment of a railway station platform, the unit having a stepped upper surface, front and rear edge surfaces, and side edge surfaces, the upper surface comprising a forward portion, on which edge copers are to be mounted, and a rearward portion, with a step rising between the forward and rearward portions, the forward portion being planar.

2. A unit as claimed in claim 1, in which the rearward portion of the upper surface slopes downwardly and rearwardly from adjacent the step.

3. A unit as claimed in claim 1 or 2, in which the rearward portion of the upper surface has a raised plinth adjacent the rear edge surface.

4. A unit as claimed in any preceding claim, in which one of the side edge surfaces has a key formation for fitting in a recess in a side edge surface of an adjacent unit.

5. A unit as claimed in any preceding claim, in which one of the side edge surfaces has a recess for receiving a key formation on a side edge surface of an adjacent unit.

6. A unit as claimed in any preceding claim, in which the unit is made of reinforced concrete.

7. A unit as claimed in any preceding claim, in which the length of the unit from front to rear is at least as great as its width.

8. A unit as claimed in any preceding claim, in which the unit is about 2 metres wide.

9. A unit as claimed in any preceding claim, in which the length of the forward portion of the upper surface from the front edge surface to the step is at least 1 metre.

10. A unit as claimed in any preceding claim, the unit being in the form of a slab having a substantially planar bottom surface, the forward portion of the upper surface being substantially parallel to the bottom surface.

11. A unit as claimed in claim 10, in which the unit has at least one through-hole communicating between the forward portion of the upper surface and the bottom surface, for supplying grout to the underside of the unit.

12. A unit as claimed in claim 11, in which the bottom surface has a groove for receiving a seal adjacent the front edge surface.

13. A unit as claimed in any of claims 10 to 12, in which the bottom surface has projections for locating the unit relative to a supporting structure.

14. A method of refurbishing a railway station platform, including the following steps:

(a) excavating a region of the surface of the platform, the said region extending to the front edge of the platform;

(b) installing in the excavated region a prefabricated platform unit according to any of claims 1 to 13; and

(c) installing edge copers on the forward portion of the upper surface of the installed unit.

15. A method as claimed in claim 14, in which, between steps (a) and (b), levelling elements are arranged in the excavated region to support the unit.

16. A method as claimed in claim 14 or 15, in which, between steps (b) and (c), grout is supplied to the underside of the unit.

17. A method as claimed in claim 16, in which the grout is supplied through at least one hole in the forward portion of the upper surface of the unit.

18. A method as claimed in claim 17, in which escape of grout from under the front edge of the unit is substantially prevented by a seal between the unit and the excavated region.

19. A method as claimed in any of claims 14 to 18, in which at least four edge copers are mounted side by side across the width of the unit.

20. A method as claimed in any of claims 14 to 19, in which the width of each edge coper is less than its length.

21. A method as claimed in any of claims 14 to 20, in which each edge coper weighs at most 25 kg.

22. A method as claimed in any of claims 14 to 21, in which the edge copers are installed on a quick-setting resin-based mortar.

23. A method as claimed in any of claims 14 to 22, in which, after step (c), paving elements are installed between the edge copers and the step in the upper surface of the unit.

24. A method as claimed in any of claims 13 to 22, in which, before step (a), the platform is cut to a given depth along lines delimiting a rear edge and side edges of the region to be excavated.

25. A railway station platform structure comprising a plurality of platform units according to any of claims 1 to 13 arranged side by side.

26. A platform structure as claimed in claim 25, in which the units carry edge copers mounted side by side on the forward portions of the upper surfaces of the units, the front edges of the copers being at a given horizontal spacing from the adjacent rail.

27. A platform structure as claimed in claim 26, including paving elements between the edge copers and the steps in the upper surfaces of the units.

28. A platform structure as claimed in claim 27, in which the paving elements have tactile upper surfaces.

29. A railway station platform structure comprising:

foundations alongside the railway;

upstanding supporting members rising from the foundations;

cross beams mounted on the supporting members and having cantilevered portions extending beyond the supporting members towards the railway;

longitudinal beams on the cross beams, each longitudinal beam extending between a pair of the cross beams, there being at least two longitudinal beams between each pair of cross beams, at least one of these longitudinal beams being on the cantilevered portions of the cross beams and at least one of these longitudinal beams being remote from the cantilevered portions; and

platform units according to claim 1 on the longitudinal beams, the side edge surfaces of the platform units extending away from the railway and the front edge surfaces extending along the railway beyond the ends of the cantilevered portions of the cross beams.

30. A platform structure as claimed in claim 29, in which the supporting members comprise columns.

31. A platform structure as claimed in claim 29 or 30, in which each cross beam is supported by two said supporting members.

32. A platform structure as claimed in any of claims 29 to 31, in which the supporting members and the cross beams have complementary formations which interengage to locate the cross beams relative to the supporting members.

33. A platform structure as claimed in claim 32, in which the said formations on the supporting members comprise tie bars and the said formations on the cross beams comprise through-holes.

34. A platform structure as claimed in any of claims 29 to 33, in which the cross beam are connected to the supporting members solely by mechanical connection devices.

35. A platform structure as claimed in any of claims 29 to 34, in which the cross beams have upwardly and laterally open recesses which accommodate end portions of the longitudinal beams.

36. A platform structure as claimed in claim 35, in which resilient pads are interposed between the said end portions and the bottoms of the said recesses.

37. A platform structure as claimed in claim 35 or 36, in which the longitudinal beams have end abutment surfaces recessed beneath the said end portions.

38. A platform substructure as claimed in any of claims 29 to 34, in which the cross beams are integral with the longitudinal beams.

39. A platform structure as claimed in any of claims 29 to 38, in which the upper surfaces of the cross beams are substantially flush with the upper surfaces of the longitudinal beams.

40. A platform structure as claimed in any of claims 29 to 39, in which at least one pair of adjacent longitudinal beams, between an adjacent pair of cross beams, have longitudinal recesses which face each other, for receiving a cable support tray.

41. A platform structure as claimed in any of claims 29 to 40, in which at least one of the cross beams has at least one transverse aperture for the passage of a cable.

42. A platform structure as claimed in any of claims 29 to 41, in which the undersides of the platform units have projections for locating the platform units relative to the longitudinal beams.

43. A platform structure as claimed in any of claims 28 to 42, in which each longitudinal beam supports at least two platform units.

44. A platform structure as claimed in any of claims 29 to 41, in which the longitudinal beams are integral with the platform units.

45. A platform structure as claimed in any of claims 29 to 44, in which the adjacent side edge surfaces of adjacent platform units have, respectively, a key formation and a recess in which the key formation fits so as to resist relative vertical motion of the adjacent slab units.

46. A platform structure as claimed in any of claims 29 to 45, in which each platform unit is elongate in the direction away from the railway.

47. A platform structure as claimed in any of claims 29 to 46, in which the platform units include raised portions which are aligned to constitute a plinth to the rear of the platform structure.

48. A platform structure as claimed in any of claims 29 to 47, further comprising edge copers mounted side by side on the platform units.

49. A method of constructing a railway station platform structure, including the steps of:

(a) constructing foundations alongside the railway;

(b) constructing upstanding supporting members on the foundations; and

(c) mounting on the supporting members a prefabricated superstructure comprising cross beams mounted on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway, longitudinal beams on the cross beams, and platform units according to claim 1 on the longitudinal beams, the side edge surfaces of the platform units extending away from the railway and the front edge surfaces of the platform units extending along the railway beyond the ends of the cantilevered portions of the cross beams.

50. A method as claimed in claim 49, in which the longitudinal beams are combined with the platform units and step (b) includes mounting the cross beams on the supporting members and then mounting the longitudinal beams together with the platform units on the cross beams.

51. A method as claimed in claim 49, in which the cross beams, the longitudinal beams, and the platform units are combined to form separate prefabricated units of the superstructure, and step (b) includes mounting the prefabricated units of the superstructure on the supporting members.

52. A method of constructing a railway station platform structure, including the following steps:

(a) constructing foundations alongside the railway;

(b) constructing upstanding supporting members on the foundations;

(c) mounting cross beams on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway;

(d) mounting longitudinal beams on the cross beams; and

(e) mounting platform units according to claim 1 on the longitudinal beams so that the side edge surfaces of the platform units extend away from the railway and the front edge surfaces of the platform units extend along the railway beyond the ends of the cantilevered portions of the cross beams.