Catenary plane setting method matched with stretching of large-span steel beam

Abstract

The invention provides an overhead line system plane setting method matched with large-span steel beam expansion and contraction, and belongs to the field of overhead line system design. The method comprises the steps that S1, bridge parameters of a large-span steel truss bridge and overhead line system design parameters are obtained; s2, the maximum expansion and contraction amount of the beam end is calculated with the temperature expansion and contraction zero point as the reference, and the beam body expansion and contraction amount at the center anchoring position and the beam body expansion and contraction amount at the anchoring column lowering position are calculated through linear interpolation; s3, determining the action relationship between the stroke variation of the balance weight caused by bridge expansion and the stroke variation of the balance weight caused by lead expansion, and calculating to obtain the maximum stroke variation of the balance weight; s4, according to the span range of the steel beam, the arrangement positions of the center anchor knot and the anchor section joints on the steel beam section and the concrete beam section are determined; and S5, the mounting height of the anchoring column is adjusted according to the maximum stroke variation of the balance weight. According to the invention, adverse effects on the overhead line system caused by extension and retraction of the large-span steel beam are effectively avoided, and safe and stable operation of the overhead line system is ensured.

Description

Technical Field

[0001] This invention relates to the field of overhead contact line design technology, and in particular to a method for setting up an overhead contact line in a plane to match the expansion and contraction of large-span steel beams. Background Technology

[0002] With the rapid development of electrified railways in my country, large-span steel truss bridges, including those spanning rivers and seas, are increasingly appearing in high-speed railway construction. Large-span steel truss bridges experience significant longitudinal expansion and contraction under the influence of factors such as temperature, live load, braking force, and wind load. This expansion and contraction causes longitudinal displacement of the overhead contact line supports, which in turn affects the system design, including the arrangement of contact line anchor sections, tension compensation devices, and cantilever installation. Compared to concrete bridges and small-span steel beams, large-span steel beams exhibit greater expansion and contraction, resulting in a more significant impact on the contact line system.

[0003] The catenary tension compensation device provides constant working tension to the catenary and contact wire through a series of weights and compensating pulleys. In conventional designs, only the adjustment of the weight stroke caused by conductor expansion due to temperature changes needs to be considered. However, the expansion and contraction displacement of large-span steel beams can reach hundreds of millimeters under adverse conditions, causing changes in the half-anchor section length. This results in the weight stroke variation exceeding the range considered in conventional designs, and in severe cases, the tension compensation device may exceed its effective compensation range or become stuck and fail. In addition, bridge expansion and contraction can also affect the offset of the catenary arms and the installation of additional conductors. If these factors are not comprehensively considered and matched in the design, it may lead to equipment failures and safety accidents such as catenary arm conflicts within the anchor section joints, catenary breakage, or catenary collapse.

[0004] Chinese patent CN103983256A discloses a measurement method for the construction of overhead contact line anchoring in tunnels. This patent relates to the installation and positioning of anchoring devices at anchor joints, using a three-dimensional measuring scale to measure and control the installation positions of compensating pulleys and guide pulleys to solve problems such as uneven wear and derailment of the compensating rope. This technical solution mainly focuses on construction measurement and positioning methods, providing a measuring tool and method to improve the installation accuracy of the anchoring device. However, this patent does not address the impact analysis of the expansion and contraction of large-span steel beams on the planar layout of the overhead contact line, does not establish a quantitative calculation relationship between bridge expansion and contraction and overhead contact line system parameters, and does not provide an optimized layout scheme for overhead contact line anchor sections under different span steel beam conditions. Summary of the Invention

[0005] In view of this, the present invention proposes a method for the planar setting of the contact network to match the expansion and contraction of large-span steel beams. By establishing a quantitative calculation model between bridge expansion and contraction and contact network system parameters, the method determines the relationship between bridge expansion and contraction and the change in the stroke of the weights. Based on the span range of the steel beams, the method provides an optimized arrangement scheme for the contact network anchor sections and anchor columns, thereby effectively avoiding the adverse effects of the expansion and contraction of large-span steel beams on the contact network system and ensuring the safe and stable operation of the contact network system.

[0006] The technical solution of this invention is implemented as follows: This invention provides a method for setting up a contact wire plane to match the expansion and contraction of large-span steel beams, including the following steps: S1. Obtain the bridge parameters and catenary design parameters of the long-span steel truss bridge. The long-span steel truss bridge includes steel beam segments and concrete beam segments at both ends. The bridge parameters include the steel beam span, the steel beam linear expansion coefficient, the design temperature range, and the zero point of temperature expansion and contraction. The catenary design parameters include the anchor length, the center anchor position, the anchor joint position, and the anchor column position. S2. Based on the zero point of temperature expansion, calculate the maximum expansion of the beam end according to the linear expansion coefficient of the steel beam, the design temperature range, and the distance between the beam end and the zero point of temperature expansion. Then, based on the distance between the center anchor position and the zero point of temperature expansion, and the distance between the lower anchor column position and the zero point of temperature expansion, calculate the beam expansion at the center anchor position and the beam expansion at the lower anchor column position respectively by linear interpolation. S3. Based on the positional relationship between the central anchor, the lower anchor column and the zero point of temperature expansion in the longitudinal direction of the bridge, determine the relationship between the bridge expansion and contraction on the change in the weight stroke and the conductor expansion on the change in the weight stroke, and calculate the maximum change in the weight stroke. S4. Determine the arrangement of the central anchorage and anchor joint on the steel beam segment and concrete beam segment according to the span range of the steel beam; S5. Adjust the installation height of the lower anchor column according to the maximum stroke change of the weight.

[0007] Based on the above technical solutions, preferably, step S2 specifically includes: Calculate the maximum expansion and contraction at the beam end based on the steel beam's coefficient of linear expansion, the design temperature range, and the distance between the beam end and the zero point of temperature expansion and contraction: ; in, This indicates the maximum expansion and contraction at the beam end caused by temperature changes. This represents the coefficient of linear expansion of the steel beam. This indicates the highest calculated temperature of the steel beam. This indicates the lowest calculated temperature of the steel beam. This indicates the distance from the end of the bridge beam to the zero point of expansion joint; Obtain the distance between the center anchor position and the zero point of temperature expansion and contraction, as well as the distance between the lower anchor column position and the zero point of temperature expansion and contraction; Using the zero point of temperature expansion as the center, the maximum longitudinal expansion and contraction of the beam at the central anchorage and the maximum longitudinal expansion and contraction of the beam at the lower anchorage are calculated separately using linear interpolation: ; in, This represents the distance between any point on the beam and the zero point of thermal expansion and contraction of the steel beam. This represents the maximum amount of expansion and contraction at any point on the beam.

[0008] Based on the above technical solutions, preferably, step S3 specifically includes: By comparing the distance between the center anchor and the zero point of temperature expansion and the distance between the lower anchor and the zero point of temperature expansion, the relationship between the bridge expansion and contraction on the change in the weight travel and the conductor expansion on the change in the weight travel is determined. Determine the cause of the change in the weight's travel based on the interaction relationship, and calculate the maximum change in the weight's travel.

[0009] Based on the above technical solutions, the preferred one is... The relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor cable expansion affecting the change in the weight's travel includes both a superposition relationship and an inverse relationship. When the distance between the central anchor and the zero point of temperature expansion is less than the distance between the lower anchor and the zero point of temperature expansion, the relationship between the effect of bridge expansion and contraction on the change of the weight travel and the effect of conductor expansion on the change of the weight travel is superimposed. When the distance between the central anchor and the zero point of temperature expansion is greater than the distance between the lower anchor and the zero point of temperature expansion, the relationship between the bridge expansion and contraction on the change in the weight travel and the influence of the conductor expansion on the change in the weight travel is inverse.

[0010] Based on the above technical solutions, the preferred one is... When the interaction is superimposed, the change in the weight's travel is caused by the conductor, and the change in the weight's travel... The calculation formula is: ; ; in, This refers to the transmission ratio of the tension compensation device. The coefficient of linear expansion of the conductor. This refers to the range of temperature variation in the conductor. This is half the anchorage length. This refers to the change in the length of the half-anchor section caused by bridge expansion and contraction. This indicates the maximum displacement of the beam caused by live load, braking force, and wind load. This indicates the expansion length of the lower anchor section of the bridge.

[0011] Based on the above technical solutions, the preferred one is... When the interaction is reversed, the change in the weight's stroke is caused by the bridge's expansion and contraction, and the maximum change in the weight's stroke... The calculation formula is: ; ; in, This refers to the transmission ratio of the tension compensation device. The coefficient of linear expansion of the conductor. This refers to the range of temperature variation in the conductor. This is half the anchorage length. This refers to the change in the length of the half-anchor section caused by bridge expansion and contraction. This indicates the distance between the center anchor and the zero point of temperature expansion. This indicates the distance between the anchor post and the zero point of temperature expansion / contraction.

[0012] Based on the above technical solutions, preferably, step S4 specifically includes: Determine the span range of the steel beam: When the span of the steel beam is less than 720 meters, the central anchor is placed at the zero point of temperature expansion and contraction, and the anchor joint is placed on the concrete beam segment. When the steel beam span is 720 to 849 meters, the anchor joint is placed at the zero point of temperature expansion and contraction, and the center anchor is placed on the concrete beam segment. When the span of the steel beam is 850 to 1900 meters, the central anchor is placed at the zero point of temperature expansion and contraction, the anchor joint is placed on the steel beam segment and close to the expansion joint between the steel beam segment and the concrete beam segment, and the central anchor outside the anchor joint is placed on the concrete beam segment. When the span of the steel beam is greater than 1900 meters, the central anchorage is arranged on the concrete beam segment, and the length of the anchorage spanning the expansion joint is set to be less than the length of the anchorage on the steel beam segment.

[0013] Based on the above technical solutions, preferably, step S5 specifically includes: The installation height of the contact wire anchor support relative to the rail surface is calculated based on the maximum stroke change of the weight, the working support height of the contact wire, the non-support elevation of the contact wire conversion column, the height difference between the support foundation surface and the rail surface, the minimum distance from the bottom of the weight string to the support foundation surface, the total length of the weight string, and the minimum height of the top surface of the weight string from the anchor point of the contact wire. The height of the lower anchor support is determined based on the installation height of the contact wire anchor support. The installation parameters of the tension compensation device are adjusted according to the maximum stroke change of the weight. The installation parameters of the tension compensation device include b value and a value, where b value represents the distance from the bottom of the weight to the support foundation surface after the initial elongation of the newly erected conductor, and a value represents the distance between the ratchet assembly and the balance wheel.

[0014] Based on the above technical solutions, the preferred formula for calculating the installation height of the contact wire anchor support is: in, Indicates the installation height of the contact wire anchor support. Indicates the working support height of the contact wire. This indicates the non-supported elevation of the contact wire conversion post. This indicates the height difference between the support foundation surface and the rail surface. This indicates the minimum distance from the bottom of the weight string to the foundation surface of the support column, considering only linear expansion and contraction. This indicates the total length of the weight string. This indicates the maximum change in the travel of the weight. This indicates the minimum height from the top surface of the weight string to the anchor point below the contact line.

[0015] More preferably, the method for calculating the installation parameters of the tension compensation device includes: When the anchor column and the central anchor are not simultaneously arranged in a large-span steel beam: If the effects of bridge expansion / contraction on the change in weight travel and the effects of conductor expansion on the change in weight travel are superimposed, then the formulas for calculating the values ​​of b and a are: ; ; If the relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor expansion affecting the change in the weight's travel is inverse, then the formulas for calculating the values ​​of b and a are: ; ; When anchor columns and central anchors are simultaneously arranged in a long-span steel beam: If the effects of bridge expansion / contraction on the change in weight travel and the effects of conductor expansion on the change in weight travel are superimposed, then the formulas for calculating the values ​​of b and a are: ; ; If the relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor expansion affecting the change in the weight's travel is inverse, then the formulas for calculating the values ​​of b and a are: ; ; in, This indicates the minimum distance from the bottom of the weight string to the foundation surface of the support column, considering only the expansion and contraction of the line. This indicates the minimum distance between the ratchet assembly and the balance wheel at the highest temperature after the initial elongation of the conductor has been completed, considering only the expansion and contraction of the conductor. Indicates the initial elongation coefficient of a new copper alloy conductor. This indicates the temperature during the installation and adjustment of the contact suspension conductor weight. This indicates the real-time temperature of the bridge beam. This indicates the highest calculated temperature of the contact suspension conductor. This indicates the highest calculated temperature of the steel beam.

[0016] The contact wire planar setting method for matching the expansion and contraction of large-span steel beams according to the present invention has the following advantages over the prior art: (1) By establishing a quantitative calculation relationship between the bridge temperature expansion and contraction parameters and the expansion and contraction of the contact network at key locations, and taking the zero point of temperature expansion and contraction as the benchmark, the beam expansion and contraction at the central anchor position and the lower anchor column position are calculated by linear interpolation method, which effectively avoids the adverse effects of the expansion and contraction of large-span steel beams on the contact network system and ensures the safe and stable operation of the contact network system. (2) Based on the positional relationship between the central anchor, the lower anchor column and the zero point of temperature expansion in the longitudinal direction of the bridge, the superposition relationship or inverse relationship between the bridge expansion and the change in the weight stroke and the change in the weight stroke due to the expansion of the conductor were determined, and a corresponding calculation method was established. By distinguishing different action relationships and calculating the maximum change in the weight stroke separately, the actual working condition of the tension compensation device can be accurately assessed, providing a reliable basis for adjusting the installation height of the lower anchor column and the installation parameters of the tension compensation device, and effectively avoiding the risk of the tension compensation device exceeding the effective compensation range or becoming stuck and failing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam according to the present invention; Figure 2 This is a schematic diagram of the contact wire planar arrangement scenario 1 for a contact wire planar setting method for matching the expansion and contraction of a large-span steel beam according to the present invention; Figure 3 This is a schematic diagram of contact wire planar arrangement scenario 2 for a contact wire planar setting method for matching the expansion and contraction of large-span steel beams according to the present invention; Figure 4 This is a schematic diagram of contact wire planar arrangement scenario 3 for a contact wire planar setting method for matching the expansion and contraction of large-span steel beams according to the present invention; Figure 5This is a schematic diagram of the contact wire planar arrangement scenario 4, which is a contact wire planar setting method for matching the expansion and contraction of a large-span steel beam according to the present invention. Figure 6 This is a schematic diagram of contact wire planar arrangement scenario 5, which is a contact wire planar setting method for matching the expansion and contraction of large-span steel beams according to the present invention. Figure 7 This is a schematic diagram of the contact wire planar arrangement scenario 6, which is a contact wire planar setting method for matching the expansion and contraction of a large-span steel beam according to the present invention. Figure 8 This is a schematic diagram of the anchor weight installation curve for a contact wire planar setting method for matching the expansion and contraction of a large-span steel beam according to the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the present invention provides a method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam, comprising the following steps: S1. Obtain the bridge parameters and catenary design parameters of the long-span steel truss bridge. The long-span steel truss bridge includes steel beam segments and concrete beam segments at both ends. The bridge parameters include the steel beam span, the steel beam linear expansion coefficient, the design temperature range, and the zero point of temperature expansion and contraction. The catenary design parameters include the anchor length, the center anchor position, the anchor joint position, and the anchor column position.

[0021] Understandably, the zero-point location of temperature expansion refers to the point where the longitudinal expansion and contraction displacement of the steel beam is zero under the influence of temperature changes. It is typically located near the middle of the beam span, and its specific location is determined by the bridge structure and support arrangement. Anchor segment length refers to the length of the contact wire between anchor segment joints; center anchorage location refers to the position of the center anchorage at the midpoint of the anchor segment; anchor segment joint location refers to the boundary point between two adjacent anchor segments; and anchor post location refers to the position of the lower anchor post. These parameters are initially determined based on the contact wire system design requirements and line conditions, and are optimized and adjusted in subsequent design processes based on the effects of steel beam expansion and contraction.

[0022] This invention establishes a quantitative calculation relationship between the temperature expansion and contraction parameters of bridges and the expansion and contraction at key locations of the overhead contact system. Using the zero point of temperature expansion and contraction as a benchmark, it employs a linear interpolation method to calculate the beam expansion and contraction at the central anchorage and lower anchorage positions. The calculation process is clear and easy to apply in engineering, enabling designers to accurately grasp the impact of the expansion and contraction of large-span steel beams on the overhead contact system.

[0023] S2. Based on the zero point of temperature expansion, calculate the maximum expansion of the beam end according to the linear expansion coefficient of the steel beam, the design temperature range, and the distance between the beam end and the zero point of temperature expansion. Then, based on the distance between the center anchor position and the zero point of temperature expansion, and the distance between the lower anchor column position and the zero point of temperature expansion, calculate the beam expansion at the center anchor position and the beam expansion at the lower anchor column position respectively by linear interpolation. Specifically, step S2 includes: Calculate the maximum expansion and contraction at the beam end based on the steel beam's coefficient of linear expansion, the design temperature range, and the distance between the beam end and the zero point of temperature expansion and contraction: ; in, This indicates the maximum expansion and contraction at the beam end caused by temperature changes. This represents the coefficient of linear expansion of the steel beam. This indicates the highest calculated temperature of the steel beam. This indicates the lowest calculated temperature of the steel beam. This indicates the distance from the end of the bridge beam to the zero point of expansion joint; Obtain the distance between the center anchor position and the zero point of temperature expansion and contraction, as well as the distance between the lower anchor column position and the zero point of temperature expansion and contraction; Using the zero point of temperature expansion as the center, the maximum longitudinal expansion and contraction of the beam at the central anchorage and the maximum longitudinal expansion and contraction of the beam at the lower anchorage are calculated separately using linear interpolation: ; in, This represents the distance between any point on the beam and the zero point of thermal expansion and contraction of the steel beam. This represents the maximum amount of expansion and contraction at any point on the beam.

[0024] Understandably, steel truss bridges are mainly affected by temperature, braking force, wind load, and live load, resulting in longitudinal displacement and expansion. Temperature-induced bridge expansion includes both linear and gradient temperature changes. Linear temperature changes cause significant longitudinal expansion due to beam deformation, while gradient temperature changes primarily affect the bridge structure through stress changes, leading to relatively smaller longitudinal expansion. These stress changes are generally considered uniformly in the safety factor when calculating bridge expansion. Braking force and longitudinal wind load cause relatively small longitudinal displacements, resulting in overall displacement of the steel beam; that is, the longitudinal displacement at any position of the steel beam is consistent with that at the beam end. Under live load, the expansion and contraction at different positions of the steel beam vary and are complex, with the maximum deformation generally located at the beam end. Given the relatively small impact of live load on steel beam expansion, the limit state method is adopted for calculation, assuming that the displacement at any position of the steel beam under live load is consistent with that at the beam end. This invention uses... This indicates the maximum displacement of the beam caused by live load, braking force, and wind load.

[0025] When any point on the beam is the central anchorage location = When any point on the beam is the location of the lower anchor column, = .

[0026] In one embodiment of the present invention, a bridge is used in The calculation is based on the premise that the elongation of the beam is zero at a given temperature. For example, if the expansion and contraction range at the end of a steel truss bridge due to temperature is ±0.3m, then... .

[0027] S3. Based on the positional relationship between the central anchor, the lower anchor column, and the zero point of temperature expansion in the longitudinal direction of the bridge, determine the interaction between bridge expansion and contraction on the change in the weight's travel and the effect of conductor line expansion on the change in the weight's travel, and calculate the maximum change in the weight's travel. The interaction between bridge expansion and contraction on the change in the weight's travel and the effect of conductor line expansion on the change in the weight's travel includes both superposition and inverse relationships. When the distance between the central anchor and the zero point of temperature expansion is less than the distance between the lower anchor and the zero point of temperature expansion, the relationship between the effect of bridge expansion and contraction on the change of the weight travel and the effect of conductor expansion on the change of the weight travel is superimposed. When the distance between the central anchor and the zero point of temperature expansion is greater than the distance between the lower anchor and the zero point of temperature expansion, the relationship between the bridge expansion and contraction on the change in the weight travel and the influence of the conductor expansion on the change in the weight travel is inverse.

[0028] Understandably, bridge expansion and contraction will cause displacement of the catenary supports, which in turn affects the length of the semi-anchor sections, leading to the raising and lowering of the weights. The catenary tension compensation device provides a constant working tension to the catenary and contact wire through the weight string and compensation pulleys. In conventional designs, the installation of the tension compensation device only needs to consider the adjustment caused by the linear change in conductor expansion with temperature. Specifically, when the temperature rises, the conductor elongates, causing the weights to lower; when the temperature falls, the conductor shortens, causing the weights to rise. However, the expansion and contraction displacement of large-span steel beams is significant, which has a substantial impact on the design of the catenary system, especially the installation of the tension compensation device. Under unfavorable conditions, situations may arise where the compensation exceeds the effective range.

[0029] Based on the positional relationship between the central anchor, the lower anchor post, and the zero point of temperature expansion in the longitudinal direction of the bridge, this invention determines the superposition or inverse relationship between the bridge expansion and contraction affecting the change in the weight travel and the conductor expansion affecting the weight travel. A corresponding calculation method is established. By distinguishing different action relationships and calculating the maximum change in weight travel separately, the actual working condition of the tension compensation device can be accurately assessed. This provides a reliable basis for adjusting the installation height of the lower anchor post and the installation parameters of the tension compensation device, effectively avoiding the risk of the tension compensation device exceeding its effective compensation range or becoming stuck and failing.

[0030] Specifically, step S3 includes: By comparing the distance between the center anchor and the zero point of temperature expansion and the distance between the lower anchor and the zero point of temperature expansion, the relationship between the bridge expansion and contraction on the change in the weight travel and the conductor expansion on the change in the weight travel is determined. Determine the cause of the change in the weight's travel based on the interaction relationship, and calculate the maximum change in the weight's travel.

[0031] Furthermore, When the interaction is superimposed, the change in the weight's travel is caused by the conductor, and the change in the weight's travel... The calculation formula is: ; ; in, This refers to the transmission ratio of the tension compensation device. The coefficient of linear expansion of the conductor. This refers to the range of temperature variation in the conductor. This is half the anchorage length. This refers to the change in the length of the half-anchor section caused by bridge expansion and contraction. This indicates the maximum displacement of the beam caused by live load, braking force, and wind load. This indicates the expansion length of the lower anchor section of the bridge.

[0032] In one embodiment of the present invention, When the interaction is reversed, the change in the weight's stroke is caused by the bridge's expansion and contraction, and the maximum change in the weight's stroke... The calculation formula is: ; ; in, This refers to the transmission ratio of the tension compensation device. The coefficient of linear expansion of the conductor. This refers to the range of temperature variation in the conductor. This is half the anchorage length. This refers to the change in the length of the half-anchor section caused by bridge expansion and contraction. This indicates the distance between the center anchor and the zero point of temperature expansion. This indicates the distance between the anchor post and the zero point of temperature expansion / contraction.

[0033] S4. Determine the arrangement of the central anchorage and anchor joint on the steel beam segment and concrete beam segment according to the span range of the steel beam; Specifically, step S4 includes: Determine the span range of the steel beam: When the span of the steel beam is less than 720 meters, the central anchor is placed at the zero point of temperature expansion and contraction, and the anchor joint is placed on the concrete beam segment. When the steel beam span is 720 to 849 meters, the anchor joint is placed at the zero point of temperature expansion and contraction, and the center anchor is placed on the concrete beam segment. When the span of the steel beam is 850 to 1900 meters, the central anchor is placed at the zero point of temperature expansion and contraction, the anchor joint is placed on the steel beam segment and close to the expansion joint between the steel beam segment and the concrete beam segment, and the central anchor outside the anchor joint is placed on the concrete beam segment. When the span of the steel beam is greater than 1900 meters, the central anchorage is arranged on the concrete beam segment, and the length of the anchorage spanning the expansion joint is set to be less than the length of the anchorage on the steel beam segment.

[0034] Six common contact wire layout scenarios for long-span steel beam sections are as follows: Figures 2-7As shown in Table 1, when the middle anchor is located on a large-span steel beam and far from the zero point of the steel beam's expansion and contraction, the anchor column B and the middle anchor are located on the same side of the zero point of the steel beam's expansion and contraction. When the middle anchor is located on a large-span steel beam and far from the zero point of the steel beam's expansion and contraction, the anchor column B and the middle anchor are located on opposite sides of the zero point of the steel beam's expansion and contraction. When the middle anchor is located on a concrete bridge, the upper joint of the steel beam is close to the beam end. When the middle anchor is located on a concrete bridge, the upper joint of the steel beam is close to the zero point of expansion and contraction (steel beam length is 720~849m). When the middle anchor is located on a large-span steel beam and close to the zero point of the steel beam's expansion and contraction (steel beam length is less than 720m). When the middle anchor is located on a large-span steel beam and close to the zero point of the steel beam's expansion and contraction (steel beam length is 850~1900m), the relationship between the effects of steel beam expansion and contraction and conductor expansion and contraction on the raising and lowering of the weight under temperature is compared.

[0035] Table 1: Comparison of the effects of steel beam expansion and contraction and conductor expansion and contraction on the lifting and lowering of the weight under temperature effects It is evident that a differentiated anchor section arrangement strategy was proposed based on the different span ranges of the steel beams, which can effectively reduce the adverse effects of steel beam expansion and contraction on the contact network system and improve the operational reliability of the contact network system.

[0036] S5. Adjust the installation height of the lower anchor column according to the maximum stroke change of the weight.

[0037] Specifically, step S5 includes: The installation height of the contact wire anchor support relative to the rail surface is calculated based on the maximum stroke change of the weight, the working support height of the contact wire, the non-support elevation of the contact wire conversion column, the height difference between the support foundation surface and the rail surface, the minimum distance from the bottom of the weight string to the support foundation surface, the total length of the weight string, and the minimum height of the top surface of the weight string from the anchor point of the contact wire. The height of the lower anchor support is determined based on the installation height of the contact wire anchor support. The installation parameters of the tension compensation device are adjusted according to the maximum stroke change of the weight. The installation parameters of the tension compensation device include b value and a value, where b value represents the distance from the bottom of the weight to the support foundation surface after the initial elongation of the newly erected conductor, and a value represents the distance between the ratchet assembly and the balance wheel.

[0038] Understandably, in conventional designs, the installation height of the contact wire anchorage is mainly determined by the height of the contact wire conductor and the non-support elevation of the contact wire transition post, with little consideration given to the impact of changes in the weight travel on the installation height. However, the expansion and contraction of large-span steel beams can affect the weight travel variation of the contact wire tension compensation device by several meters under adverse conditions. This range of weight travel variation exceeds the conventional design range, necessitating a corresponding increase in the installation height of the contact wire anchorage to ensure the tension compensation device functions properly under various operating conditions.

[0039] Furthermore, the formula for calculating the installation height of the contact wire anchor is as follows: in, Indicates the installation height of the contact wire anchor support. Indicates the working support height of the contact wire. This indicates the non-supported elevation of the contact wire conversion post. This indicates the height difference between the support foundation surface and the rail surface. This indicates the minimum distance from the bottom of the weight string to the foundation surface of the support column, considering only linear expansion and contraction. This indicates the total length of the weight string. This indicates the maximum change in the travel of the weight. This indicates the minimum height from the top surface of the weight string to the anchor point below the contact line.

[0040] In one embodiment of the present invention, the non-supported elevation of the contact wire conversion post is... The value is 0.5m.

[0041] In one embodiment of the present invention, the method for calculating the installation parameters of the tension compensation device includes: When the anchor column and the central anchor are not simultaneously arranged in a large-span steel beam: If the effects of bridge expansion / contraction on the change in weight travel and the effects of conductor expansion on the change in weight travel are superimposed, then the formulas for calculating the values ​​of b and a are: ; ; If the relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor expansion affecting the change in the weight's travel is inverse, then the formulas for calculating the values ​​of b and a are: ; ; When anchor columns and central anchors are simultaneously arranged in a long-span steel beam: If the effects of bridge expansion / contraction on the change in weight travel and the effects of conductor expansion on the change in weight travel are superimposed, then the formulas for calculating the values ​​of b and a are: ; ; If the relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor expansion affecting the change in the weight's travel is inverse, then the formulas for calculating the values ​​of b and a are: ; ; in, This indicates the minimum distance from the bottom of the weight string to the foundation surface of the support column, considering only the expansion and contraction of the line. This indicates the minimum distance between the ratchet assembly and the balance wheel at the highest temperature after the initial elongation of the conductor has been completed, considering only the expansion and contraction of the conductor. Indicates the initial elongation coefficient of a new copper alloy conductor. This indicates the temperature during the installation and adjustment of the contact suspension conductor weight. This indicates the real-time temperature of the bridge beam. This indicates the highest calculated temperature of the contact suspension conductor. This indicates the highest calculated temperature of the steel beam.

[0042] Understandably, when the anchor columns and the central anchor are not simultaneously arranged in a large-span steel beam, the beam displacement caused by live load, braking force, and wind load will be significant. The temperature affects the raising and lowering of the weight, and this needs to be considered in the calculation of the b and a values. In the superposition relationship, increased temperature causes the steel beam to elongate, the half-anchor length to shorten, and the weight to lower, resulting in a decrease in both b and a values; decreased temperature causes the steel beam to shorten, the half-anchor length to lengthen, and the weight to rise, resulting in an increase in both b and a values. In the reverse relationship, increased temperature causes the steel beam to elongate, the half-anchor length to lengthen, and the weight to rise, resulting in an increase in both b and a values; decreased temperature causes the steel beam to shorten, the half-anchor length to shorten, and the weight to lower, resulting in a decrease in both b and a values.

[0043] When anchor columns and central anchors are simultaneously arranged in a large-span steel beam, It has no effect on the rise and fall of the weight; the formulas for calculating the b and a values ​​do not include... In the case of superposition, the temperature term in the calculation formula is... When the relationship is reversed, the temperature term in the calculation formula is: Actual temperature at the steel beam bridge site It varies randomly and is closely related to factors such as the bridge's geographical location, orientation, temperature, wind speed, solar radiation intensity, rain, and fog. It is difficult to measure accurately in practical engineering applications and can be approximated by taking the value based on the ambient temperature at the site.

[0044] Tension compensation devices affected by bridge expansion and contraction should preferably use iron weights to improve the stability and reliability of the device. For large-span steel beams used for both road and rail transport with the railway located underneath, the minimum clearance design requirements of the overhead contact system for the bridge should be determined comprehensively based on factors such as the installation height of the contact wire anchorages; if the bridge clearance is limited, the overhead contact system needs to be designed according to a comprehensive study of the bridge clearance system.

[0045] This invention calculates the maximum stroke variation of the weight, comprehensively considers multiple parameters such as the working support height of the contact wire, the non-support elevation of the contact wire conversion column, and the height difference between the support foundation surface and the rail surface, to determine the installation height of the anchor column. It then adjusts the installation parameters of the tension compensation device, such as the b-value and a-value, accordingly to ensure that the tension compensation device can work normally under various operating conditions. This avoids contact wire failures caused by weight stroke variations exceeding the design range, thus guaranteeing the safe operation of high-speed railways.

[0046] In a specific embodiment, the weights for anchor A (with a superimposed relationship) and anchor B (with a reverse relationship) are used. b The following explanation is based on a typical installation curve: Anchor A: ; Anchor B: The installation curve is affected by the actual temperature of the conductor. and the actual temperature of the steel beam Both variables have an effect, and and There is no direct correspondence between them. Assume... Theoretical calculations were performed and a typical anchor weight installation curve was obtained, such as... Figure 8 As shown, where This indicates the lowest calculated temperature for the contact suspension conductor.

[0047] High-speed rail = Taking a 5.3m contact line with a CTMH150 (tension 30kN) as an example, the maximum travel range of the anchor A weight is as follows: = 5.16m; Figure 2 The anchoring height of the contact wire of the middle anchor post A is: = = 7.76m; The contact wire needs to be raised. = After anchoring at 2.46m, the contact line at the transition post has been raised by 0.5m. The minimum span required for the contact line to be raised by another 1.96m from the transition post is 93m. Therefore, the anchor section joint non-support should be anchored at least one span longer.

[0048] 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 within the protection scope of the present invention.

Claims

1. A method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam, characterized in that: Includes the following steps: S1. Obtain the bridge parameters and catenary design parameters of the long-span steel truss bridge. The long-span steel truss bridge includes steel beam segments and concrete beam segments at both ends. The bridge parameters include the steel beam span, the steel beam linear expansion coefficient, the design temperature range, and the zero point of temperature expansion and contraction. The catenary design parameters include the anchor length, the center anchor position, the anchor joint position, and the anchor column position. S2. Based on the zero point of temperature expansion, calculate the maximum expansion of the beam end according to the linear expansion coefficient of the steel beam, the design temperature range, and the distance between the beam end and the zero point of temperature expansion. Then, based on the distance between the center anchor position and the zero point of temperature expansion, and the distance between the lower anchor column position and the zero point of temperature expansion, calculate the beam expansion at the center anchor position and the beam expansion at the lower anchor column position respectively by linear interpolation. S3. Based on the positional relationship between the central anchor, the lower anchor column and the zero point of temperature expansion in the longitudinal direction of the bridge, determine the relationship between the bridge expansion and contraction on the change in the weight stroke and the conductor expansion on the change in the weight stroke, and calculate the maximum change in the weight stroke. S4. Determine the arrangement of the central anchorage and anchor joint on the steel beam segment and concrete beam segment according to the span range of the steel beam; S5. Adjust the installation height of the lower anchor column according to the maximum stroke change of the weight.

2. The contact wire planar setting method for matching the expansion and contraction of large-span steel beams as described in claim 1, characterized in that: Step S2 specifically includes: Calculate the maximum expansion and contraction at the beam end based on the steel beam's coefficient of linear expansion, the design temperature range, and the distance between the beam end and the zero point of temperature expansion and contraction: ； in, This indicates the maximum expansion and contraction at the beam end caused by temperature changes. This represents the coefficient of linear expansion of the steel beam. This indicates the highest calculated temperature of the steel beam. This indicates the lowest calculated temperature of the steel beam. This indicates the distance from the end of the bridge beam to the zero point of expansion joint; Obtain the distance between the center anchor position and the zero point of temperature expansion and contraction, as well as the distance between the lower anchor column position and the zero point of temperature expansion and contraction; Using the zero point of temperature expansion as the center, the maximum longitudinal expansion and contraction of the beam at the central anchorage and the maximum longitudinal expansion and contraction of the beam at the lower anchorage are calculated separately using linear interpolation: ； in, This represents the distance between any point on the beam and the zero point of thermal expansion and contraction of the steel beam. This represents the maximum amount of expansion and contraction at any point on the beam.

3. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 2, characterized in that: Step S3 specifically includes: By comparing the distance between the center anchor and the zero point of temperature expansion and the distance between the lower anchor and the zero point of temperature expansion, the relationship between the bridge expansion and contraction on the change in the weight travel and the conductor expansion on the change in the weight travel is determined. Determine the cause of the change in the weight's travel based on the interaction relationship, and calculate the maximum change in the weight's travel.

4. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 3, characterized in that: The relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor cable expansion affecting the change in the weight's travel includes both a superposition relationship and an inverse relationship. When the distance between the central anchor and the zero point of temperature expansion is less than the distance between the lower anchor and the zero point of temperature expansion, the relationship between the effect of bridge expansion and contraction on the change of the weight travel and the effect of conductor expansion on the change of the weight travel is superimposed. When the distance between the central anchor and the zero point of temperature expansion is greater than the distance between the lower anchor and the zero point of temperature expansion, the relationship between the bridge expansion and contraction on the change in the weight travel and the influence of the conductor expansion on the change in the weight travel is inverse.

5. The contact wire planar setting method for matching the expansion and contraction of large-span steel beams as described in claim 4, characterized in that: When the interaction is superimposed, the change in the weight's travel is caused by the conductor, and the change in the weight's travel... The calculation formula is: ； ； in, This refers to the transmission ratio of the tension compensation device. The coefficient of linear expansion of the conductor. This refers to the range of temperature variation in the conductor. This is half the anchorage length. This refers to the change in the length of the half-anchor section caused by bridge expansion and contraction. This indicates the maximum displacement of the beam caused by live load, braking force, and wind load. This indicates the expansion length of the lower anchor section of the bridge.

6. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 4, characterized in that: When the interaction is reversed, the change in the weight's stroke is caused by the bridge's expansion and contraction, and the maximum change in the weight's stroke... The calculation formula is: ； ； in, This refers to the transmission ratio of the tension compensation device. The coefficient of linear expansion of the conductor. This refers to the range of temperature variation in the conductor. This is half the anchorage length. This refers to the change in the length of the half-anchor section caused by bridge expansion and contraction. This indicates the distance between the center anchor and the zero point of temperature expansion. This indicates the distance between the anchor post and the zero point of temperature expansion / contraction.

7. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 1, characterized in that: Step S4 specifically includes: Determine the span range of the steel beam: When the span of the steel beam is less than 720 meters, the central anchor is placed at the zero point of temperature expansion and contraction, and the anchor joint is placed on the concrete beam segment. When the steel beam span is 720 to 849 meters, the anchor joint is placed at the zero point of temperature expansion and contraction, and the center anchor is placed on the concrete beam segment. When the span of the steel beam is 850 to 1900 meters, the central anchor is placed at the zero point of temperature expansion and contraction, the anchor joint is placed on the steel beam segment and close to the expansion joint between the steel beam segment and the concrete beam segment, and the central anchor outside the anchor joint is placed on the concrete beam segment. When the span of the steel beam is greater than 1900 meters, the central anchorage is arranged on the concrete beam segment, and the length of the anchorage spanning the expansion joint is set to be less than the length of the anchorage on the steel beam segment.

8. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 5, characterized in that: Step S5 specifically includes: The installation height of the contact wire anchor support relative to the rail surface is calculated based on the maximum stroke change of the weight, the working support height of the contact wire, the non-support elevation of the contact wire conversion column, the height difference between the support foundation surface and the rail surface, the minimum distance from the bottom of the weight string to the support foundation surface, the total length of the weight string, and the minimum height of the top surface of the weight string from the anchor point of the contact wire. The height of the lower anchor support is determined based on the installation height of the contact wire anchor support. The installation parameters of the tension compensation device are adjusted according to the maximum stroke change of the weight. The installation parameters of the tension compensation device include b value and a value, where b value represents the distance from the bottom of the weight to the support foundation surface after the initial elongation of the newly erected conductor, and a value represents the distance between the ratchet assembly and the balance wheel.

9. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 8, characterized in that: The formula for calculating the installation height of the contact wire anchor is: ； in, Indicates the installation height of the contact wire anchor support. Indicates the working support height of the contact wire. This indicates the non-supported elevation of the contact wire conversion post. This indicates the height difference between the support foundation surface and the rail surface. This indicates the minimum distance from the bottom of the weight string to the foundation surface of the support column, considering only linear expansion and contraction. This indicates the total length of the weight string. This indicates the maximum change in the travel of the weight. This indicates the minimum height from the top surface of the weight string to the anchor point below the contact line.

10. The method for setting up a contact wire plane to match the expansion and contraction of a large-span steel beam as described in claim 9, characterized in that: The calculation method for the installation parameters of the tension compensation device includes: When the anchor column and the central anchor are not simultaneously arranged in a large-span steel beam: If the effects of bridge expansion / contraction on the change in weight travel and the effects of conductor expansion on the change in weight travel are superimposed, then the formulas for calculating the values ​​of b and a are: ； ； If the relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor expansion affecting the change in the weight's travel is inverse, then the formulas for calculating the values ​​of b and a are: ； ； When anchor columns and central anchors are simultaneously arranged in a long-span steel beam: If the effects of bridge expansion / contraction on the change in weight travel and the effects of conductor expansion on the change in weight travel are superimposed, then the formulas for calculating the values ​​of b and a are: ； ； If the relationship between the bridge expansion / contraction affecting the change in the weight's travel and the conductor expansion affecting the change in the weight's travel is inverse, then the formulas for calculating the values ​​of b and a are: ； ； in, This indicates the minimum distance from the bottom of the weight string to the foundation surface of the support column, considering only the expansion and contraction of the line. This indicates the minimum distance between the ratchet assembly and the balance wheel at the highest temperature after the initial elongation of the conductor has been completed, considering only the expansion and contraction of the conductor. Indicates the initial elongation coefficient of a new copper alloy conductor. This indicates the temperature during the installation and adjustment of the contact suspension conductor weight. This indicates the real-time temperature of the bridge beam. This indicates the highest calculated temperature of the contact suspension conductor. This indicates the highest calculated temperature of the steel beam.

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