RU2774897C1 - Reinforced concrete universal sleep for anchor type fastening - Google Patents

Abstract

FIELD: railway track structure.

SUBSTANCE: invention relates to the field of the upper structure of the railway track, in particular to universal reinforced concrete sleepers. The sleeper is made in the form of a beam with a trapezoidal cross-section variable along the length. An anchor with shanks is placed in the area of ​​the under-rail base of the sleeper. Shanks are directed at an angle of 15-75° to the vertical axis. The cross section of the shank at the end sections increases. The geometry of all elements of the lower part of the anchor is a set of transition curves of large radius. The jumper is made in the form of an arched type structure. The sleeper bar is reinforced with high-strength wire. The wire is arranged in four rows in the horizontal plane and six rows in the vertical plane, symmetrically about the vertical axis of the cross section in two rows. The lower rows of wires are fixed with rigid elements at a distance of 120-250 mm from the end surfaces of the sleepers.

EFFECT: crack resistance of the sleepers is increased.

1 cl, 1 tbl, 4 dwg

Description

The technical field to which the invention belongs

The invention relates to the superstructure of the rail track, including public railways, trunk lines, including those with increased axial loads, high traffic density, high-speed lines, sidings, as well as urban rail transport. The technical result of the invention is increased reliability, crack resistance and durability, which ensures the repeated use of the product after performing track repairs without restrictions. The scope of the invention includes main railway lines, including high-speed, public and non-public railway lines, access rail tracks of industrial enterprises, rail tracks in tunnels, subways, tram tracks, as well as rail transport in urban agglomerations.

State of the art

A technical solution is known - a useful model of a universal reinforced concrete sleeper, including a bar with a variable length trapezoidal cross section with upper surfaces for accommodating rail fastening parts with embedded or anchor parts, reinforced in four vertical rows with wires arranged symmetrically in two rows relative to the vertical axis of the transverse trapezoidal section , the reinforcement of the beam is made in the form of 16 high-strength wires, with each first row containing five wires, and each second row containing three wires, and the dimensions of the sleeper at the end have, respectively, the nominal dimensions of the trapezoidal section in height 190 mm, in the width of the upper and lower bases 213 mm and 300 mm, and the middle part of the trapezoidal section has nominal dimensions of 185 mm, 178 mm and 235 mm, respectively, and in the under-rail section, the nominal dimensions of the sleeper are 225 mm, 185 mm and 277 mm, respectively. Each rail fastening unit is made of two plastic anchor parts with a threaded hole, in which metal screws are placed to transfer the clamping force to the elastic terminals and the rail foot. Each rail fastening unit can also be made of two anchors in the form of metal parts of variable cross section with a protruding part above the concrete surface to accommodate elastic clamps and transfer clamping force from the clamps to the rail foot. (RU (11) 93 812 (13) U1, 05/10/2010). This sleeper design is taken as analogue.

The disadvantages of this technical solution are as follows.

The rail fastening unit of the sleeper is made of two anchors in the form of metal parts of variable cross section with a protruding part above the concrete surface to accommodate elastic terminals (the design is described in patent RU 2335593 C1, 05/18/2007). This design of the anchor includes downwardly directed shanks of considerable length, as well as fillets with relatively small transition radii from the shanks to the bridge connecting the anchor heads, which contributes to local stress concentration in operation in the sleeper in the areas of the end of the shanks, as well as in the contact zones of the sleeper material with anchor elements with small radii.

Operating experience of a sleeper of this design indicates the formation of longitudinal cracks in the end sections of the sleeper. These defects are a consequence of the uneven stress-strain state of the sleeper in operation with the concentration of stresses in the end sections of the concrete of the sleeper, which leads to the formation of cracks in these areas. The uneven stress state in the end sections of the sleeper is due to the presence of stress concentrators in the contact zones of the sleeper material with the ends of the anchor shanks and in the areas of the anchor where there are zones with small radii, as well as to the uneven deformation processes occurring in the reinforcement, which is a high-strength wire located in cross section in vertical rows.

Disclosure of invention

The technical result of the claimed invention is the elimination of these disadvantages, namely the increase in strength, operational reliability and durability of the sleeper during the entire period of operation on the basis of:

- the use of an anchor of a new design, characterized by a change in the geometry of the anchor in its lower part, deviation of the directions of the shank from the vertical axis by an angle in the range from 15 to 75 degrees, a decrease in the length of the shank having an increase in the cross section at the end sections;

- reinforcing the sleeper in four vertical rows ^{with 24} high-strength wires arranged symmetrically in two rows relative to the vertical axis of the cross trapezoidal section of the sleeper;

- fixing four, two adjacent in the lower rows, high-strength steel wires with rigid elements that reduce deformation processes in the end sections of these wires and in concrete at the end sections of the sleeper in operation.

To achieve the above technical result, a universal reinforced concrete sleeper is proposed, including a beam with a trapezoidal cross-section variable in length with upper surfaces for placing anchor rail fastening parts, while:

an anchor with shanks located in the lower part of the anchor, located in the sleeper, directed at an angle to the vertical axis in the range from 15 to 75 ° and having an increase in the cross section at the end sections, with the geometry of all elements of the lower part of the anchor representing is a set of transition curves of large radius, and the geometry of the anchor lintel corresponds to the geometry of the arch type structure;

the sleeper beam is reinforced in four vertical rows ^{with 24} high-strength wires arranged symmetrically in two rows relative to the vertical axis of the cross trapezoidal cross section of the sleeper; the lower rows of wires at a distance δ from the end surfaces of the sleeper are fixed with rigid elements, the value of the parameter δ varies in the range from 120 to 250 mm.

The design of the inventive sleeper is proposed, which includes the following distinctive features:

1) Reinforced concrete universal sleeper, including a bar with a trapezoidal cross-section of variable length with upper surfaces for accommodating rail fastening parts, an anchor with shanks in the lower part of the anchor located in the sleeper, directed at an angle to the vertical axis in the range from 15 to 75 ° having an increase in cross-section at the end sections, with the geometry of all elements of the lower part of the anchor, which is a set of transition curves of large radius, and the geometry of the jumper corresponds to the geometry of the arch-type structure. Thus, the new design of the anchor does not have areas of conjugation of adjacent elements with small radii, which eliminates the stress concentration in these areas in the sleeper material in operation.

The results of the studies of the stress-strain state of a sleeper with a new design anchor located in the area of the under-rail base of the sleeper indicate a significant influence of the angle of deviation of the anchor shanks from the vertical axis on the stress-strain state of the sleeper. At angles of deviation of the anchor shanks from the vertical axis of more than 75° or less than 15°, the radii of conjugation of the shanks with the anchor bridge connecting the anchor heads are significantly reduced, which leads to the formation of zones with high intensity stress concentration in these areas of the sleeper. Repetitive-variable loads that act on the anchor and the area of the under-rail base of the sleeper during operation lead to the formation of stress concentration zones in the contact zones of the sleeper material with the anchor at the points of junction of the shanks with the anchor bridge. Moreover, as studies have shown, the concentration and intensity of stresses in the sleeper material are the higher, the smaller the radii of conjugation of the anchor shanks with the jumper. Therefore, the use of an anchor of a new design in a sleeper excludes in practice the formation in the sleeper material of areas with a concentration and intensity of stresses of a high level close to the values of the strength characteristics of the sleeper material, and, as a result, the formation of conditions for the initiation and development of crack-like defects.

Thus, on the basis of the conducted studies, it has been established that it is this range of deviation of the liner from the vertical axis that is the most effective for achieving the claimed technical result - increasing the durability, crack resistance and reliability of the sleeper.

2) The sleeper beam is reinforced in four vertical rows with high-strength wires arranged symmetrically in two rows relative to the vertical axis of the transverse trapezoidal section. The reinforcement of the beam is made in the form of 24 high-strength wires.

The conducted studies have shown that uniform reinforcement with the same number of wires in 4 rows in the horizontal plane and 6 rows in the vertical plane provides a uniform reinforcement of the sleeper material over the sleeper cross section with elements of higher rigidity - high-strength wires. This arrangement of reinforcing elements provides an increase not only in the longitudinal but also in the transverse stiffness of the sleeper, which is an important factor in terms of the impact on the sleeper not only of vertical forces due to the interaction of the rolling stock wheel with the rail in the vertical plane, but also of the horizontal forces implemented by the interaction of the wheel flange. with a rail head, despite the fact that the magnitude of the lateral forces can reach 40% of the magnitude of the vertical force. Also, this reinforcement scheme helps to increase the strength of the sleeper under the action of a shear force from the side of the rail when the rolling stock implements traction or braking modes, which contributes to the formation of significant loads, including on the anchor, and when implementing the proposed reinforcement scheme, the local tension of the sleeper material redistributed over the cross section of the sleeper with reinforcing wires.

The dimensions of the sleeper at the end have, respectively, the nominal dimensions of the trapezoidal section along the height H1, along the width of the upper and lower bases L1 and L2, and the middle part of the trapezoidal section has nominal dimensions, respectively, H2, L3 and L4, and in the under-rail section, the nominal dimensions of the sleeper are, respectively, H3, L5 and L6 mm. The geometric dimensions H1…H3 and L1…L6 are determined for each sleeper, taking into account the scope of its application. For example, in the manufacture of sleepers for use on a network of main railway lines, including high-speed, public and non-public railway lines, access rail tracks of industrial enterprises, rail tracks in tunnels, the geometric dimensions of the sleepers are: H1 = 145 ... 155 mm, H2 = 142 …150 mm, Н3=226…235 mm, L1=222…226 mm, L2=290…310 mm, L3=180…185 mm, L4=243…255 mm, L5=167…173 mm, L6=L2. The geometric dimensions of sleepers for use in urban agglomerations are determined taking into account axial loads, the type of rolling stock used, and the technical characteristics of the rails.

To equalize the deformation processes of all reinforcement elements in rows in height, the lower rows at a distance δ from the end surfaces of the sleepers are fixed with rigid elements. During operation, these fastenings make the end sections of these rows of reinforcement underloaded, which, in combination with the use of an anchor of a new design, eliminates the formation of tensile stresses in concrete in these zones, and as a result, eliminates the formation of conditions for cracking. The value of the parameter δ varies in the range from 120 to 250 mm. As a result of the research, it was found that with a size of δ<120 mm, the necessary unloading of the end sections of the fixed wires is not observed when the sleeper is loaded in operation and, as a result, the required condition is not met to exclude the formation of tensile stresses in concrete in the end sections of the sleeper. In the case of δ>250 mm, on the contrary, the fastenings are located so far from the ends of the sleeper that this leads to a significant unloading of the end sections of the fixed wires with an increase in the load in the middle part of these wires in operation, as well as an increased loading of all other rows of wires, which negatively affects stress-strain state of the sleeper as a whole. Thus, as a result of the research, it was found that the rational range for the parameter δ is the range from 120 to 250 mm.

Brief description of the drawings

The proposed invention is illustrated by Figures, which depict the geometry of the proposed technical solution and elements of the proposed design of the sleeper.

In FIG. 1 shows a general view of the sleeper from the side and from above. In FIG. 2 shows a view of the sleeper from the end part, the view is indicated by the letter A in Fig. 1, and in Fig. 3 shows a cross section of a sleeper along the B-B section shown in FIG. 1. In FIG. 4 shows the design of fastening the lower rows of high-strength wire at a distance δ from the end surfaces of the sleepers.

Implementation of the invention

In FIG. 1 pos. 1 shows the location of the anchor of a new design with shanks, in the lower part of the anchor, located in the sleeper, directed at an angle to the vertical axis in the range from 15 to 75 °, having an increase in cross-section at the end sections, with the geometry of all elements of the lower part of the anchor, which is a combination transition curves of large radius, and the geometry of the lintel corresponds to the geometry of the arch type structure. Also in FIG. 1 shows the placement of the fastenings of the lower rows of high-strength wire pos. 2 at a distance δ from the end part of the sleeper. In FIG. 2 shows the placement of four rows of high-strength wire over the sleeper cross section. In FIG. 3 shows the fastening of the lower rows of high-strength wire pos. 2. In FIG. 4 shows the geometry and design of the fastenings of the lower rows of high-strength wire. Wires, fig. 3 are fixed in pairs with special fastenings pos. 2, excluding any movement of the end sections of these wires during operation, which reduces the level of forces transmitted to the end sections of the wire when the sleeper is deformed in operation.

Universal reinforced concrete sleeper, including a beam with a trapezoidal cross-section variable along the length. Anchor 1 is rigidly placed in the sleeper. Each anchor head 1 protruding above the surface of the under-rail base of the sleeper has two brackets spaced along the rail. The lower part of the anchor, located in the sleeper, includes elements directed at an angle to the vertical axis in the range from 15 to 75°, having an increase in the cross section at the end sections. The geometry of all elements of the lower part of the anchor is a set of transition curves of large radius, and the geometry of the lintel corresponds to the geometry of the arch-type structure.

The dimensions of the sleeper have, respectively, the nominal dimensions of the trapezoidal section along the height H1, along the width of the upper and lower bases L1 and L2 mm, and the middle part of the trapezoidal section has the nominal dimensions, respectively, H2, L3 and L4, and in the under-rail section, the nominal dimensions of the sleeper are, respectively, H3, L5 and L6.

The sleeper beam is reinforced with high-strength wires in four vertical rows, arranged symmetrically in two rows relative to the vertical axis of the cross trapezoidal cross section of the sleeper. The reinforcement of the beam is made in the form of 24 high-strength wires. Uniform reinforcement with the same number of wires in 4 rows in the horizontal plane and 6 rows in the vertical plane instead of reinforcement in rows of 5 and 3 wires, implemented in the prototype, provides a uniform cross-section of the sleeper reinforcement over the cross-section of the sleeper material with elements of higher rigidity and, accordingly, leads to an increase in reliability , crack resistance and durability of the sleeper. The results of studies confirming the increase in the final service life are shown in Table 1.

To equalize the deformation processes of all reinforcement elements in height, the lower rows of high-strength wire at a distance δ from the end surfaces of the sleeper are fixed with special elements (Fig. 1, pos. 2), which can be made in the form of brackets. During operation, these fastenings make the end sections of these rows of reinforcement underloaded, which eliminates the formation of tensile stresses in concrete in these zones, and as a result, eliminates the formation of conditions for the formation of cracks. Thus, fixing the lower rows of reinforcing wires leads to a redistribution of stresses, both in the cross section and in the direction of the longitudinal axis, at the end sections of the sleeper in operation, which reduces the stress level in concrete in these areas, eliminates the formation of cracks in the end sections of the sleepers in operation. , increases the service life of the sleeper.

The implementation of the invention of the sleeper by fixing the two lower rows of reinforcement of the sleeper is illustrated by a specific example given in table 1.

Sources of information taken into account when compiling the description of the invention:

1. Utility model RU(11) 93812 (13) U1, 05/10/2010.

Claims (4)

Universal reinforced concrete sleeper, including a beam with a trapezoidal cross-section of variable length with upper surfaces for placing anchor rail fastening parts, characterized in that: in the area of the under-rail base of the sleeper there is an anchor with shanks located in the lower part of the anchor, located in the sleeper, directed at an angle to the vertical axis in the range from 15 to 75° and having an increase in cross-section at the end sections, with the geometry of all elements of the lower part of the anchor, which is a set of transition curves of large radius, and the geometry of the anchor lintel corresponds to the geometry of the arch-type structure; the sleeper beam is reinforced in 4 rows in the horizontal plane and 6 rows in the vertical plane with high-strength wires arranged symmetrically in two rows relative to the vertical axis of the transverse trapezoidal section of the sleeper; the lower rows of wires at a distance δ from the end surfaces of the sleepers are fixed with rigid elements, the value of the parameter δ varies in the range from 120 to 250 mm.

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