RU216156U1 - Sleeper for urban rail transport - Google Patents

Abstract

The utility model relates to the superstructure of railway tracks, namely sleepers and rail supports. A sleeper for railway transport includes a concrete beam with a trapezoidal cross-section of variable length, with reinforcing elements placed in it along its length, on the upper part of which there are two under-rail platforms for mounting rail fasteners, while dowels are installed on both sides of each under-rail platform for the upper part of the sleeper has stop surfaces for precise positioning of the rail fastening, while the height of the beam at its end part is 190 mm, the height of the beam in its central part is 160 mm, the length of the beam is 2500 mm, the width of the beam at its base is 250 mm, the width of the beam in its central part is 174 mm, the reinforcing elements are made with a diameter of 4-6 mm, placed in three rows, with four reinforcing elements in each row, while the distance between the upper and middle row is 25 -30mm, the distance between the middle and bottom row is 65-70mm, R the distance between the first and second element and the third and fourth element of each row is 25-30 mm, and the distance between the second and third element is 90 mm. The technical result consists in increasing the reliability of the reinforced concrete sleeper.

Description

The utility model relates to the superstructure of railway tracks, namely sleepers and rail supports.

From the prior art, a reinforced concrete sleeper for tram tracks with three horizontal platforms for installing paving slabs, made trapezoidal in cross section, reinforced with wire and/or rods and/or ropes, with upper end surfaces on both sides of it made horizontally, and the inner part, made horizontally along the entire length, while the inclination of the under-rail platforms provides the normative underslope of the rails. RF patent No. RU 167457U1, IPC E01B 3/32, published on 01/10/2017.

A sleeper of a tram rail track is known, containing an upper surface consisting of two extreme surfaces, a middle surface and connecting the extreme surfaces with the average surface of inclined surfaces made with a slope of 1:20, with each extreme surface made in the form of two parts - an inclined part and a horizontal a part passing from one side into an inclined surface, and from the other side - into an inclined part, and the middle surface of the sleeper is made horizontal and is located vertically below the horizontal parts of the outer surfaces. In addition, on the horizontal parts of the extreme surfaces and the middle surface, grooves are made for installing paving slabs, located symmetrically with respect to the vertical axis of the sleeper. RF patent No. RU 213612U1, IPC E01B 3/28, published 09/19/2022.

From the prior art, a technical solution is known, chosen as the closest analogue, which is a reinforced concrete sleeper for a tram track, made in the form of an all-block concrete beam of a periodic profile, reinforced in a stretched zone with wire, while four flat horizontal platforms are made on the upper surface of the sleeper, on which installed embedded parts for security devices and rails. RF patent No. RU 209887U1, IPC E01B 3/32, published on 03/23/2022.

The disadvantages of the presented known analogues are the insufficient strength of the sleeper during use and constant uneven operating loads due to the movement of railway transport on the railway track, as well as, for example, the constant movement of cars in the case of tram tracks. At the same time, the presented analogues do not provide the proper elasticity of the sleeper, which protects it from splitting under the rolling stock. In addition, the design, dimensions and features of the reinforcement of the presented sleepers do not prevent a change in the mechanical and physical properties of the reinforced concrete sleeper and contribute to an increase in the likelihood of fatigue failure of the reinforced concrete structure and a decrease in its endurance under repeated loading, and, as a result, less crack resistance and durability.

The objective of the proposed technical solution is to create a reinforced concrete sleeper with increased strength characteristics, increased durability and crack resistance.

The technical result of the claimed solution is to increase the reliability of the reinforced concrete sleeper.

The increase in reliability, in particular, is achieved by increasing the strength and crack resistance, strengthening the structure of the sleeper and rail fastening under repeated operational load, increasing the resistance to movement of the ballast layer and resistance to tearing the dowel out of the sleeper array, as well as increasing the durability of the sleeper.

The claimed technical result is achieved due to the fact that the sleeper for urban rail transport includes a concrete beam with a trapezoidal cross-section of variable length, with reinforcing elements placed in it along its length, on the upper part of which there are two under-rail platforms for mounting rail fasteners, while dowels for mating with track screws are installed on both sides of each under-rail platform, and stop surfaces are made on the upper part of the sleeper for precise positioning of the rail fastening, while the height of the beam at its end part is 190 mm, the height of the beam in its central part is 160 mm , the length of the beam is 2500 mm, the width of the beam at its base is 250 mm, the width of the beam in its central part is 174 mm, the reinforcing elements are made with a diameter of 4-6 mm, placed in three rows, with four reinforcing elements in each row, while the distance between the top and middle row is t 25-30 mm, the distance between the middle and bottom row is 65-70 mm, the distance between the first and second element and the third and fourth element of each row is 25-30 mm, and the distance between the second and third element is 90 mm. Preferably, the beam is made of B40 class concrete. Each reinforcing element is preferably a prestressed steel wire of a periodic profile.

A sleeper for urban railway transport includes a beam made of concrete, which is characterized by increased strength and wear resistance compared to wooden sleepers, as well as increased resistance to weather conditions and decay, which significantly extends the life of the sleeper, ensuring its high durability, and as a result, reliability. In addition, the sleeper beam made of concrete has a much larger mass than wooden sleepers, which makes the structure massive and increases its resistance to the movement of the ballast layer, which prevents stress in the fastening of the rail to the sleeper due to the high strength of the rail and its resistance to bending effects. , and also prevents the appearance of microcracks in the under-rail platform and tearing out of the traveling screws with dowels from the sleeper array, which ensures the durability and reliability of the proposed technical solution. At the same time, the increased strength characteristics of concrete prevent the rails from being pressed into the sleeper, changing the underslope angle of the under-rail surface and changing the gauge, which negatively affects the integrity and quality of the railway track. In addition, sleepers that include a beam made of concrete are easy to install and can be reused. Preferably, the sleeper beam is made of concrete class B40, characterized by a strength of 524 kgf/cm², which further increases the reliability of the sleeper. The use of concrete with a lower strength will reduce the strength characteristics of the sleeper, and with a higher one it is not advisable, since the reinforcement of the concrete beam increases the strength of the sleeper much more efficiently.

The trapezoidal cross section of the sleeper beam due to the fact that the lower base of the trapezoid is larger than the upper one and, as a result, the area of the lower surface of the beam is larger, provides a uniform optimal distribution of the pressure of the operational load exerted on the sleeper, which prevents deformation and stress in the material with subsequent formation and development cracks, that is, contributing to a reduction in material fatigue and an increase in its endurance, which significantly extends the life of the sleeper, increasing its durability and, thereby, reliability. In addition, the load distribution due to the trapezoidal section and the increase in the area of the lower surface of the sleeper reduces the pressure on the ballast layer, causing its mobility, leading to track theft and critical violations of the railway track.

The cross-section of the beam, which is variable along the length, contributes to the formation of additional stiffening ribs of the beam, reinforcing the structure, thereby increasing the sleeper's resistance to bending moment and its strength, which ensures durability and, as a result, reliability of the proposed technical device. In addition, the cross section of the beam, which is variable along the length, also contributes to the formation of a deepening of the central part of the sleeper relative to the extreme parts, which makes it possible to raise the rails relative to the horizontal plane of the ground and the ballast layer, thereby preventing wear of the central part of the sleeper due to touching it with the lower parts of the passing transport, which also ensures the durability and reliability of the sleeper. At the same time, the cross section of the beam, which is variable in length, makes it possible to lay the pavement slabs, when using a sleeper for forming a tramway, on the near-rail surfaces of the tramway and avoids chipping and abrasion of the sleeper surface by cars and pedestrians, which also ensures wear resistance and, as consequently, the reliability of the sleeper. By computational methods, as well as by experiment, it was determined that with a beam height at its end part equal to 190 mm, a beam height in its central part - 160 mm, a beam length - 2500 mm, a beam width at its base - 250 mm, a beam width in its central part - 174 mm, provides optimal strength characteristics of the sleeper, its rigidity and resistance to bending moments that occur during the operational load, which ensures the reliability of the sleeper. In addition, it is precisely these geometric parameters that increase the convenience of mounting the sleeper when forming a railway tramway and laying pavement slabs on top of it.

The presence on the upper part of the sleeper of two under-rail platforms for mounting rail fasteners, limiting the space for accommodating the rail and rail fastening parts, provides a single place for fixing the rail on the sleeper with the possibility of installing special under-rail shock-absorbing pads to reduce vibrations transmitted from the rail to the sleeper, leading to its destruction , which ensures the durability and reliability of the proposed device. In addition, a single location of the rail and its fastening on the under-rail platform allows you to maintain a constant track gauge of the railway track, which should have a constant value for the movement of railway transport to prevent the occurrence of stress in the rail fastening and, as a result, the appearance of microcracks in the sleeper, as well as to prevention of longitudinal displacement of the sleepers and theft of the track due to different positioning of the rail and unevenly distributed operational load on the extreme parts of the sleeper, which also ensures the reliability of the sleeper.

The execution of thrust surfaces on the upper part of the sleeper for precise positioning of the rail fastening ensures the exact location of the rail on the sleeper, which allows distributing the operational load from horizontal oscillations of the rail on the under-rail platform also into the concrete material of the sleeper and prevents the destruction of the sleeper and the formation of microcracks at the rail attachment point, which provides wear resistance and reliability of the proposed technical solution. In addition, the presence of a stop surface at the top of the sleeper ensures precise positioning of the rail fastening, which ensures a constant track gauge.

Reinforcing elements are placed along the length of the beam, giving the concrete structure high tensile and tensile strength, rigidity and crack resistance, thereby prolonging its service life under constant operating loads, providing high durability, wear resistance and, as a result, reliability of the proposed technical solution. From the experimentally obtained results of the production of sleepers with different parameters, it was revealed that the implementation of reinforcing elements with a diameter of 4-6 mm and their placement in three rows, with four reinforcing elements in each row, provides optimal strength characteristics of the sleeper, preventing fatigue failure of the sleeper and breaking adhesion of concrete and reinforcement, due to the parameters of the location of the reinforcing elements in the structure, which ensures high durability, wear resistance and, as a result, reliability of the sleeper. In addition, the distance between the top and middle row is 25-30mm, the distance between the middle and bottom row is 65-70mm, the distance between the first and second element and the third and fourth element of each row is 25-30mm, and the distance between the second and the third element equal to 90 mm, provides optimal rigidity of the sleeper structure, due to the formation of strong edges between the reinforcing elements, which ensures the strength and resistance to the bending moment of the entire sleeper, and thus the durability and reliability of the sleeper. The implementation of the reinforcing elements, their location and the distance between them form a reinforcement scheme that provides optimal strength characteristics of the sleeper, its tensile and bending strength, as well as the rigidity of the entire structure, which ensure the reliability of the proposed technical solution.

When the distance between the upper and middle row is less than 25 mm, the residual stress in the reinforcement after the concrete has cooled during the production of the sleeper leads to a strong compression of the concrete in the area between the reinforcing elements due to insufficient distance between them to relieve excessive stress, which subsequently leads to the formation of cracks in concrete between the reinforcing elements, which significantly reduces the strength and reliability of the sleeper. At the same time, if the distance between the upper and middle rows is more than 30 mm, it will lead to an increase in the fragility of the face between the reinforcing elements due to the large distance between them and the presence of a concrete bridge without prestressing, which, due to its properties, is more brittle than prestressed concrete around the reinforcing elements. elements, which also reduces the strength and crack resistance of the sleeper, and, as a result, its reliability. Making the distance between the middle and bottom row less than 65 mm leads to a strong compression of concrete in the area between the reinforcing elements due to the presence of residual stress in the reinforcement after the concrete has cooled during the production of the sleeper, which subsequently leads to the formation of cracks in the concrete between the reinforcing elements, which significantly reduces strength and reliability of the sleeper. At the same time, the distance between the middle and lower rows of more than 70 mm leads to the formation of a fragile concrete bridge between the reinforcing elements due to the large distance between them, which does not provide prestressing of the entire concrete and increase its strength, crack resistance and resistance to bending moment, which reduces the reliability of the sleeper . If the distance between the first and second element and the third and fourth element of each row is less than 25 mm, the residual stress in the reinforcement during the production of the sleeper will lead to strong compression of the concrete between the reinforcing elements due to insufficient distance between them to relieve excessive stress, which subsequently leads to the formation cracks in concrete between the reinforcing elements, which significantly reduces the strength and reliability of the sleeper. At the same time, making the distance between the first and second element and the third and fourth element of each row more than 30 mm will lead to an increase in the fragility of the edge between the reinforcing elements due to the presence of a concrete bridge without prestressing due to the large distance between the reinforcing elements, which, due to its properties, has greater fragility than prestressed concrete around the reinforcing elements, which also reduces the strength and crack resistance of the sleeper and, as a result, its reliability.

The implementation of reinforcing elements with a diameter of less than 4 mm and placing them in three rows, four elements in each and at the above distances between the rows of reinforcing elements corresponding to the reinforcement scheme, will lead to insufficient strength of the reinforced concrete structure when exposed to bending loads, which will reduce wear resistance and, thus the most reliable sleeper. In addition, when using reinforcing elements with a diameter of 6 mm and placing them in three rows, four elements in each and at the specified distances between the rows of reinforcing elements corresponding to the reinforcement scheme, it will increase the risk of fatigue stress in the sleeper and its destruction along the adhesion surface of the reinforcement and concrete, which will reduce the wear resistance and thus the reliability of the sleeper. Thus, a change in any of the geometric parameters of the reinforcement scheme will inevitably lead to a change in all other parameters to ensure the optimal rigidity of the structure, its strength characteristics and reliability.

The presence of dowels on both sides of each under-rail platform for mating with track screws and, due to the damping of vibrations of the track connection during the passage of vehicles along the railway track, prevents the occurrence of cracks in the under-rail zone, which ensures the durability and wear resistance of the device, and as a result, reliability. In addition, the embedded element, which is a dowel, further increases the manufacturability of the sleeper, and, unlike the spike connection, makes it easy to install a spring terminal on the rail fastening that prevents track theft, due to which the sleepers are longitudinally displaced relative to each other, which violates the structure of the railway track and extremely dangerous when passing through such a section of transport, which can lead to its derailment.

Preferably, each reinforcing element is a prestressed steel wire of a periodic profile, which, due to the prestressing during the manufacture of the sleeper beam, further increases the resistance of the beam to bending stresses, and also increases its crack resistance, by transferring the prestressing reinforcement to the concrete so that when it cools, it becomes compressed , which allows you to partially or completely eliminate tensile stresses from the operational load, which further increases the durability and, as a result, the reliability of the sleeper. The use of steel wire as a reinforcing element due to its high mechanical characteristics and high tensile strength increases the strength of the concrete beam, which further increases the durability and, thus, the reliability of the proposed technical solution. The periodic profile of the steel wire further increases the adhesion strength of the reinforcement to concrete and by increasing the surface area of the wire due to the uneven profile, protrusions and depressions on the surface of the wire, which also prevents the longitudinal movement of the wire inside the beam, in contrast to a completely smooth surface and a decrease in its strength and crack resistance, which further increases the reliability of the device.

Further, the proposed technical solution is explained with the help of figures, which shows one of the possible options for the execution of the sleeper.

In FIG. 1 shows a side view of the sleeper with a fragment of the under-rail platform in section.

In FIG. 2 shows a view of the sleeper from above.

In FIG. 3 shows sectional view A-A.

The numbers in the figures represent:

- under-rail platform (1);

- thrust surface (2);

- dowel (3);

- reinforcing element (4).

Further, with reference to the figures, one of the preferred embodiments of the proposed technical solution is described.

A sleeper for urban railway transport includes a concrete beam with a trapezoidal cross-section of variable length, on the upper part of which there are two under-rail platforms (1) for mounting rail fasteners, as well as stop surfaces (2) for precise positioning of the rail fastener, while from two On the sides of each under-rail platform (1), dowels (3) are installed for mating with track screws. In the concrete beam of the sleeper along its length, reinforcing elements (4) with a diameter of 4-6 mm are placed in three rows, with four reinforcing elements in each row, while the distance between the upper and middle rows is 25-30 mm, the distance between the middle and the bottom row is 65-70 mm, the distance between the first and second element and the third and fourth element of each row is 25-30 mm, and the distance between the second and third element is 90 mm. The beam height at its end part is 190 mm, the beam height in its central part is 160 mm, the beam length is 2500 mm, the beam width at its base is 250 mm, the beam width in its central part is 174 mm. Preferably, the beam is made of B40 class concrete. Each reinforcing element (4) is preferably a prestressed steel wire of a periodic profile.

When operating sleepers for railway transport installed on the ballast layer, two rails are placed on them and positioned in the under-rail area (1). The thrust surfaces (2) make it possible to clearly position the rail on the under-rail platform (1) and prevent the horizontal displacement of the rail along the sleeper. The rails are fixed on the sleeper by means of track screws, which are screwed into dowels (3) installed in the under-rail platform (1). In addition, a spring-loaded anti-theft terminal can be installed on the rail fastening to prevent theft of the sleepers. The sleeper for urban railway transport is made in the form of a beam made of B40 class concrete with reinforcing elements (4) installed in it, each of which is a prestressed steel wire of a periodic profile, which provides high strength and crack resistance of the sleeper.

The proposed technical solution can be used to form a railway track for urban transport. The device is characterized by increased reliability, in particular strength, crack resistance and durability.

The presented figures, description of the design and use of sleepers for railway transport do not exhaust the possible options for execution and do not limit in any way the scope of the proposed technical solution. Other versions are possible within the scope of the claimed formula.

Claims (3)

1. A sleeper for urban rail transport, including a concrete beam with a trapezoidal cross-section of variable length, with reinforcing elements placed in it along its length, on the upper part of which there are two under-rail platforms for mounting rail fasteners, while on both sides of each under-rail the platform is equipped with dowels for mating with track screws, and on the upper part of the sleeper there are thrust surfaces for precise positioning of the rail fastening, characterized in that the height of the beam at its end part is 190 mm, the height of the beam in its central part is 160 mm, the length of the beam is 2500 mm, the width of the beam at its base is 250 mm, the width of the beam in its central part is 174 mm, the reinforcing elements are made with a diameter of 4-6 mm, placed in three rows, with four reinforcing elements in each row, while the distance between top and middle row is 25-30 mm, the distance between the middle and bottom m side by side is 65-70 mm, the distance between the first and second element and the third and fourth element of each row is 25-30 mm, and the distance between the second and third element is 90 mm. 2. A sleeper for urban rail transport according to claim 1, characterized in that the beam is made of B40 class concrete. 3. A sleeper for urban rail transport according to claim 1, characterized in that each reinforcing element is a prestressed steel wire of a periodic profile.

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