Method for upgrading the wooden structure of No. 7 symmetrical three-way turnout to concrete structure

Abstract

The application discloses a kind of 7 number symmetry three open turnout wood changes concrete structure upgrading method, belong to turnout upgrading and reconstruction technical field.Adopt following anti-falling means: (1) adjustment point rail lower value;(2) cancel the rail brace of basic rail outside, and the length 320mm of elastic clip is used in switch section to press the inside of basic rail, and the elastic clip design elastic range is 7mm, and the pressure of buckling is not less than 11kN;(3) turnout is equipped with anti-derailing device;(4) middle frog toe heel end length 1400+2190mm, rear end frog toe heel end length 1550+2652mm;Vehicle straight direction passes through rear end two frogs, and guard rail cannot be separately set, so straight direction wheel flange groove straight section extends 150mm before theoretical point end to prevent the point end of opposite frog;(5) guard rail is manufactured using 43kg / m steel rail, and guard rail top surface is 12mm higher than basic rail top surface;Guard rail straight section wheel flange groove is 57mm, and opening section groove width is 85mm or 100mm.

Description

Technical Field

[0001] The present invention belongs to the technical field of turnout upgrading and reconstruction, and particularly relates to a method for upgrading a No. 7 symmetrical three-opening turnout from wood to concrete structure. Background Art

[0002] Of the national railway bureaus, only Wuhan and Taiyuan bureaus still have the 50-7 wooden sleeper three-way turnouts in use (drawing number: Special Line 8668). Due to the poor overall stability of the wooden sleeper structure and the spike-anchored fastener structure, the turnout assembly dimensions are difficult to stabilize, making maintenance work and difficulty extremely difficult, posing a safety hazard to train operation. Wuhan Bureau's original three-way turnouts, totaling seven sets, were all used under the hump of the Xiangyang North marshalling yard II. With the increasing freight volume, the turnouts at the station yard are gradually being upgraded from wooden to concrete structures and expanded to increase transportation capacity and safety. The original three-way turnouts no longer meet the requirements of the existing station yard. The existing wooden sleeper turnouts need to be converted to concrete sleepers, and the rail components, electrical switching structures, and other parts need to be redesigned. The fastener system needs to be strengthened, and anti-derailment devices need to be added to comprehensively improve the turnout performance level. Summary of the Invention

[0003] The embodiment of the present invention provides a method for upgrading the wooden structure of No. 7 symmetrical three-way turnout to concrete structure. The original wooden sleeper structure is upgraded to concrete sleepers; other structures are upgraded at the same time; the design requirements are: the full length, full length, rear length and main plane dimensions of the turnout are consistent with the existing turnout, maintaining the interchangeability and wide application of the turnout; the turnout allowable passing speed is: 30km / h; and an anti-derailment design is performed. The technical solution is as follows:

[0004] The embodiment of the present invention provides a method for upgrading the wooden structure of No. 7 symmetrical three-way turnout to concrete structure, which adopts one or more of the following anti-slip measures:

[0005] (1) Adjust the lowering value of the point rail: the tip of the point rail is lowered by 23mm; the 5 section is lowered by 12mm; the 15 section is lowered by 3mm, and the 40 section is lowered by 0mm; the working side of the straight point rail is vertical, and the working side of the lateral point rail adopts a 1:5 slope.

[0006] (2) The rail supports on the outside of the base rail are removed, and a 320mm long elastic clip is used to clamp the inside of the base rail in the switch section. The elastic clip is designed to have a spring range of 7mm and a clamping force of not less than 11kN. To meet the installation cavity space of the elastic clip, the point rail is raised by 6mm, forming a 30mm height difference between the base and point rails. On the switch sleepers No. 17-19, the height of the guide rails connected to the point rail is gradually lowered by pads, and the distance between each sleeper is reduced by 1.5mm, until the rail height difference on the switch sleeper No. 20 is reduced to 0.

[0007] (3) The turnout is equipped with an anti-derail device: The anti-derail device is 3100 mm long, with the starting point at 1596 mm in front of the tip of the switch rail, the length of the opening section is 150 mm, the length of the front buffer section is 1150 mm, and the length of the rear buffer section is 700 mm; the straight section wheel flange groove is 53 mm and is divided into two sections: the first section is parallel to the base rail from 296 mm in front of the tip of the switch rail to the 5 mm section of the switch rail; the second section is parallel to the closed curved switch rail from the 5 mm section of the switch rail to the 15 mm section of the switch rail; the upper surface of the active side of the anti-derail device is 22 mm higher than the top surface of the base rail; the non-active side is lowered, and its height is not higher than the upper surface of the working side of the anti-derail device; the lower surface of the working side of the anti-derail device starts to rise from 100 mm in front of the tip of the switch rail, and after the 5 mm section of the switch rail, the lower surface of the anti-derail device follows the lowering value of the switch rail and maintains a 7 mm gap with the top surface of the switch rail.

[0008] (4) The toe-heel length of the middle frog is 1400+2190mm, and the toe-heel length of the rear frog is 1550+2652mm. When the vehicle passes through the two rear frogs in a straight line, it is impossible to set up a guardrail separately. Therefore, the straight section of the straight wheel flange groove is extended 150mm before the theoretical tip to protect the tip of the opposite frog.

[0009] (5) The guardrail is made of 43kg / m steel rail, and the top surface of the guardrail is 12mm higher than the top surface of the basic rail; the wheel flange groove of the straight section of the guardrail is 57mm, and the groove width of the open section is 85mm or 100mm.

[0010] Among them, the parameters that have not been adjusted in the upgrade of the wood-to-concrete structure include: the total length of the turnout is 24150mm, the length before the turnout is a=11465mm, the length after the turnout is b=12685mm, the plane line type adopts a secant circular curve line type, and the cutting distance is 15.78mm; the tip of the point rail is a semi-tangent line type; the radius of the circular curve is 180m; it has eight sets of insulation, and the position remains unchanged; the impact angle of the lateral point rail tip is 1.35°, the impact angle of the middle switch guard rail is 1.33°, and the impact angle of the rear end switch guard rail is 1.55°.

[0011] The upgrade of the wood-to-concrete structure includes: no rail bottom or top slope is set in the turnout area, and slope pads are installed before and after the turnout; prestressed concrete long turnout sleepers are used under the iron pads; the sleeper spacing in the turnout area is arranged at 550-600mm, the sleeper spacing at the traction point is 650mm, and the maximum sleeper spacing at the insulating joint at the rear end of the switch is 445mm; the turnout sleepers are perpendicular to the turnout centerline, of which No. 35-49 are combined long turnout sleepers;

[0012] Among them, nylon casing is embedded in the switch sleeper and connected to the pad through switch sleeper bolts. The cross-section of the switch sleeper is an isosceles trapezoid, with a height of 220mm and upper and lower widths of 260mm and 300mm respectively. The main steel bars are 14 Φ7.0mm prestressed steel wires. Stirrups are provided at both ends of the switch sleeper, and spiral bars are provided on the outside of the casing.

[0013] Among them, the fastener system used in the wood-to-concrete structure upgrade is: the rails are fastened with separate Type I spring clip fasteners and T-bolts; the No. 11 gauge block is installed on the non-working side of the rail, and the No. 13 gauge block is installed on the working side, and 7-17 spare gauge blocks are provided for on-site adjustment to achieve a gauge adjustment range of -12—+8mm; a separate double-layer elastic structure is adopted, with a 5mm thick rubber pad under the rail and a 10mm thick rubber pad under the plate.

[0014] Specifically, rubber pads are used under the plate, oil-resistant rubber pads are used in the switch part, pressure-resistant rubber pads are used in the frog part, and thermoplastic polyester elastomer TPEE is used under the rail.

[0015] Among them, the pad system used in the wood-to-concrete structure upgrade is: a full-length connecting pad is set in the turnout guide curve part; and support clips and spring bars are added to the part from the heel end of the point rail to the glued rail joint.

[0016] Among them, the pointed rails used for the wood-to-concrete structure upgrade are: the basic rails are made of 50kg / m steel rails with a length of 7900mm; the straight and lateral pointed rails are both made of 50AT1 steel rails, the straight pointed rail is 5480mm long and the lateral pointed rail is 5038mm long, and the tips of the two pointed rails are at the same starting point; the basic rails and the straight pointed rails are closely fitted with curves, and top irons are set on the basic rails and lateral pointed rails after the starting point of the pointed rail head planing. The heel end of the pointed rail adopts a double-spacer iron type flexible joint structure, and the inner and outer rail supports of the rudder are set. The two pointed rails are switched by double-headed studs and steel sleeves, and two spacer irons are set behind the heel end of the pointed rail.

[0017] Among them, the traction points used in the wood-to-concrete structure upgrade are: one traction point is set for each pair of point rails, and there are two pull rods in total at the turnout. The travel at the tip of the point rail is 180mm, and the minimum wheel flange groove is 86mm; slotted joint irons and extended joint irons are used at the overlapping position of the two pull rods to achieve mutual displacement of the two pull rods.

[0018] This embodiment of the present invention provides a method for upgrading the wooden structure of a No. 7 symmetrical three-way turnout to concrete. The original wooden sleeper structure is upgraded to concrete sleepers; other structures are also upgraded simultaneously. The design requirements are: the turnout's overall length, overall length, rear length, and main plane dimensions are consistent with existing turnouts, maintaining their interchangeability and wide application; the turnout's allowable speed is 30 km / h; and an anti-derailment design is implemented. Five anti-derailment designs are used to prevent derailment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the plan layout of the No. 7 symmetrical three-way turnout;

[0020] Figure 2 It is the location diagram of the insulation;

[0021] Figure 3 It is a schematic diagram of the cross section of the switch tie;

[0022] Figure 4 It is a structural diagram of the fastener system;

[0023] Figure 5 It is a structural diagram of the combination of anti-derailment guardrail, spacer iron and turnout;

[0024] Figure 6 It is a structural diagram of the combination of stock rail and point rail;

[0025] Figure 7 It is the position distribution diagram of the support gusset plate, insulating gusset plate and spacer iron;

[0026] Figure 8 This is a diagram showing the usage status of the spacer iron;

[0027] Figure 9 It is a structural diagram of the traction point;

[0028] Figure 10 It is a schematic diagram of the 5-section reduction;

[0029] Figure 11 It is a schematic diagram of the lowering of section 15;

[0030] Figure 12 It is a schematic diagram of the lowering of section 40;

[0031] Figure 13 It is a structural schematic diagram of an anti-derailment device;

[0032] Figure 14 This is a diagram of frog placement;

[0033] Figure 15 Schematic diagram of the guardrail structure. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] The embodiment of the present invention provides a method for upgrading the wooden structure of the No. 7 symmetrical three-way turnout to a concrete structure. After the No. 6 symmetrical turnout with concrete sleepers replaced the wooden sleeper turnout, the number of derailment incidents at the No. 6 turnout under the hump increased. After investigation, the basic conclusions of the derailment accidents are as follows:

[0036] (1) The derailed switches were all located at the throat below the hump. The speed of the dismantled vehicles passing through this location was 20 km / h. Although it did not exceed the allowable speed of the switch, the vehicle passing speed at this location was the highest among all the switches in the station.

[0037] (2) All the derailed vehicles are empty. The dismantled and released vehicles are often a mixture of empty and loaded vehicles. The vehicles that initially derailed were all empty, causing other vehicles to derail.

[0038] (3) All turnouts use concrete sleepers, and rail supports are installed on both sides of the switch rails, which increases the lateral rigidity of the turnouts. The probability of derailment is relatively low when wooden sleepers are used.

[0039] (4) The location where the train climbs the track is consistent with the location where the train derails. Although the horizontal and vertical sections of the turnouts are different, the locations of the retarders are different, the maintenance and repair status are different, and the guardrail settings are different, the location where the train climbs the track in the turnout is at the tip of the point rail, and the location where the train derails is located behind the heel of the point rail. This shows that there is a regular pattern in the occurrence of derailment, which is related to the structure of the turnout itself. In view of the above characteristics, this embodiment adopts one or more of the following anti-derailment measures:

[0040] (1) According to the conclusion of previous derailment accident investigation, increasing the lowering value of the point rail will increase the risk of derailment; and considering that when passing through the three-way turnout sideways, the straight lateral point rails are jointly stressed, and the actual cross-sectional width is close to twice that of a single point rail, so this turnout moderately reduces the lowering of the point rail. Figure 10-12 , adjust the lowering value of the point rail: the tip of the point rail is lowered by 23mm; the 5 section is lowered by 12mm; the 15 section is lowered by 3mm, and the 40 section is lowered by 0mm; the working side of the straight point rail is vertical, and the working side of the lateral point rail adopts a 1:5 slope.

[0041] (2) In order to enhance the track elasticity, the rail supports on the outside of the base rail are removed, and a 320mm long elastic clip is used to clamp the inside of the base rail in the switch section. The elastic clip is designed to have a spring range of 7mm and a clamping force of not less than 11kN. To meet the installation cavity space of the elastic clip, the point rail is raised by 6mm, forming a 30mm height difference between the base and point rails. On the switch sleepers No. 17-19, the height of the guide rails connected to the point rails is gradually lowered by pads, and the distance between each sleeper is reduced by 1.5mm, until the rail height difference on the switch sleeper No. 20 is reduced to 0.

[0042] (3) Anti-derailment device for turnout: see Figure 13 The anti-derail device is 3100mm long, starting 1596mm in front of the point rail tip (extending 181mm beyond the front end of the stock rail). The opening section is 150mm long, the front buffer section is 1150mm long, and the rear buffer section is 700mm long. The straight section has a 53mm wheel flange groove and is divided into two sections: the first section runs parallel to the stock rail from 296mm in front of the point rail tip to the 5mm section of the point rail; the second section runs from the 5mm section of the point rail to the 15mm section of the point rail, parallel to the closed curved point rail. The upper surface of the active side of the anti-derail device is 22mm higher than the top surface of the stock rail; the inactive side is lowered for mounting bolts, insulators, and other connecting parts, and its height does not exceed the upper surface of the working side of the anti-derail device. The lower surface of the working side of the anti-derail device begins to rise 100mm in front of the point rail tip. After the 5mm section of the point rail, the lower surface of the anti-derail device follows the lowering of the point rail, maintaining a 7mm gap with the top surface of the point rail.

[0043] (4) See Figure 14 , the three-way turnout includes a middle frog, a left rear frog, and a right rear frog, a total of three different frogs, mainly because the curve extends into the rear frog range, and the two rear frogs cannot be used in common. Considering the installation and processing space and the arrangement of the turnout pillow when using the standard joint plate connection, the toe-to-heel length of the middle frog is 1400+2190mm, and the toe-to-heel length of the rear frog is 1550+2652mm; when the vehicle passes straight through the two rear frogs, guard rails cannot be set up alone, so the straight flangeway groove of the straight edge extends 150mm before the theoretical tip to prevent the tip of the opposite frog.

[0044] (5) See Figure 15 , the guard rail is made of 43kg / m steel rail, and the top surface of the guard rail is 12mm higher than the top surface of the basic rail; the flangeway groove of the guard rail is 57mm, and the opening section groove is 85mm or 100mm wide. After the guard rail wear is added with an adjusting piece, it can still meet the smooth passing of the vehicle.

[0045] Preferably, the above five means are all used to ensure the anti-falling effect. It has been verified that when all five means are used, no derailment has occurred in two years (since August 2020).

[0046] Among them, see Figure 1 , the parameters that are not adjusted in the upgrade of the wood-to-concrete structure include: the total length of the turnout is 24150mm, the length of the turnout front a=11465mm, and the length of the turnout rear b=12685mm, which is consistent with the original wood turnout. The planar line type adopts a tangent circle curve line type with a tangent distance of 15.78mm; the tip of the switch rail is a half tangent type; the radius of the circular curve is 180m. There are eight groups of insulation, and the positions remain unchanged; specifically, see Figure 2 , the turnout front, the turnout rear, the two sides of the stock, and the heel of the basic rail, a total of eight groups of insulation, including four groups of glued insulation and four groups of ordinary insulation. Four groups of insulation are set behind the heel of the straight and curved switch rail, and the insulation is located 1440mm behind the heel of the switch rail. Since 1440mm of short steel rail is used, 50m / kg steel rail factory glued insulation is used to increase the overall strength of the insulation position steel rail. The distance between the pillows on both sides of the insulation position is also limited, with a minimum pillow distance of 445mm. The lateral switch rail tip impact angle is 1.35°, the middle frog guard rail impact angle is 1.33°, and the rear frog guard rail impact angle is 1.55°. At a passing speed of 30km / h: the lateral switch rail tip impact angle is 1.35°, the kinetic energy loss is 0.50; the middle frog guard rail impact angle is 1.33°, the kinetic energy loss is 0.48; the rear frog guard rail impact angle is 1.55°, the kinetic energy loss is 0.66; all less than the comfort requirement of 0.8, meeting the use requirements of lateral passing speed of 30km.

[0047] Among them, the upgrade of wooden to concrete structure includes: no track bottom slope or track top slope is set in the switch area, and slope pads are set before and after the switch, and prestressed concrete long switch sleepers are used under the iron pads; the sleeper spacing in the switch area is arranged at 550-600mm, the sleeper spacing at the traction point is 650mm, and the maximum sleeper spacing at the insulating joint at the rear end of the switch is 445mm; the switch sleepers are perpendicular to the center line of the switch, of which No. 35-49 are combined long switch sleepers.

[0048] Among them, see Figure 3 Nylon sleeves are embedded in the switch sleepers and connected to the pads via bolts, significantly enhancing their integrity and stability compared to wooden sleepers. The switch sleepers have an isosceles trapezoidal cross-section, 220mm high, with upper and lower widths of 260mm and 300mm, respectively. The main reinforcement consists of 14 Φ7.0mm prestressed steel wires, stirrups are installed at both ends of the switch sleepers, and spiral reinforcement is provided around the sleeves. Electrical nuts are embedded at fixed intervals on the switch sleepers on both sides of the traction point for mounting the switch machine support frame. The embedded nuts are arranged symmetrically, allowing the switch machine to be installed on the left or right side of the turnout, depending on the situation.

[0049] Among them, the fastener system used in the wood to concrete structure upgrade is: Figure 4 The rails are fastened with split Type I spring clips and T-bolts. Gauge blocks #11 are installed on the non-working side of the rails, #13 on the working side, and 7-17 spare gauge blocks are provided for on-site adjustment, achieving a gauge adjustment range of -12 to +8 mm. A split, double-layer elastic structure is employed, with a 5 mm thick rubber pad under the rail and a 10 mm thick rubber pad under the plate. These provide primary elasticity, acting in tandem with the stiffness of the pad under the rail to adjust the vertical stiffness of the fastener system. This split elastic structure offers advantages such as convenient and flexible setup, reasonable cost, and ease of replacement.

[0050] Specifically, rubber pads are used under the plate, oil-resistant rubber pads are used in the switch part, pressure-resistant rubber pads are used in the frog part, and thermoplastic polyester elastomer TPEE is used under the rail.

[0051] The wood-to-concrete structure upgrade utilizes a pad system: A full-length connecting pad is installed in the turnout guide curve to enhance overall turnout stability, control the turnout standoff and track gauge, and prevent lateral pad shifting that could break the turnout tie bolts. Pads and spring bars are added from the point rail heel to the glued rail joint to enhance the turnout rail clamping stability.

[0052] Among them, see Figure 5 In order to increase the safety of the use and maintenance of turnout bolts, a cotter pin anti-slip structure is set for the anti-slip guardrail vertical bolts, the rut large pad vertical bolts, the spacer iron horizontal bolts, the guardrail horizontal bolts, and the top iron horizontal bolts.

[0053] Among them, see Figure 6The switch rails used in the wood-to-concrete structure upgrade are: the base rail is made of 50kg / m steel rail, with a length of 7900mm. The straight and lateral switch rails are made of 50AT1 steel rails, with the straight switch rail being 5480mm long (actual length 5035, with the rail waist extending 445mm forward for connecting the tie rods), and the lateral switch rail being 5038mm long. The tips of the two switch rails are at the same starting point. The base rail and the straight switch rail are closely connected by curves to eliminate structural widening. Figure 7 and Figure 8 A top iron is installed on the base rail and lateral point rail after the point rail head is planed to maintain the point rail spacing, allowing the base rail and point rail to jointly withstand horizontal forces. The point rail heel end adopts a double-spacer iron flexible joint structure, with inner and outer rail supports at the heel. The two point rails are actuated by studs and steel sleeves. Two spacer irons are installed behind the point rail heel end to enhance the overall structural stability. Preferably, all spacer irons are machined and then welded to improve assembly accuracy.

[0054] Among them, see Figure 9 The traction points used in the wood-to-concrete structure upgrade are: one traction point is set for each pair of point rails, and there are two pull rods in total at the turnout. The travel at the tip of the point rail is 180mm, and the minimum wheel flange groove is 86mm; slotted joint irons and extended joint irons are used at the overlapping position of the two pull rods to achieve mutual displacement of the two pull rods.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. 7 symmetrical three-way turnout wood to concrete structure upgrade method, characterized by: Use one or more of the following anti-hair loss measures: (1) Adjust the lowering value of the point rail: the tip of the point rail is lowered by 23mm; the 5-section is lowered by 12mm; the 15-section is lowered by 3mm, and the 40-section is lowered by 0mm; the working side of the straight point rail is vertical, and the working side of the lateral point rail adopts a 1:5 slope; (2) The rail supports on the outside of the base rail are removed, and a 320mm long elastic clip is used to clamp the inside of the base rail in the switch section. The elastic clip is designed to have a spring range of 7mm and a clamping force of not less than 11kN. To meet the installation cavity space of the elastic clip, the point rail is raised by 6mm, forming a 30mm height difference between the base and point rails. On the switch sleepers No. 17-19, the height of the guide rail connected to the point rail is gradually lowered by the pad, and the spacing between each sleeper is reduced by 1.5mm. The rail height difference is reduced to 0 on the switch sleeper No.

20. (3) The turnout is equipped with an anti-derail device: the anti-derail device is 3100mm long, with the starting point at 1596mm in front of the tip of the switch rail, the length of the opening section is 150mm, the length of the front buffer section is 1150mm, and the length of the rear buffer section is 700mm; the straight section wheel flange groove is 53mm, divided into two sections: the first section is parallel to the stock rail from 296mm in front of the tip of the switch rail to the 5mm section of the switch rail; the second section is parallel to the closed curved switch rail from the 5mm section of the switch rail to the 15mm section of the switch rail; the upper surface of the active side of the anti-derail device is 22mm higher than the top surface of the stock rail; the non-active side is lowered, and its height is not higher than the upper surface of the working side of the anti-derail device; the lower surface of the working side of the anti-derail device starts to rise from 100mm in front of the tip of the switch rail, and after the 5mm section of the switch rail, the lower surface of the anti-derail device follows the lowering value of the switch rail and maintains a 7mm gap with the top surface of the switch rail; (4) The toe-end length of the middle frog is 1400 + 2190 mm, and the toe-end length of the rear frog is 1550 + 2652 mm. When the vehicle passes through the two rear frogs in a straight line, it is impossible to set up a guardrail separately. Therefore, the straight section of the straight wheel flange groove is extended 150 mm before the theoretical tip to protect the tip of the opposite frog. (5) The guardrail is made of 43kg / m steel rail, and the top surface of the guardrail is 12mm higher than the top surface of the base rail; the wheel flange groove of the straight section of the guardrail is 57mm, and the groove width of the open section is 85mm or 100mm; The parameters that remained unchanged during the wood-to-concrete upgrade included: the turnout's total length was 24,150 mm, with a front length a = 11,465 mm and a rear length b = 12,685 mm. The horizontal alignment adopted a secant circular curve with a 15.78 mm cutoff distance. The tip of the switch rail was a semi-tangent curve. The circular curve radius was 180 m. The switch rail had eight sets of insulation, which remained unchanged. The lateral switch rail tip impact angle was 1.35°, the middle frog guard rail impact angle was 1.33°, and the rear frog guard rail impact angle was 1.55°. The upgrade to a concrete structure includes: no rail bottom or top slopes are set in the turnout area, and slope pads are installed before and after the turnout. Prestressed concrete long turnout sleepers are used under the iron pads. The sleeper spacing in the turnout area is arranged at 550-600mm, with 650mm sleeper spacing at the traction point and 445mm maximum sleeper spacing at the insulating joint at the rear end of the switch. The turnout sleepers are perpendicular to the turnout centerline, with No. 35-49 being combined long turnout sleepers. The switch rails used in the wood-to-concrete structure upgrade are: the base rail is made of 50kg / m steel rail and is 7900mm long; the straight and lateral switch rails are both made of 50AT1 steel rail, with the straight switch rail being 5480mm long and the lateral switch rail being 5038mm long, with the tips of the two switch rails at the same starting point; the base rail and the straight switch rail are closely fitted with a curve, and a top iron is installed on the base rail and the lateral switch rail after the start of the switch rail head planing. The heel end of the switch rail adopts a double spacer iron flexible joint structure, with inner and outer rail supports at the heel. The two switch rails are switched by studs and steel sleeves, and two spacer irons are installed behind the heel end of the switch rail. The traction points used in the wood-to-concrete structure upgrade are: one traction point is set for each pair of point rails, and there are two pull rods at the turnout. The travel at the tip of the point rail is 180mm, and the minimum wheel flange groove is 86mm; slotted joint irons and extended joint irons are used at the overlapping position of the two pull rods to achieve mutual displacement of the two pull rods.

2. The upgrade method according to claim 1, characterized in that: Nylon casing is embedded in the switch sleeper and connected to the pad through switch sleeper bolts. The cross-section of the switch sleeper is an isosceles trapezoid, with a height of 220mm and upper and lower widths of 260mm and 300mm respectively. The main reinforcement is 14 Φ7.0mm prestressed steel wires. Stirrups are provided at both ends of the switch sleeper, and spiral reinforcement is provided on the outside of the casing.

3. The upgrade method according to claim 1, characterized in that: The fastener system used in the wood-to-concrete structure upgrade is: the rails are fastened with separate Type I spring clip fasteners and T-bolts; the No. 11 gauge block is installed on the non-working side of the rail, the No. 13 gauge block is installed on the working side, and 7-17 spare gauge blocks are provided for on-site adjustment to achieve a gauge adjustment range of -12 to +8mm; a separate double-layer elastic structure is used, with a 5mm thick rubber pad under the rail and a 10mm thick rubber pad under the plate.

4. The upgrade method according to claim 3, characterized in that: Rubber pads are used under the plate, oil-resistant rubber pads are used in the switch part, pressure-resistant rubber pads are used in the frog part, and thermoplastic polyester elastomer TPEE is used under the rail.

5. The upgrade method according to claim 1, characterized in that: The pad system used in the wood to concrete structure upgrade is: A full-length connecting pad is set on the guide curve part of the turnout; a support plate and spring bar are added from the heel end of the point rail to the glued rail joint.

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