Prefabricated through bridge for a railway

Abstract

The invention relates to a prefabricated concrete through bridge for a railway, with at least two Z-section prefabricated concrete beams and a concrete joining slab as support for the tracks, defining a train traffic space, the height of which is less than the upper horizontal portions of the prefabricated beams, which support closure and fencing elements, catenary posts and communication means, the prefabricated beams being supported at height by support means, which may be piers or horizontally arranged pier caps with a recessed fitting. The main advantage of the invention is a considerable saving in railway bridge construction time and cost, especially owing to the horizontally arranged pier caps with a recessed fitting, which are a very advantageous alternative to pergola structures.

Description

[0001] Prefabricated lower deck bridge for railways

[0002] This specification refers, as its title indicates, to a prefabricated concrete bridge with a lower deck for railways comprising at least two prefabricated concrete beams in the shape of a "Z" and a concrete connecting slab that serves as a support for the ballast, sleepers and tracks, defining a space for train circulation whose height is below the upper horizontal sections of the prefabricated concrete beams, which serve as a support for the closing and fencing elements, catenary poles and means of communication, the prefabricated concrete beams being supported in height by support means that may be support piles, or horizontally arranged lintels with a lowered fit, as an advantageous alternative to pergola structures.

[0003] Field of the invention

[0004] The invention relates to the field of prefabricated railway bridges, especially those with a lower deck.

[0005] Current state of the art

[0006] Given the current state of technology, it is common to build bridges or viaducts to allow railway tracks to cross terrain features such as valleys, rivers, or ravines, or to cross roads or other railway lines.

[0007] In some cases, constructions such as that described in CN201722594U “Extradosed railway cable-stayed bridge" are used, which combine beams and cable-stayed girders, or more conventionally using closed beam structures, conventional T or H, and a support deck for the railway tracks, as for example described in CN104818670A “Waterproof structure of high speed railway ballastless concrete bridge continuous concrete carriageway plate system" and in KR101161628B1 “Girder railway bridge having a rail fastener 1 These structures are complex and costly, both in terms of time and money, and require the train to run on top of the deck, without side protections, which must be added to the construction.

[0008] When elevated crossings are made over roads or other railways, these problems are exacerbated, as the unique characteristics of railway tracks require curves with very small maximum angles, especially for high-speed trains. This necessitates very wide layouts. This does not allow for optimal angles when crossing over roads or other railways. Instead, the elevated crossing is often made at a small angle, requiring the use of "pergola"-type support structures, as it is not possible to install support columns along the track layout below. "Pergola"-type support structures consist of a corridor flanked by a large number of vertical columns (called pillars) that support longitudinal beams (sleepers), which support the beams that in turn support the deck on which the railway tracks are laid.The particular complexity of this type of crossing, represented in Figures 10 and 11, requires these pergola-type support structures to have a large number of pillars and sleepers, which must be installed on-site when the lower railway tracks are not in operation. This entails high costs in both time and materials, in addition to a significant impact on time, resulting in a high economic cost for each crossing. Obviously, this type of structure is ideal for avoiding or replacing.

[0009] Some improved proposals for railway bridges using bottom decks are known, such as CN212316678U “Railway ballast tank on integral steel bridge deck of railway bridge" and CN206941391 U “Railway ballast groove on whole steel bridge panel of iron road bridge roof beam", but they involve multiple pieces to be joined, which does not save much, and they do not present alternatives to the “pergola” type support structures.

[0010] There are also some known beams that are joined together to form larger beams, such as ES1279249 “Prefabricated beam with large section”, ES2254211 “Prefabricated beam in two halves”, or ES2193852 “Prefabricated beam for supporting viaducts” but these are structures designed to be closed at the top, by means of a deck or other beam, to form beams or closed spaces, and are not suitable for laying railway tracks, and they do not provide lateral horizontal spaces that can be used for platforms, fences or auxiliary elements. Nor do they provide any solution for “pergola” type support structures.

[0011] There are also known solutions such as the one described in patent KR20110031816A, "Through bridge construction method by PSC side beam and slab," which presents a trough bridge construction method using a PSC-type side beam (which can be L-beams or H-beams) and a slab for installing a rail on the slab of a railway bridge. A slab is formed between the inner lower parts of the beam on both sides to integrate with the slab on both sides. In this solution, the lower slab for laying the tracks and for train traffic is the same one that forms the floor, connecting the beams together. This causes problems of insufficient rigidity and the transmission of vibrations from the passing train directly to the bridge structure, which is detrimental to its durability. Furthermore, the use of L- or H-beams does not allow, nor is it intended to support enclosure and fencing elements, catenary poles, and communication media.

[0012] Description of the invention

[0013] To solve the current problems in the construction of bridges or viaducts for railways, the prefabricated lower deck bridge for railways object of the present invention has been devised, which comprises

[0014] - at least two independent precast concrete beams, prefabricated and transportable separately, with a "Z" section defined by an upper horizontal section, a lower horizontal section along all or most of its length and a vertical wall joining them, arranged symmetrically in such a way that their lower horizontal sections are arranged adjacently in the same horizontal plane and at the same height, and

[0015] - connecting means between the prefabricated concrete beams comprising a concrete slab, made in situ, horizontally arranged in a solidary manner at the bottom of the interior hollow space defined by the prefabricated concrete beams, and whose height is below the upper horizontal sections of the prefabricated concrete beams, the concrete slab being the support for a ballast layer on which the sleepers and tracks are located, below the upper horizontal sections of the prefabricated concrete beams, the upper horizontal sections of the prefabricated concrete beams being the support for the closing and fencing elements, catenary poles and means of communication, and the prefabricated concrete beams being supported in height by support means.

[0016] In those sections of the bridge where possible, the means of supporting the precast concrete beams in height consist of one or more support piles, or shafts, located under the lower horizontal sections of the precast concrete beams and joined to them in a solid manner, in which case the concrete slab is placed on the lower horizontal sections of the precast concrete beams.

[0017] In those sections of the bridge where an elevated crossing over an existing railway or road section is necessary, of any width, the means of supporting the height of the prefabricated concrete beams consist of one or more horizontally arranged lintels, each located on at least two support columns,

[0018] - each lintel having a housing, consisting of a recess on its upper face of greater width than the width defined by the distance between the vertical walls of the prefabricated concrete beams on their external part, and

[0019] - by arranging the prefabricated concrete beams with a lower recess, eliminating the lower horizontal sections, in the area coinciding with the lintel housing, in such a way that the side walls of the prefabricated concrete beams rest directly on the bottom of the housing, in this case the concrete slab being arranged to fill the lintel housing, both on the inside of the side walls of the prefabricated concrete beams and on their outside, up to the same height as the lintel.

[0020] The lintel width will be adjusted to the width of the existing railway or road section, and the precast concrete beams and their housing will be arranged horizontally anywhere above the lintel to maintain the required crossing angle, avoiding and replacing traditional pergola structures. To this end, the support columns will preferably be located at the ends of the lintel, and on both sides of the existing railway or road section that the bridge must span. However, additional support columns can optionally be added where necessary and possible due to the configuration of the crossing.

[0021] An alternative embodiment of the invention is provided, comprising one or more auxiliary flat beams, located in the same plane and height as the lower horizontal sections of the prefabricated concrete beams, also covered by the concrete slab, defining an interior hollow space of a width suitable for two or more sets of sleepers and tracks. This alternative embodiment is compatible with both support on support piles and lintels, and allows for the construction of bridges for double or multiple tracks. The prefabricated concrete beams have a length suitable for separate transport and will be joined together by transverse joints, forming a single continuous beam of the length required for the bridge.

[0022] Advantages of the invention

[0023] This prefabricated lower-deck railway bridge presented here offers multiple advantages over currently available structures, the most important of which is that it allows for rapid and cost-effective construction of bridges, with minimal time and impact on existing structures to be spanned.

[0024] Another important advantage is that it provides a valid construction alternative to pergola-type support structures thanks to the horizontally arranged lintels with a recessed fit, significantly reducing costs, materials, and construction time.

[0025] It is also important to highlight the significant savings in both time and money that come with using a majority of precast concrete elements in construction.

[0026] It is also worth noting that this solution structurally integrates upper horizontal sections into the prefabricated concrete beams, which serve as support for the enclosure and fencing elements, catenary poles, and communication means, acting as platforms or sidewalks, facilitating and simplifying the construction process.

[0027] Another important advantage of this construction is that both the ballast and the sleepers and rails remain inside the space defined by the beams, making the train partially circulate inside them, in a position much lower than that obtained in conventional construction systems, resulting in both greater protection of the tracks against atmospheric elements, and greater safety of high-speed train circulation, since in the event of accidental derailment, the side walls of the tracks would act as a stop, limiting its movement and minimizing possible damage from this exit from the track.

[0028] It should also be noted that the use of a concrete slab independent of the connection between the beams as a support for the ballast layer improves the rigidity of the connection and isolates the bridge structure from vibrations caused by the passage of trains, increasing its durability and reliability compared to known solutions that use the concrete of the structure itself as a support for the ballast.

[0029] Likewise, it is important to highlight that the use of Z-shaped beams, as opposed to the more common H or L-shaped beams, provides the additional advantage of enabling the use of the upper flat surface as a service walkway, sidewalk, and to support enclosure and fencing elements, catenary poles and communication media.

[0030] Description of the figures

[0031] In order to better understand the object of the present invention, in the attached drawing, by means of figures 1 to 9, a preferential practical embodiment of a prefabricated lower deck bridge for railways is represented.

[0032] In this plan, figure -1- shows a cross section of a bridge section on a support pile or shaft.

[0033] Figure -2- shows a cross-section of a bridge span over a lowered lintel on supporting columns, in an example with the railway track located approximately in the centre of the lintel.

[0034] Figure -3- shows a cross-section of a bridge span over a lowered lintel on supporting columns, in an example with the railway track located to the right of the lintel.

[0035] Figure -4- shows a cross-section of a bridge span over a lowered lintel on supporting columns, in an example with the railway track located to the left of the lintel.

[0036] Figure -5- shows a perspective view of the beams, detailing a lower recess for the lintel.

[0037] Figure 6 shows a side view of the beams, detailing a lower recess for the lintel. Figure 7 shows a side view of a bridge span, above a support pier and above a lintel.

[0038] Figure -8- shows a plan view of a bridge built for the overpass over existing railway track sections, alternatively to a pergola.

[0039] Figure -9- shows a cross section of a bridge span on a support pile or shaft, in an alternative embodiment, with an auxiliary flat beam, to accommodate a double railway track.

[0040] Figures 10 and 11 illustrate the construction technique currently used for building elevated-deck railway bridges. Figure 10 shows an elevation view of conventional pergolas constructed for an overpass over sections of existing railway tracks.

[0041] Figure -11- shows a plan view of conventional pergolas made for the overpass over existing railway track sections.

[0042] Preferred embodiment of the invention

[0043] The constitution and characteristics of the invention may be better understood with the following description made with reference to the attached figures.

[0044] As can be seen in Figure 1, it is illustrated how the prefabricated lower deck bridge for railway comprises

[0045] - at least two independent, prefabricated and separately transportable precast concrete beams (1), with a "Z" section defined by an upper horizontal section (2), a lower horizontal section (3) along all or most of the length of the precast concrete beam (1), and a vertical wall joining them, arranged symmetrically such that their lower horizontal sections (3) are arranged adjacently in the same horizontal plane and at the same height, and

[0046] - connecting means between the prefabricated concrete beams (1) comprising a concrete slab (4), made in situ, horizontally arranged in a solidary manner at the bottom of the interior hollow space defined by the prefabricated concrete beams (1), and whose height is below the upper horizontal sections (2) of the prefabricated concrete beams (1), the concrete slab (4) being the support for a ballast layer (5) on which the sleepers and tracks (6) are located, below the upper horizontal sections (2) of the prefabricated concrete beams (1), the upper horizontal sections (2) of the prefabricated concrete beams (1) being the support for the closing and fencing elements (7), catenary poles and means of communication, and the prefabricated concrete beams (1) being supported in height by support means.

[0047] The means of joining the prefabricated concrete beams may additionally comprise other known joining methods, such as joining reinforcements by mechanical means, welding, through bars, intermediate pieces, etc.

[0048] In those sections of the bridge where possible, as illustrated in figure 1 , the means of supporting the height of the prefabricated concrete beams (1) consist of one or more support piles (8) located under the lower horizontal sections (3) of the prefabricated concrete beams (1) and joined to them in a solidary manner, in this case the concrete slab (4) being arranged on the lower horizontal sections (3) of the prefabricated concrete beams (1). In this way, the concrete slab (4) made in situ serves to join the prefabricated concrete beams (1) together and to form a stable support slab for the location on it of the ballast layer (5) and the sleepers and tracks (6).

[0049] In those sections of the bridge where an elevated crossing over an existing railway or road section is necessary, of any width, as illustrated in figures 2, 3 and 4, the means of supporting the height of the prefabricated concrete beams (1) consist of one or more horizontally arranged lintels (9), each of them located on at least two support columns (10), - each lintel having a housing (11), consisting of a recess on its upper face of greater width than the width defined by the distance between the vertical walls of the prefabricated concrete beams (1) on their external part, and

[0050] - arranging the prefabricated concrete beams (1) with a lower recess (12) eliminating the lower horizontal sections (3) in the longitudinal section of the prefabricated concrete beam (1) coinciding with the housing (11) of the lintel (9), in such a way that the side walls of the prefabricated concrete beams (1) rest directly on the bottom of the housing (11), as illustrated in figures 5, 6 and 7, in this case the concrete slab (4) being arranged to fill the housing (11) of the lintel (9), both on the inside of the side walls of the prefabricated concrete beams (1) and on its outside, up to the same height as the lintel (9). In this way, the concrete slab (4) made in situ serves both to secure the prefabricated concrete beams (1) to the lintel (9) and to form a stable support slab for the placement of the ballast layer (5) and the sleepers and tracks (6) on it.

[0051] As illustrated in Figure 8, the width of the lintel (9) will be adjusted to the width of the existing railway or road section, and the prefabricated concrete beams (1) and their housing (11) will be horizontally arranged anywhere on the lintel (9), to maintain the necessary crossing angle, avoiding and replacing the traditional pergola structures. For this purpose, the support columns (10) will preferably be located at the ends of the lintel (9), and on both sides of the existing railway or road section that must be crossed by the bridge, although it is optionally possible to add additional support columns (10) where necessary and possible due to the configuration of the crossing.

[0052] An alternative embodiment of the invention is provided, illustrated in Figure 9, comprising one or more auxiliary flat beams (14), located in the same plane and height as the lower horizontal sections (3) of the prefabricated concrete beams (1), also covered by the concrete slab (4), defining an interior hollow space of a width suitable for two or more sets of sleepers and tracks (6). This alternative embodiment is compatible with support on support piles (8) as well as on lintels (9), and allows the construction of bridges for double or multiple tracks. If it is constructed on lintels (9), the housing (11) will be wider, and in that section, coinciding with the lower recesses (12) of the prefabricated concrete beams (1), no auxiliary flat beam (14) will be placed, but will be replaced by the concrete slab (4).The prefabricated concrete beams (1) have a length suitable for separate transport, and will be joined together by transverse joints (13), with their corresponding expansion joints where necessary, forming a single continuous beam of the length required by the bridge.

[0053] To help better understand the nature of the invention, Figures 10 and 11 illustrate the traditional construction technique currently used for the construction of elevated deck railway bridges, which is part of the state of the art. Thus, Figure -10- shows an elevation view of conventional pergola structures (15) made for the flyover over sections of existing railway tracks, showing the construction complexity required for a similar crossing, and how the tracks are located in a very elevated position above the construction elements.

[0054] Figure -11- shows a plan view of conventional pergola structures (15) made for the overpass over existing railway track sections.

[0055] The person skilled in the art will readily understand that he or she may combine features of different embodiments with features of other possible embodiments, provided that such a combination is technically possible.

[0056] All information relating to examples or embodiments forms part of the description of the invention.

Claims

CLAIMS 1 - Prefabricated lower deck bridge for railway, characterized in that it comprises - at least two independent, prefabricated and separately transportable precast concrete beams (1), with a "Z" section defined by an upper horizontal section (2), a lower horizontal section (3) along all or most of the length of the precast concrete beam (1), and a vertical wall joining them, arranged symmetrically such that their lower horizontal sections (3) are arranged adjacently in the same horizontal plane and at the same height, and - connecting means between the prefabricated concrete beams (1) comprising a concrete slab (4), made in situ, horizontally arranged in a solidary manner at the bottom of the interior hollow space defined by the prefabricated concrete beams (1), and whose height is below the upper horizontal sections (2) of the prefabricated concrete beams (1), the concrete slab (4) being the support for a ballast layer (5) on which the sleepers and tracks (6) are located, below the upper horizontal sections (2) of the prefabricated concrete beams (1), the upper horizontal sections (2) of the prefabricated concrete beams (1) being the support for the closing and fencing elements (7), catenary poles and means of communication, and the prefabricated concrete beams (1) being supported in height above the ground by support means. 2 - Prefabricated lower deck bridge for railways, according to the previous claim, characterized in that the height support means of the prefabricated concrete beams (1) consist of one or several support piles (8) located under the lower horizontal sections (3) of the prefabricated concrete beams (1) and joined to them in a solidary manner, in this case the concrete slab (4) being arranged on the lower horizontal sections (3) of the prefabricated concrete beams (1). 3 - Prefabricated lower deck bridge for railways, according to any of the previous claims, characterized in that it comprises one or more auxiliary flat beams (14), located in the same plane and height as the lower horizontal sections (3) of the prefabricated concrete beams (1), covered by the concrete slab (4), defining an interior hollow space of a width suitable for two or more sets of sleepers and tracks (6). 4 - Prefabricated lower deck bridge for railways, according to claim 1, characterized in that the height support means of the prefabricated concrete beams (1) consist of one or several horizontally arranged lintels (9), each of them located on at least two support columns (10), - each lintel having a housing (11) consisting of a recess on its upper face of greater width than the width defined by the distance between the vertical walls of the prefabricated concrete beams (1) on its external part, and - arranging the prefabricated concrete beams (1) with a lower recess (12) eliminating the lower horizontal sections (3) in the longitudinal section of the prefabricated concrete beam (1) coinciding with the housing (11) of the lintel (9), in such a way that the side walls of the prefabricated concrete beams (1) rest directly on the bottom of the housing (11), in this case the concrete slab (4) being arranged filling the housing (11) of the lintel (9), both on the inside of the side walls of the prefabricated concrete beams (1) and on its outside, up to the same height as the lintel (9). 5 - Prefabricated lower deck bridge for railways, according to claim 4, characterized in that the prefabricated concrete beams (1) and their housing (11) are horizontally arranged anywhere above the lintel (9). 6 - Prefabricated lower deck bridge for railways, according to any of claims 4 and 5, characterized in that the support columns (10) are located at the ends of the lintel (9), and on both sides of the existing railway or road section that must be crossed with the bridge. 7 - Prefabricated lower deck bridge for railways, according to any of the previous claims, characterized in that the prefabricated concrete beams (1) have a length suitable for separate transport, being joined together by transverse joints (13) forming a single continuous beam of the length required by the bridge.

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