Process for laying a railroad-subway superstructure without ballast and apparatus for producing said superstructure

Abstract

 The process for laying a railroad-subway superstructure without ballast consists in designing prefabricated components which, once assembled in a line, allow to build railroad routes with a precision in the range of one millimeter without having to perform any adaptation work. The apparatus for producing the superstructure comprises at least one concrete-mixing system (2), at least one casting line (3) defined by a plurality of mutually aligned and independent forms (4), at least one preparation lane (25) for the transverse compression of the platforms (7) and their advancement for sequentially performing completion and checkout operations on them, and means (30) for storing the platforms (7).

Description

[0001] The present invention relates to a process for laying a railroad-subway superstructure without ballast and to an apparatus for building said superstructure.

[0002] As is known, in conventional railroads, made either with wood sleepers or with reinforced-concrete ties, it is necessary to perform periodic maintenance of the ballast approximately every year and to replace it completely roughly every ten years.

[0003] New solutions have been developed and implemented in order to obviate the above problems; by not using the ballast, these solutions allow, under equal conditions of the conventional railroad, to avoid expensive and troublesome maintenance interventions especially in the presence of particular difficult environmental conditions such as tunnels and bridges.

[0004] In a currently preferred embodiment, the main elements which constitute the railroad without ballast are as follows.

[0005] Prestressed reinforced concrete platforms, which have the purpose of transferring the loads transmitted by the rail to the foundation, and then to the ground, so as to provide a sufficiently elastic stable support for the rails.

[0006] The foundation, made of a concrete slab, which provides a monolithic and sufficiently rigid uniform support for the prefabricated platforms.

[0007] The rubber plates for the insulation of the platforms and the rail coupling elements to provide the track.

[0008] The technical aim of the present invention is to provide a process for laying a railroad-subway superstructure without ballast and an apparatus for building said superstructure which allow to build tracks having high technical characteristics, including for example high route stability, both vertically and horizontally, even with a static load of 25 tons per axle traveling at a speed close to 250 kilometers per hour.

[0009] Within the scope of this aim, an important object of the invention is to provide a process for laying a railroad-subway superstructure without ballast, and an apparatus for building said superstructure which allow reduced maintenance interventions which can be reduced to simple shimmings of the coupling elements.

[0010] Another object of the invention is to provide a process and an apparatus which allow to obtain high elasticity of the entire system in order to effectively reduce both noise and transmitted vibrations.

[0011] Not least object of the invention is to provide a process and an apparatus according to the invention which allow to obtain a reduced deterioration of the railroad, which is designed for a commercial life of 50 years, except for the rails and the replaceable parts of the coupling elements.

[0012] This aim, these objects and others are achieved by a process for laying a railroad-subway superstructure without ballast, characterized in that it consists in: producing on site, according to the datum points of the planned alignment, a foundation slab made of cast-in-place reinforced concrete, provided with retention means for the support and retention of a plurality of rail-supporting platforms; arranging, on said slab, topographic datum plates having known X,Y and Z coordinates; manufacturing and storing in the factory said platforms made of biaxially prestressed reinforced concrete, with the dimensions defined by said planned alignment and by the anchoring point, if any, of the rails on said platforms according to the curved portions and to the gauge changes of said alignment; resting said platforms on said slab, arranging them geometrically in space at a preset distance from said slab by virtue of means for adjusting their inclination; pre-fitting on said platforms said rails which define the track; determining points R on said rails, at said topographic plates, by measuring their planimetric and altitude coordinates 1X, 1Y and 1Z; comparing the coordinates X, Y and Z with the coordinates 1X, 1Y and 1Z and with the planned coordinates 2X, 2Y and 2Z of said points R; in performing appropriate planimetric and altitude movements of said platforms on said slab by virtue of said adjustment means in order to achieve the prescribed design tolerances of said route; and in injecting a cement-asphalt mix, filling the space between said platforms and said slab.

[0013] Conveniently, the railroad-subway superstructure without ballast is produced by means of an apparatus, which is also the subject of the present invention, which is characterized in that it comprises means for forming a preset amount of concrete; means for casting said concrete into forms in order to produce a plurality of platforms to allow, on said platforms, a longitudinal prestressing by means of strands of stabilized piano-wire steel, means being furthermore provided for the transverse prestressing of said platforms and their advancement for the sequential execution, on said platforms, of completion and checkout operations, as well as means for storing said platforms.

[0014] Further characteristics and the advantages of the invention will become apparent with the description of a preferred but not exclusive embodiment of a process for laying a railroad-subway superstructure without ballast and of an apparatus for building said superstructure according to the invention, both illustrated by way of non-limitative example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a prefabricated platform according to the invention, which illustrates the screws for its adjustment and the holes for the injection of the cement-asphalt mix;

Figure 2 is a schematic plan view of the apparatus for building the railroad-subway superstructure without ballast according to the invention;

Figure 3 is a more detailed view of the casting line of the apparatus; and

Figure 4 schematically illustrates the process for the laying of each platform according to the planned datum points of the alignment.

[0015] With reference to the above figures, the process according to the invention is performed by means of the following succession of steps.

[0016] Initially, in a per se known manner, the plan of the reference route provided by the employer, either the railroad or subway authority, is examined.

[0017] The planimetric and altitude measurement of the infrastructural elements affected by the route, such as tunnels, viaducts, embankments, cuttings and of any element which interferes with the track, is then performed.

[0018] Then a foundation slab made of cast-in-place reinforced concrete is produced on site according to the datum points of the planned alignment.

[0019] During the production of the slab, the retention means 50 for supporting and retaining a plurality of platforms are also produced in said slab; the rails will subsequently be connected to said platforms.

[0020] Topographic datum plates 51, usually four, having known X, Y and Z coordinates, are furthermore arranged on the slab.

[0021] While the slab is being produced, the platforms, made of reinforced concrete which is prestressed biaxially, i.e. longitudinally and transversely, are manufactured and stored in the factory.

[0022] The individual platforms are manufactured so as to allow to build the railroad route within the prescribed tolerances.

[0023] In other words, each platform is built according to the dimensions defined by the planned alignment and according to any movement of the individual rail fixing points within the platforms themselves, so as to provide curved portions and gauge variations where required.

[0024] The platforms are subsequently rested on the slab using mechanized equipment which removes them from the railroad cars which have reached the laying area by means of an auxiliary track or from wheeled vehicles which travel on adjacent roads.

[0025] The platforms are rested on the slab, spacing them from said slab by approximately 50 millimeters by virtue of means for adjusting their inclination and particularly by means of four adjustment screws 52 which are arranged perimetrically on each platform.

[0026] The rails which define the track are pre-assembled on the platforms which rest on the slab and, after measuring the planimetric and altitude coordinates 1X, 1Y and 1Z of the points R of the internal wing of the head of the rail which is closest to the related topographic plate, the coordinates X, Y and Z of the topographic plates are compared with the coordinates 1X, 1Y and 1Z of the points R of the rails and with the planned coordinates 2X, 2Y and 2Z of the points R.

[0027] At this point, adequate planimetric and altitude movements are performed, i.e. the leveling and the alignment of the platforms are checked in order to achieve the prescribed route planning tolerances.

[0028] Finally, a mix of cement-asphalt is injected in the appropriate holes 53 of each platform, thus filling the space between said platform and the slab.

[0029] Conveniently, the topographic plates are arranged on the slab proximate to its retention means and particularly at the ends of each platform.

[0030] It should be furthermore specified that prior to the injection of the cement-asphalt mix between the slab and the platforms, said platforms are longitudinally provided with formwork in order to prevent any leakage of mortar and allow, by virtue of the particular structure of the forms, which have vertical grooves, the escape of air through said forms and thus also be able to check the level of the cement-asphalt mix introduced.

[0031] Furthermore, in order to allow an easy and remunerative production and laying cycle, appropriate platform type sorting structures are provided; said platforms are furthermore stored vertically in a preset position according to the sequence of removal and laying depending on their planimetric dimensions, on their rail fixing points and on the gauge variation, if any, depending on the morphological structure of the route to be built.

[0032] It should furthermore be stressed that the dimensions of the passive and active frames are set so as to keep the tension levels within the maximum levels allowed for the intended design loads of the railroad superstructure without ballast.

[0033] In the same manner, the elastic devices for the anchoring of the rails and for the resting of the platforms are given such dimensions as to provide the most suitable dynamic characteristics in order to minimize vibrational and noise pollution generated by railroad traffic.

[0034] The apparatus for building the railroad-subway superstructure without ballast is also a subject of the present invention.

[0035] Particularly, the apparatus and the equipment for building the platforms comprise means for forming a preset amount of concrete, defined by a concrete-mixing apparatus 2 having high production capacity which is provided with two mixers 40 having a horizontal axis and is controlled by an electronic computer 41.

[0036] The apparatus is capable of providing indications related to the humidity of the aggregates and to the consistency of the mix, whereas an alphanumeric printer 42 records the doses of each mix and daily consumptions.

[0037] The apparatus furthermore has means for casting the concrete in forms which comprise a casting line 3 constituted by a plurality of mutually aligned and independent forms and by a tensioning head 5 and an anchoring head 6.

[0038] The casting line is considerably long, in order to allow longitudinal prestressing, by means of strands of stabilized piano-wire steel, applied to the platforms 7 manufactured by means of the forms 4, by virtue of the possibility of allowing the individual forms to perform free longitudinal relative movements by means of low-friction supports.

[0039] The initial repositioning of the forms 4 is then obtained by using hydraulic jacks 8.

[0040] The apparatus furthermore has means 10 for performing the transverse prestressing of the platforms and their subsequent advancement in order to perform sequentially, on said platforms, the further completion and checkout operations, after the completion of which the platforms undergo a storage operation by virtue of storage means.

[0041] More in detail, the casting line 3 comprises means 20 for adjusting the lengths and positions of the regions suitable to receive the coupling elements of the rails and of the screws for their adjustment on the platforms.

[0042] In the casting line there are also means 21 for the laying and tensioning of the platform prestressing strands and means 22 for producing the transverse holes in order to apply transverse tension to said platforms.

[0043] On the casting line there are also means 23 for the mechanical packing of the concrete casting, which comprise for example sliding compressed-air vibrators, and means 24 for the curing of the concrete casting, defined by an insulated awning which allows the start of the nocturnal curing cycle with low-pressure vapors and at a maximum temperature of 55 degrees.

[0044] Once the curing cycle has ended and the prescribed mechanical characteristics of the concrete have been achieved, the platforms are subjected to the loosening of the strands with the aid of relaxation pistons and to the separation of said strands by cutting.

[0045] The apparatus furthermore provides a preparation lane 25 which is essentially constituted by a double supporting roller set which is used as platform advancement line; fixed treatment stations 26 are arranged to the sides of said line and allow to sequentially perform the operations for completing and checking the platforms.

[0046] The preparation lane in fact comprises, as already mentioned above, means 10 for performing transverse prestressing of the platforms and means 27 for connecting the coupling elements on the platforms in the preset positions prescribed by the design specifications.

[0047] The preparation lane furthermore comprises a device 28 for the automatic positioning and locking of the platforms in order to provide the prescribed gauge of the shoulders 29 of the platforms, their alignment in case of platforms for straight track or the relative movement of the shoulders 29 in case of platforms for curved track, according to the planned route.

[0048] Finally, the apparatus provides means 30 for storing the platforms, which are suitable to remove them from the preparation lane and deposit them, in a vertical position, numbered according to the railroad plan, in a prearranged manner within racks 31 arranged in organized yards for the completion of the setting of the platforms and to allow the immediate identification and removal thereof according to the plan of the railroad-subway route.

[0049] In this manner, the sequence of the loading of the platforms on the means of transport directed to the laying site, whether a railroad car or other vehicle, occurs according to the sequence in which the platforms are unloaded from the means of transport onto the slab according to the planned alignment.

[0050] The invention achieves the intended aim and objects and achieves important and numerous advantages.

[0051] In particular, the prestressed reinforced-concrete platforms are built and laid sequentially and in a preset manner as a function of the planned alignment datum points by virtue of their prior type-sorting, in order to allow economy and high productivity of the cycle for their production, storage and laying.

[0052] The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the present inventive concept.

[0053] All the details may furthermore be replaced with technically equivalent elements.

[0054] The materials employed, the shapes and dimensions may be any according to the requirements.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

1. Process for laying a railroad-subway superstructure without ballast, characterized in that it consists in: producing on site, according to the datum points of the planned alignment, a foundation slab made of cast-in-place reinforced concrete, provided with retention means for the support and retention of a plurality of rail-supporting platforms; arranging, on said slab, topographic datum plates having known X,Y and Z coordinates; manufacturing and storing in the factory, simultaneously with the building of said slab, said platforms made of biaxially prestressed reinforced concrete according to the dimensions of the datum points of said planned alignment and to the anchoring point, if any, of the rails on said platforms according to the curved portions and to the gauge changes of said alignment; resting said platforms on said slab, arranging them geometrically in space at a preset distance from said slab by virtue of means for adjusting their inclination; pre-fitting on said platforms said rails which define the track; determining points R on said rails, at said topographic plates, by measuring their planimetric and altitude coordinates 1X, 1Y and 1Z; comparing the coordinates X, Y and Z with the coordinates 1X, 1Y and 1Z and with the planned coordinates 2X, 2Y and 2Z of said points R; in performing appropriate planimetric and altitude movements of said platforms on said slab by virtue of said adjustment means in order to achieve the prescribed design tolerances of said route; and in injecting a cement-asphalt mix, filling the space between said platforms and said slab.

2. Process according to claim 1, characterized in that said topographic plates are arranged on said slab proximate to said retention means.

3. Process according to claim 1, characterized in that said adjustment means comprise four adjustment screws arranged perimetrically on each one of said platforms.

4. Process according to claim 1, characterized in that said platforms are stored vertically in a preset position according to the sequence of their removal and laying, according to their planimetric dimensions, to the points for fixing the rails thereon and according to the gauge variation, if any, depending on the morphological structure of said route.

5. Process according to claim 1, characterized in that said platforms, prior to the injection of said cement-asphalt mix, are provided with longitudinal formwork to prevent any leakage of said mix and simultaneously allow the vertical escape of the air comprised between each platform and said slab.

6. Apparatus for producing a railroad-subway superstructure without ballast, characterized in that it comprises means (2) for the forming of a preset amount of concrete, means (3) for the casting said concrete in formwork in order to produce a plurality of platforms (7) so as to allow, on said platforms, longitudinal prestressing by means of stabilized piano-wire steel strands, means (10) being furthermore provided for the transverse compression of said platforms (7) and for their advancement for the sequential execution, on said platforms, of completion and checkout operations, means (30) for the storage of said platforms being also provided.

7. Apparatus according to claim 6, characterized in that said means for the forming of a preset amount of concrete comprise at least one concrete-mixing apparatus (2), and in that said casting and formwork-applying means (3) comprise at least one casting line (3) which has a plurality of forms (4) which are mutually aligned and independent in order to allow, on said platforms (7), longitudinal prestressing by means of strands of stabilized piano-wire steel, said forms (4) being provided with low-friction supports for their free longitudinal movement and with hydraulic means for restoring their initial position after said longitudinal prestressing.

8. Apparatus according to claim 7, characterized in that said concrete-mixing apparatus comprises at least one mixer (40) with a horizontal axis which is controlled by an electronic computer (41) for controlling the humidity of the aggregates and the consistency and doses of each mix with the related daily consumptions.

9. Apparatus according to claim 7, characterized in that said casting line comprises means (20) for adjusting the lengths and the positions of the regions suitable to receive the coupling elements of the rails and of the screws for their adjustment on said platforms, means (21) for the laying and tensioning of said prestressing strands of said platforms, means (22) for producing transverse holes for the subsequent transverse tensioning of said platforms, means (23) for the mechanical packing of said concrete casting and means (24) for its curing.

10. Apparatus according to claim 7, characterized in that said preparation lane (25) comprises at least one double roller set for the conveyance of said platforms, means (10) for performing their transverse prestressing and means (27) for connecting the coupling elements on said platforms in the preset positions.

11. Apparatus according to claim 7, characterized in that said preparation lane comprises a device (28) for the automatic positioning and locking of said platforms for the precise execution of the shoulders (29) of said plates according to the preset railroad-subway route plan.

12. Apparatus according to claim 7, characterized in that said means (30) for the storage of said platforms (7) are suitable to deposit in a prearranged vertical position within racks (31) arranged in organized yards for the completion of the setting of said platforms for the immediate identification and removal of said platforms according to the plan of the railroad-subway route.

Drawing