RU2104360C1 - Method for restoring designed stressed state of rail link in jointless rail track - Google Patents

Abstract

FIELD: railway track construction. SUBSTANCE: this relates to routine maintenance of jointless railway track. According to method, detected is section of rail link with deviations of its stressed state from designed values at given temperature of rail. Determined in this section are zones with stresses higher or lower than designed values, rail link is freed from connection with base within length of zone where actual stresses are higher than designed values. Eliminated is bending of rail link within aforesaid zone and restored are connections of rails with base. Released are connections of rail link with base within zone where actual stresses are lower than designed values. Created is extent of bending within zone where actual stresses are higher than designed values, and secured are earlier released connections. EFFECT: high efficiency. 5 dwg

Description

 The invention relates to railway transport and can be used for the current maintenance and repair of jointless track structure.

 There is a method of restoring the calculated stress state of the rail whip of the welded jointless path, which consists in identifying a portion of the rail whip of the welded jointless path with a deviation of the actual stresses from the calculated values, identifying more and less calculated values in this stretch of the zone, releasing the rail whip of this stretch from communication with the base, bend the rail lash at the beginning of the section where the actual stresses are less than the calculated values, move the bend arrow to the end of the section where the actual stresses of more than calculated values, increase the bending arrow in the process of its movement in the area where the actual stresses are less than the calculated values, and reduce the bending arrow in the process of its movement in the area where the actual stresses of more than calculated values are proportional to the actual deviation of the stresses from the calculated values, and fix on the rail base previously freed from ties with the base section of the rail lash [1].

 This technical solution was taken by the author as a prototype.

 The disadvantage of this method of restoring the calculated stress state of the rail of the rail of the welded jointless track is the large labor required to relieve the ties with the base of the section of the rail whip and the subsequent restoration of these connections.

 The aim of the invention is to increase efficiency by reducing labor costs. This goal is achieved by the fact that in the known method weaken the ties of the rail lash with the base throughout the section where the actual stresses are less than the calculated values, bend the section of the rail lash, where the actual stresses are greater than the calculated values and fix previously weakened ties.

 A comparative analysis of the claimed technical solution with the prototype shows that the claimed method differs from the known one in that the connections in the section of the rail lash, where the actual stresses are less than the calculated values, are weakened, bending is created throughout the section of the rail lash, where the actual stresses are greater than the calculated values, and fix previously weakened connections. Thus, the claimed method meets the criterion of "novelty."

 Comparison of the claimed method with other technical solutions shows that the steps to create a bend arrow within the area of the rail lash, where the actual stresses are greater than the calculated values, to restore the calculated stress state of the rail lash, are not known. This allows us to conclude that the proposed technical solution meets the criterion of "inventive step".

 In FIG. 1 shows a diagram of stresses in a rail lash arising during its operation; in FIG. 2 - places of weakening and removal of bonds within the lash; in FIG. 3 - place to create a bend of the rail lash section; in FIG. 4 - restoration of the calculated stress state within the area with weakened fasteners after creating a bend in an adjacent area; in FIG. 5 - restoration of the calculated stress state within the area with removed fastenings after the removal of the bend boom.

 The proposed method of restoring the calculated stress state of the rail whip of the weld jointless path is as follows.

The rail lash of the welded jointless track is fixed for continuous operation at a rail temperature, for example, equal to +20 ^o C (t _close = +20 ^o C).

The change in the stress state of the rail lash is controlled, for example, by moving the control sections 1 - 5 of the rail relative to the fixed frames. The distance between the benchmarks can be selected with a certain step, for example, 50 m. The uneven distribution of stresses across individual control sections should not exceed 10.0 MPa. During the next monitoring of the state of the rail lash, the movement of the control section 3 towards the section 2 was detected by a value of 10 mm (Δl = 10 mm) while maintaining the position of the remaining sections. The temperature of the rails at this time was, for example, +30 ^o C (t _p = + З0 ^o C).

The calculated stress value is determined by the formula:
σ _p = 2.5 • (t _closed - t _p ) = 2.5 • (-10) = - 25 MPa
Due to the fact that the distance between the control sections 2 and 3 decreased by Δl = -10 mm, and between the control sections 3 and 4 increased by Δl = +10 mm, then, therefore, the fixing temperature of the rail lash in these areas also changed at which stresses in rails will be equal to zero:
t _of = t _closed ± Δt,
Where
Δt is the value of the deviation from the fixing temperature of the section of the rail lash, ^o C.

где Δl - измеренное фактическое удлинение (с "+") или укорочение (с "-") плети, мм;
l - расстояние между контрольными сечениями (реперами), м.

where Δl is the measured actual elongation (s "+") or shortening (s "-") of the whip, mm;
l is the distance between the control sections (benchmarks), m

Температура закрепления участка рельсовой плети между контрольными сечениями 2 и 3 станет равна
t $\genfrac{}{}{0ex}{}{\text{2-3}}{\text{из}}$ = t_закр- Δt = 20^°- 17^°= 3^°C,
а фактическая средняя величина сжимающих напряжений между контрольными сечениями 2-3 будет равна:

Температура закрепления участка рельсовой плети между контрольными сечениями 3 и 4 станет равна:
t $\genfrac{}{}{0ex}{}{\text{3-4}}{\text{из}}$ = t_закр+ Δt = 20^°+ 17^°= +37^°C,
а фактическая средняя величина напряжений между контрольными сечениями 3-4 будет равна:

т.е. на этом участке в рельсе будут растягивающие напряжения.

The temperature of fixing the section of the rail lash between the control sections 2 and 3 will be equal to
t $\genfrac{}{}{0ex}{}{\text{2-3}}{\text{of}}$ = t _closed - Δt = 20 ^° - 17 ^° = 3 ^° C,
and the actual average value of compressive stresses between the control sections 2-3 will be equal to:

The fixing temperature of the section of the rail lash between the control sections 3 and 4 will be equal to:
t $\genfrac{}{}{0ex}{}{\text{3-4}}{\text{of}}$ = t _close + Δt = 20 ^° + 17 ^° = +37 ^° C,
and the actual average value of stresses between the control sections 3-4 will be equal to:

those. there will be tensile stresses in this section of the rail.

The actual stress value between the control sections 2 and 3 will be less than the calculated values (σ _p = -25 MPa, and σ _2-3 = -67.5 MPa), and the actual value of the stress between the control sections 3 and 4 will be more than the calculated values (σ _p = -25 MPa, and σ _3-4 = +17.5 MPa).

 After the control section of the rail lash section is identified by moving with actual stresses different from the calculated values, and two zones with voltages less than and greater than the calculated values are determined in this section, the rails with the base between the control sections 2 and 3 are loosened and released from the base rails between the control sections 3 and 4, create a bend arrow between the control sections 3 and 4, thereby forcibly lengthening the distance between the control sections 3 and 4 (the arc is always pulled longer s of the chord) and therefore increasing the tensile stress that will lead to a return control section to the starting position. As soon as section 3 returns to its original position, the rails are fixed to the base between the control sections 2 and 3, the bend arrow is removed and the rails to the base between the control sections 3 and 4 are restored.

 On this, the work to restore the calculated stress state of the rail whip of the welded jointless track ends.

 The proposed method of restoring the calculated stress state of the rail of the rail of the welded jointless path will increase efficiency by reducing the labor required to free the rails from the links with the base and restore these connections.

Claims (1)

 The method of restoring the calculated stress state of the rail whip of the welded jointless path, which consists in identifying a portion of the rail whip with deviations of its stress state from the calculated values for the given temperature of the rails, determining more and less than the calculated values in this section of the zone with voltages, freeing the rail whip from the connections with a base throughout the zone where the actual stresses are greater than the calculated values, eliminate the bending arrow of the rail lash within this zone and then restore link the rail lash with the base, characterized in that before said release of the rail lash from the ties with the base, its ties with the base are weakened over the zone where the actual stresses are less than the calculated values, after said release of the rail lash from the ties with the base, an arrow of bending of the rail lash in within the zone where the actual stresses are greater than the calculated values, and then fix the aforementioned weakened ties of the rail lash with the base and eliminate the bending arrow of the rail hildren.

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