CA2598637A1 - Railroad tie - Google Patents

Abstract

The sleeper (8) has a rigid concrete block (9) with a lower surface, and an upper face to receive a longitudinal rail (4), where the block has a weight ranging between 400 and 450 kilograms. A shoe (20) receives the rigid block, and is formed of a rigid shell comprising a peripheral edge (50) bordering a base of the shell. A resilient tie plate (22) is arranged between the lower surface of the block and the base of the shoe. The tie plate has a dynamic stiffness ranging from 6-8 kilo-newtons per millimeter.

Description

Railroad crossing The present invention relates to a railway sleeper, of the type comprising:
a rigid block having a lower face and an upper face intended to receive at least one longitudinal rail, - a liner for receiving the rigid block and formed of a hull gide having a bottom and a peripheral rim bordering this bottom, a resilient sole disposed between the underside of the rigid block and the bottom of the shoe.
Such sleepers are frequently used for laying of a railroad without ballast, for example in or on a work such as a tun-nel or a viaduct, offering as a support to the sleepers a raft or a slab.
EP-A-0 919 666 describes a cross-member of this type. The rigid bootie is embedded in a concrete slab, with which it forms a rigid assembly.
Each rail is generally supported by a resilient support element placed between each rail and the rigid block. Resilient support elements form thus a first elastic stage. They can be mounted at the time of installation of the way, or previously, for example at the time of the assembly of the pours.
The resilient sole disposed between the block and the rigid bootie forms as for it a second elastic floor.
The vibrations generated by the rails during the passage of trains are essen-normally damped at the level of the first and second elastic stages.
However, the attenuation of mechanical vibrations at the passage of train of this system of lane as it is known to date, is not fully tisfaisante. Indeed, the cutoff frequency and the insertion gain are more important than those, for example, of a track system on floating slabs.
The aim of the invention is to improve the attenuation performances of vibrations of the aforesaid cross-member, particularly in a frequency range than 250 Hz, which is considered as being capable of generating surrounding buildings, while limiting fatigue and stress suffered by the track system.

2 For this purpose, the subject of the invention is a cross-member of the aforementioned type, characterized in that the resilient sole has a dynamic stiffness k2 included enter 6kN / mm and 10kN / mm, preferably between 6kN / mm and 8kN / mm.
According to other features of the invention:
the resilient sole comprises a substantially flat upper face and a substantially flat bottom face;
the block comprises four peripheral faces which connect the face superior to the lower face, the crossbar comprising segments resilient arranged between each peripheral face of the block and the peripheral edge of the slipper;
the resilient segments comprise at least two segments longitudinal members whose dynamic stiffness is between 20kN / mm and 25kN / mm, and at least two transverse resilient segments whose stiffness dy-Namique is between 15kN / mm and 18kN / mm;
said crossmember comprises, on the upper face of the rigid block, a resilient support element whose dynamic stiffness is between 120kN / mm and 300kN / mm, preferably between 200kN / mm and 300kN / mm, the support element resilient being provided to receive the rail in support;
- The cross comprises a single block and a single boot;
the block has a mass of between 350 kg and 450 kg, preferably between 400kg and 450kg;
- the cross comprises two blocks, two slippers respectively as-companies and a transverse spacer connecting the two blocks; and each block has a mass of between 100 kg and 150 kg, preferably between 130kg and 150kg.
The invention also relates to a section of railroad track characterized in that it comprises a cross member as described above and at least one rail in support on the cross.
The invention will be better understood on reading the description which will follow, given as an example, and made with reference to the drawings, on which :
FIG. 1 is a diagrammatic cross-sectional view of a section section of a railway line according to a first embodiment;

3 FIG. 2 is a more detailed diagrammatic view in cross-section;
dirty of the crossbar of Figure 1;
FIG. 3 is a diagrammatic view in longitudinal section of the work pours figures 1 and 2;
FIG. 4 is a diagram modeling the section of railway of the gure1;
FIG. 5 is a graph illustrating the acoustic performances a cross member according to the invention; and FIG. 6 is a view similar to FIG. 1 of a section of railway track according to a second embodiment.
A section of railway 2 according to a first embodiment of the invention is illustrated schematically in FIG. 1. The section 2 comprises two longitudinal rails 4 fixed on a cross-member 8. The cross-member 8 comprises a single rigid block of concrete 9 and two resilient support elements 10 arranged in-be each rail 4 and block 9.
By convention, the longitudinal rails 4 define a reference of longitudinality.
The resilient support members 10 have a substantially parallel shape.
lépipédique. In the example shown in Figure 1, their width is sensibly equal to the width of the base of a rail 4, and their length is substantially equal to the width of the block 9.
The resilient support elements 10 are housed in a recess 12 respective block 9. The profile of each recess 12, in section cross, is substantially rectangular. The width and length of each recess are, in the example illustrated in FIG. 1, substantially equal to the width and the length of a resilient support member 10, respectively.
The resilient support elements 10 are for example glued to the cross member 8.
Each rail 4 is attached to the block 9 by means of rail fasteners (no represented) which prevent any transverse displacement of the rail relative to at block 9 and secure the rail 4 with the block 9 and with each support element resi-bind 10.

4 In all of the following, given the frequency range considered (less than or equal to 250 Hz), any dynamic stiffness is considered as constant and substantially equal to 130% of the static stiffness.
The resilient support elements 10 form a first elastic floor 14 of dynamic vertical stiffness k1 as modeled in FIG.
effect, each rail 4 is modeled as being suspended on a first end.
té of a spring 16 of dynamic stiffness k1. The second end of the spring 16 is linked to block 9.
Each resilient support element 10 has a dynamic stiffness k1 com-between 120 kN / mm and 300 kN / mm, preferably between 200 kN / mm and 300kN / mm. The material used for each resilient support member 10 is example of rubber, polyurethane or any other resilient material.
The crossbar 8 of FIG. 1, illustrated in detail in FIGS.
and 3, comprises a shoe 20 for receiving the block 9, a sole resilient 22 disposed in a substantially horizontal plane between the block 9 and the slipper 20, and four resilient segments 24, 26 disposed in a plane substantially verti-call between block 9 and shoe 20.
Block 9 has a substantially parallelepipedal shape and comprises essentially an upper face 32, a substantially flat lower face serving as support, and four peripheral faces 36, 38 connecting the face greater than 32 at the lower face 34 via respectively a rounded 44 and a bevel 46. The peripheral faces 36, 38 comprise two peripheral faces longitudinal 36 and two transverse peripheral faces 38.
The peripheral faces 36, 38 each comprise a lower portion substantially planar surface 36A, 38A, a substantially planar upper portion 36B, 38B, and a substantially flat intermediate portion 36C, 38C connecting each lower portion 36A, 38A at its respective upper portion 36B, 38B. The parts longitudinal upper 36B and transverse upper parts 38B
converge each other upwards. The longitudinal lower parts and the lower transverse portions 38A converge mutually towards the low.
The longitudinal intermediate portions 36C and the intermediate portions trans-38C converge mutually downwardly at an angle with respect to vertical plane greater than each respective lower part 36A, 38A.
Block 9 is chosen with a particularly large mass. Indeed-fet, its mass is between 350kg and 450kg, preferably between 400kg and

5 450kg. The increase in the mass of the block 9 is conventionally obtained by ad-joining of metallic elements in the concrete.
The liner 20 is formed of a substantially rigid shell. The shoe its 20 essentially comprises a bottom 48 and a continuous peripheral rim along the bottom 48.
The bottom 48 has an upper face 52 substantially flat and rec-tangulaire.
The peripheral rim 50 of the liner 20 comprises four panels 54, 56. The four panels 54, 56 comprise two longitudinal panels 54 associated respectively with the longitudinal faces 36 of the block 9 and two panels transversals 56 associated respectively with the transverse faces 38. Each panel 54, 56 comprises a respective inner face 62, 64. Each face internal 62, 64 comprises a substantially parallelepipedic housing 66, 68 for receive each of the resilient segments 24, 26.
The housings 66, 68 are substantially parallel to the lower parts respectively 36A, 38A of the peripheral faces 36, 38 of the block 9. Each housing 66, 68 has a rectangular periphery defined by a shoulder peri-continuous pheric 66A, 68A. Each housing 66, 68 also has substantially the same height and substantially the same length as the lower part 36A, 38A with which he is associated.
Each inner face 62, 64 comprises an upper portion 62A, 64A
flat and whose inclination relative to the vertical is substantially equal or su-greater than the inclination of the respective intermediate portions 36C, 38C of the sides peripherals 36, 38 of block 9. The upper portions 62A, 64A have the same height as the respective intermediate parts 36C, 38C of block 9.
The upper portions 62A, 64A of the inner faces 62, 64 of the 54, 56 are connected to a continuous upper edge 70 of the flange 50.
edge In the example illustrated in FIGS. 2 and 3, upper 70 shows two fingers per-

6 making it possible to fix a continuous seal 72. The seal 72 is for example in natural or synthetic rubber. It creates a seal between block 9 and the slipper 20 without affecting the movement of the block 9 in the shoe 20. It is also possible to make the seal 72 by casting a material such silicone or polyurethane, in the form of a continuous bead.
The stiffness of the boot 20 is reinforced by ribs 74 in relief on the outside of panels 54, 56 and, in part, under background 48.
They are for example material with the shoe 20. These ribs 74 may present any appropriate form and any appropriate rap-port slipper 20, as known in the state of the art, including by EP-AO 919 666. They have, in the example illustrated in FIGS. 2 and 3, of the notches 76 for anchoring the boot 20 on an armature. Ribs 74 are, when laying the track, drowned at least partially in the concrete.
They thus ensure the fastening of the shoe 20 with the filling concrete.

wise.
In the example illustrated in FIGS. 2 and 3, the liner 20 is made in one piece, by molding. In a manner not illustrated, the shoe 20 is made by assembly of several partial shells as is known in the state of the technical (eg EP-A-0 919 666). In the case of an 8 piece monobloc according to the first embodiment of the invention, it may for example this is two half-hulls end and a central hull connecting the two half end shells.
The shoe 20 is for example made of thermoplastic material molded or resin concrete.
The resilient soleplate 22 has a substantially parallelepipedal shape and substantially flat upper and lower faces to minimize mechanical stresses experienced by the resilient soleplate 22 and to avoid problems fatigue. Its length and width are substantially equal respectively at the length and width of the lower face 34 of the block 9.
Its thickness is between 10mm and 20mm, preferably between 16mm and 20mm. The resilient sole 22 thus remains in an elastic domain;
which corresponds substantially to a lower maximum deformation rate or

7 equal to 40%. The rate of deformation is the rate of change of thickness ia resilient sole 22 between a free state and a state under load.
The resilient soleplate 22 forms a second resilient stage 78 of sufficient strength.
vertical dynamic range as modeled in Figure 4. In fact, the rigid block 9 is modeled as being in suspension on the first ends of two springs 80 of dynamic stiffness k2. The second ends of the springs 80 are related to the shoe 20.
The resilient soleplate 22 according to the invention has a dynamic stiffness less than the dynamic stiffness of the devices conventionally used. In effect, the dynamic stiffness k2 is between 6kN / mm and 10kN / mm, preferably between be 6kN / mm and 8kN / mm.
The resilient soleplate 22 is for example made of an elastic material cellular tomere.
In a preferred embodiment, the resilient soleplate 22 has a vertical dynamic range substantially uniform throughout its entire area.
In another embodiment, the resilient soleplate 22 has, in a central zone of block 9, a vertical dynamic stiffness k3 lower or equal to k2. The central zone comprises the middle of block 9 and extends transversely of middle of the block 9 towards the ends on substantially half of the surface of block 9. Indeed, this central area being less stressed, it is possible to use it a more elastic material and therefore less expensive.
The resilient soleplate 22 can rest freely on the bottom 48 of the slipper 20. It can thus easily be removed from the slipper 20.
Advantageously, the crossbar 8 also includes a shim of thickness 82 substantially incompressible, as illustrated in FIGS.
and 3.
The shim 82 has a substantially parallelepiped shape.
Its length and width are substantially equal to the length and the width of the upper face 52 of the bottom 48 of the liner 20. Its thickness is lower or equal to 10 mm, preferably between 2 mm and 4 mm.
The shim 82 rests freely on the bottom 48 of the liner 20.
Thus, it can be easily removed from the shoe 20, or added to the Chaussées its 20, to adjust the leveling of the track.

8 Advantageously, the resilient sole 22 rests freely on the shim 82.
The surface of the shim 82 has a sufficiently high roughness bearing to prevent the sliding of the resilient soleplate 22 into the slipper 20.
The roughness is for example obtained by means of streaks, diamond tips or pimples.
Each resilient segment 24, 26 has an outer face 24A, 26A, an inner face 24B, 26B and four peripheral faces.
The external faces 24A, 26A and internal 24B, 26B substantially have the same dimensions and have a substantially rectangular outline.
The external faces 24A, 26A and internal 24B, 26B have a length and a width substantially equal to the length and the width respectively of the respective housings 66, 68 of the peripheral rim 50 of the liner 20.
The resilient segments 24, 26 are disposed in the housings 66, 68. They are for example maintained thanks to the friction between fa-these devices resilient segments 24, 26 and the peripheral shoulder 66A, 68A of each housing 66, 68. The resilient segments 24, 26 can also if be removed easily.
The restraint of each resilient segment 24, 26 can also be secured by mutual snapping. For example, dwellings 66, 68 include grooves and the resilient segments 24, 26 comprise splines plementary.
The resilient segments 24, 26 have a thickness greater than the founders 66, 68 so as to protrude from the shoulders 66A, 68A.
The internal faces 24B, 26B are in simple support against the internal parts respective bottoms 36A, 38A of the peripheral faces 36, 38 of the rigid block

9.
As illustrated in FIGS. 2 and 3, the internal faces 24B, 26B are of grooves increasing their elasticity.
The resilient segments 24, 26 have a dynamic stiffness included between be 12kN / mm and 25kN / mm. They are for example made of rubber, polyurethane thanne or any other resilient material.

The longitudinal segments 24 corresponding to the peripheral faces longitudinal 36 are subject to greater efforts than the segments transverse 26 corresponding to the transverse peripheral faces 38. Also, the longitudinal segments 24 can be advantageously chosen with a greater dynamic stiffness than transverse segments 26. Thus, the longitudinal segments 24 have, for example, a dynamic stiffness comprised between 20kN / mm and 25kN / mm, while the transverse segments 26 have a reasonable dynamic range between 15kN / mm and 18kN / mm.
Under normal operating conditions, the resilient segments 24, 26 hold the block 9 away from the inner faces 62, 64 of the shoe 20.
The resilient segments 24, 26 thus allow a horizontal damping This horizontal damping is decoupled from the damping.
vertical obtained thanks to the resilient support elements 10 and the sole resilient 22.
It will be noted that the number of resilient segments is not limiting. The 8 may for example comprise, on each side of block 8, two segments transversal elements 34 next to each other.
FIG. 5 illustrates the acoustic performance of a cross member according to the invention and a known crossbar. Figure 5 shows a gain insertion in frequency function. The insertion gain is here the ratio expressed in dB
enter the value of a metric quantity (speed, acceleration, force, etc.) obtained with the introduction of a resilient sole and that obtained without it (see NF ISO
14837-1: 2005). In the example under consideration, this is the force exerted on the 20. A reduction in the value of the metric quantity shall be expressed by a negative sign of the insertion gain.
In addition, the cutoff frequency is the frequency from which overall, a decrease in the insertion gain is observed.
k1dyn is the dynamic stiffness of the resilient support elements 10, k2dyn is the dynamic stiffness of the resilient soleplate 22, M is the mass of the block 9.
The curve showing the insertion gain as a function of frequency for k2dyn = 21.3 MN / m, M = 200 kg, k1 dyn = 150 MN / m constitutes a reference curve.
SI code illustrating the performance of the known device. A second curve illustrated the performance of a cross member according to the invention of which k2dyn = 8MN / m, M = 400 kg and k1 dyn = 270 MN / m.
Between 0 and 10 Hz, vibration attenuation performance is substantially the same. Between 10 and 25 Hz, the insertion gain is higher of 5 dB relative to the SI curve. Between 25 Hz and 250 Hz, the gain insertion is several dB lower than the S1 curve.
In addition, the cutoff frequency is lower than the curve S1 (20Hz instead of 32Hz).
Thus, between 25 Hz and 250 Hz, the performance of a cross member according to

The invention are substantially better.
In a second embodiment illustrated in FIG.
108 comprises two rigid blocks 109 connected by a spacer 184. In the sure where the biblock cross 108 has great similarities with the crossing monobloc 8, we find, in Figure 6, the same references as in Figures 1 at 4, however incremented by 100.
The length of the slippers 120 is adapted to receive the blocks 109. The same is true for the transverse segments 126 and the 122. Figures 2 and 3, which illustrate a monobloc cross member 8, are equal-a perfect illustration of a crossing 108.
The main difference between the monobloc crossbar 8 and the crossbar block 108 is the presence of a spacer 184 penetrating the two blocks 109.
The decrease of the dynamic stiffness K2 of the resilient soles 122 and / or increasing the mass of the blocks 109 generate a bending moment significant longitudinal Also, the spacer 184 has a shape adapted to obtain a strong tie. This is for example a shape square or cylinder. The spacer 184 a for example also a section between 800mm2 and 1500mm2 and a thickness between 6mm and 10mm. It is for example made of steel according to EN 13230-3.
Each block 109 has a mass of between 100 kg and 150 kg, preferably between 130 kg and 150 kg.

11 It will be noted that the monobloc cross member 8 supports particularly easily the additional mechanical stresses resulting from the invention.
It will be understood that with a cross member according to the invention, the reduction of the dynamic stiffness k2 of the resilient soleplate 22, 122 makes it possible to obtain meil-their vibration attenuation performance, in particular by lowering the frequent cutoff and lowering the insertion gain between 25Hz and 250HZ.
The increase in the mass of the block 9, 109 also makes it possible, for a dynamic stiffness k2 resilient sole 22, 122 given, to lower the frequent quence and thus improve the performance of the crossbar 8, 108 in the low frequencies. However, above a certain mass, the mechanical stresses experienced by the crossbar 8, 108 become too much important.
The increase of the dynamic stiffness k1 of the support elements resides 10, 110 lowers the insertion gain between 200Hz and 250Hz and moves the frequent resonance towards higher frequencies, the frequency of reso-nance being the frequency for which a rise in the gain of inser-tion.
The invention therefore makes it possible to approach performance vibration attenuation obtained with a floating slab whose frequency of cutoff is between 14Hz and 20Hz and whose insertion gain at -25dB is located at 63Hz.

Claims (10)

A railway crossing (8; 108) of the type comprising:
a rigid block (9; 109) having a lower face (34) and a face upper (32) for receiving at least one longitudinal rail (4; 104), a liner (20; 120) for receiving the rigid block (9; 109) and formed of a rigid shell having a bottom (48; 148) and a flange peripheral (50; 150) bordering this bottom (48; 148), a resilient sole (22; 122) disposed between the lower face (34) the rigid block (9; 109) and the bottom (48; 148) of the liner (20; 120), characterized in that the resilient sole (22; 122) has a stiffness Namique k2 between 6kN / mm and 10kN / mm, preferably between 6kN / mm and 8kN / mm. 2. Traverse (8; 108) according to claim 1, characterized in that the resilient sole (22; 122) has a substantially planar upper face and a substantially flat bottom face. 3. Traverse (8; 108) according to claim 1 or 2, characterized in that the block (9; 109) comprises four peripheral faces (36, 38) which connect the upper face (32) to the lower face (34), the cross member (8; 108) comprising resilient segments (24, 26; 124, 126) disposed between each face peripheral that (36, 38) of the block (9; 109) and the peripheral rim (50; 150) of the slipper (20; 120). 4. Traverse (8; 108) according to claim 3, characterized in that the resilient segments (24, 26; 124, 126) comprise at least two segments longitudinal resilients (24; 124) whose dynamic stiffness is included enter 20kN / mm and 25kN / mm, and at least two transverse resilient segments (26;
126) whose dynamic stiffness is between 15kN / mm and 18kN / mm. 5. Traverse (8; 108) according to any one of the preceding claims characterized in that it comprises, on the upper face (32) of the block rigid (9; 109), a resilient bearing element (10; 110) whose stiffness dynamic is between 120kN / mm and 300kN / mm, preferably between 200kN / mm and 300kN / mm, the resilient bearing member (10; 110) being adapted to receive the rail (4; 104) in support. 6. ~ Traverse (8) according to any one of the preceding claims, characterized in that the cross member (8) comprises a single block (9) and a unique slipper (20). 7. ~ Traverse (8) according to claim 6, characterized in that the block (9) has a mass of between 350 kg and 450 kg, preferably between 400 kg and 450kg. 8 ~ Traverse (108) according to any one of claims 1 to 5, ca characterized in that the cross member (108) comprises two blocks (109), two shoes respective associated sounds (120) and a transverse spacer (184) connecting the two blocks (109). 9. ~ Traverse (108) according to claim 8, characterized in that each block (109) has a mass of between 100kg and 150kg, preferably between 130kg and 150kg. 10. ~ Section of railroad tracks (2; 102), characterized in that it comprises a cross member (8; 108) according to any one of the preceding claims and at least one rail (4; 104) resting on the crossmember (8; 108).