High-speed rail transit sound barrier design method

Abstract

The invention provides a high-speed rail transit sound barrier design method, which comprises the following steps of: enabling noise generated by operation of a high-speed rail transit vehicle to be equivalent to a combined sound source in different areas to serve as an equivalent sound source; the equivalent sound source serves as a fixed sound source, the time interval of train movement is converted into the distance interval of measuring points in the length direction of a line, and an infinite long sound barrier structure type, the height of a vertical sound barrier or the closed area of a closed sound barrier meeting the noise emission standard are obtained through iterative calculation; and taking the equivalent sound source as a mobile sound source, and obtaining the structural type, the size and the end extension amount of the sound barrier meeting the emission noise standard through iterative calculation. According to the design method, the optimal design scheme of the sound barrier is comprehensively obtained from economy, structural safety and the noise reduction effect according to the sound production characteristics of the high-speed rail transit, the design reasonability is improved, and the noise reduction design requirement of the high-speed rail transit is better met.

Description

Technical Field

[0001] The present invention belongs to the technical field of acoustic design of sound barriers, and in particular, is a method for accurately determining the type, height and end length of a sound barrier based on the size and characteristics of noise emitted by high-speed rail transit vehicles. Background Art

[0002] As a measure to prevent noise propagation, sound barriers are the most widely used and most expensive project in the field of rail transit noise reduction. In recent years, with the speed-up test and research of high-speed railway projects and the research and promotion of high-speed maglev transportation systems, the sound source size and environmental noise impact of future ultra-high-speed (speed 400km / h and above) rail transit will exceed that of rail transit under current technical standards, and the demand for noise reduction of sound barriers will also be further increased.

[0003] The bridge section of the 350km / h high-speed railway mainly adopts 2.3m high and 3.3m high vertical sound barriers, and the roadbed section mainly adopts 3m high and 4m high vertical sound barriers to meet the standard requirements of "Railway Boundary Noise Limits and Their Measurement Methods" (GB12525-90), which is 70dB (A) during the day and 60dB (A) at 30m from the center line of the outer track and 1.2m from the ground. At present, some high-speed railways have implemented fully enclosed and semi-enclosed sound barriers.

[0004] However, the higher the height of the vertical sound barrier is and the more closed the line is due to the closed sound barrier, the greater the vehicle-induced aerodynamic load acting on the sound barrier, and the stiffness requirement of the overall structure of the sound barrier increases, resulting in an increase in the size of the structural components in the design, which in turn increases the investment in the sound barrier, makes the construction process more complex, and further improves the construction accuracy requirements. At the same time, in addition to increasing the height of the vertical sound barrier or the closed area of ​​the closed sound barrier to increase the noise reduction effect of the sound barrier, increasing the end extension of the same type and size of the sound barrier will also increase the noise reduction effect of the protection target in the sound shadow area of ​​the sound barrier. The current design does not consider the influence of different protection target positions, line technical conditions (track surface height, line structure type, column flow, etc.), different sound barrier heights or types, etc. on the end extension of the sound barrier (generally, the end extension of the sound barrier design is considered to be 50m), and cannot effectively combine the noise reduction requirements at the protection target, the structural type of the sound barrier, and the end extension, and cannot comprehensively obtain the optimal design solution from the perspectives of economy, structural safety, and noise reduction effect. Summary of the invention

[0005] In view of this, the present invention aims to overcome the shortcomings of the above-mentioned problems in the prior art and proposes a high-speed rail transit sound barrier design method, which can comprehensively consider the technical conditions of the high-speed rail transit line, the noise reduction requirements of emission noise, the structural type of the sound barrier, the height of the upright sound barrier, the enclosed area of ​​the closed sound barrier, the extension amount of the sound barrier end, etc., to achieve precise design of the sound barrier, so as to comprehensively optimize the noise reduction efficiency, economy, and structural safety of the designed sound barrier.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A first aspect of the present invention provides a method for designing a high-speed rail transit sound barrier, comprising the following steps:

[0008] S1: The noise generated by the operation of high-speed rail transit vehicles is equivalent to the combined sound sources in different areas as equivalent sound sources;

[0009] S2: Taking the equivalent sound source as a fixed sound source, converting the time interval of train movement into the distance interval of measuring points along the length of the line, and obtaining the infinite length sound barrier structure type, vertical sound barrier height or closed sound barrier enclosed area that meets the emission noise standard through iterative calculation;

[0010] S3: Taking the equivalent sound source as a mobile sound source, the sound barrier structure type, size and end extension that meet the emission noise standards are obtained through iterative calculation.

[0011] Furthermore, the step S1 specifically includes:

[0012] Based on sound source identification, scaled model wind tunnel tests or reliable numerical calculations, the sound power levels of the head car area, tail car area and the entire vehicle surface under high-speed operation of the designed line rail transit vehicles are obtained. According to the proportion of sound energy in different areas, the sound power levels of all areas are further divided into combined equivalent sound sources of point sound sources, line sound sources and surface sound sources.

[0013] Furthermore, the step S2 specifically includes:

[0014] The equivalent sound source determined in step S1 is used as a fixed sound source, and the time interval of the moving sound source is converted into the same distance measuring points with the same interval along the length direction of the line, and the moving speed of the sound source is multiplied by the adopted passing sound level time interval as the distance interval of the measuring points along the length direction of the rail transit line;

[0015] Calculate the equivalent sound level time history curve when the sound source attenuates to the measuring point when a train passes through the line with sound barriers, take the time length of the peak of the time history curve as the train passing period, and calculate the exposure sound level of the train passing during this period;

[0016] Based on the train traffic and day-night traffic ratio provided by the design, calculate the daytime equivalent sound level and nighttime equivalent sound level at the measuring points 30m from the centerline of the outer rail and 1.2m above the ground respectively;

[0017] Compare the daytime equivalent sound level and nighttime equivalent sound level with the standard requirements respectively as the judgment conditions for meeting the design requirements. Determine the structural type and size of the acoustic design of the sound barrier by calculating the daytime and nighttime equivalent sound levels after setting up an infinitely long sound barrier.

[0018] The vertical sound barrier is based on a 2.3m high vertical sound barrier as the basic working condition for iterative calculation. The vertical sound barrier height is incremented by 0.5m, and the vertical sound barrier height that meets the noise emission standards is calculated through iterative calculation.

[0019] The closed sound barrier is based on a 4.8m high vertical sound barrier with an equivalent height of a single-sided closed sound barrier. The closed area of ​​the closed sound barrier that meets the noise emission standards is calculated through iterative calculation, with L being the dimension of the sound barrier unit along the length of the line.

[0020] Furthermore, the step S3 specifically includes:

[0021] The structure type of the sound barrier that meets the emission standards and the height of the upright sound barrier or the enclosed area of ​​the enclosed sound barrier determined in step S2 are used as the definite structure and size of the sound barrier of limited length;

[0022] The equivalent sound source determined in step S1 is defined as a mobile sound source, the moving speed of the sound source is the high-speed running speed of the rail transit vehicle, the extension amount of the sound barrier end is 50m as the benchmark, and 10m is the extension amount increment of the sound barrier end. The equivalent sound level time history curve when the train passes through the sound barrier line is calculated, and the peak intercept time of the time history curve is taken as the train passing period, and the train passing exposure sound level SEL2 during this period is calculated;

[0023] Based on the train traffic and day-night traffic ratio provided by the design, calculate the daytime equivalent sound level and nighttime equivalent sound level at the measuring points 30m from the centerline of the outer rail and 1.2m above the ground respectively.

[0024] The daytime equivalent sound level and nighttime equivalent sound level are compared with the standard requirements respectively, and the end extension amount of the sound barrier with clear structure and size that meets the noise emission standards is determined through iterative calculation.

[0025] Furthermore, the upright sound barrier is a cantilever structure with a maximum setting height of 4.3m. If the calculation result of the 4.3m high upright sound barrier still does not meet the standard, a closed sound barrier with a steel structure spanning the rail transit line will be used.

[0026] A second aspect of the present invention provides a high-speed rail transit sound barrier, which is designed using the above-mentioned high-speed rail transit sound barrier design method.

[0027] Compared with the prior art, the high-speed rail transit sound barrier design method described in the present invention has the following advantages:

[0028] The present invention firstly accurately equates the noise generated by the operation of ultra-high-speed rail transit vehicles to combined sound sources in different areas through actual measurement, model test or reliable calculation, etc., uses the determined combined sound source as a fixed sound source, converts the time interval of train movement into the distance interval of measuring points along the length direction of the line, and iteratively calculates the infinitely long sound barrier structure type, the height of the upright sound barrier or the closed area of ​​the closed sound barrier that meets the emission noise standard, and then uses the combined sound source as a mobile sound source, and iteratively calculates the extension of the end of the sound barrier with a determined structure type and size. This design method comprehensively obtains the optimal design scheme of the sound barrier from the aspects of economy, structural safety and noise reduction effect, based on the sound characteristics of high-speed rail transit, improves the rationality of the design, and is more in line with the noise reduction design requirements of high-speed rail transit. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 is a flow chart of the method of the present invention;

[0031] Figure 2 The general structural type and height iterative increment diagram of the baseline working condition of the vertical sound barrier;

[0032] Figure 3 In order to treat the sound source as a fixed sound source, the train movement time interval is converted into a schematic diagram of the distance interval of the measuring points;

[0033] Figure 4 The general structural type and iterative increment diagram of the enclosed area benchmark working condition of the enclosed sound barrier;

[0034] Figure 5 The standard design and incremental diagram of the sound barrier end extension;

[0035] Figure 6 is the equivalent sound source of Example 1;

[0036] Figure 7 For the sound barrier of Example 1, an infinitely long 2.3m high upright sound barrier is set, and the train passes the equivalent sound level time history curve and interception Dt1 schematic diagram at the measuring point 30m from the center line of the outer rail and 1.2m above the ground;

[0037] Figure 8 For Example 1, the sound barrier is set with different end extensions, and the equivalent sound level time-history curve and intercepted Dt2 schematic diagram of the train passing the measuring point 30m from the outer rail centerline and 1.2m above the ground. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] Example 1: See Figure 1 The high-speed rail transit sound barrier design method of the present invention mainly includes: (S1) high-speed rail transit vehicle operation sound source equivalence; (S2) defining a stationary sound source, and iteratively calculating to determine the infinitely long sound barrier structure type, the vertical sound barrier height or the closed area of ​​the closed sound barrier that meets the noise reduction requirements; (S3) defining a moving sound source, and iteratively calculating the extension of the sound barrier end with a clear structural type and size that meets the noise reduction requirements.

[0043] S1: The sound power levels of the head vehicle area, the tail vehicle area and the whole vehicle surface under the high-speed running state of the designed line rail transit vehicle are obtained by sound source identification, scaled model wind tunnel test or reliable numerical calculation. According to the sound energy proportion of different areas, the sound power levels of all areas are further divided into combined equivalent sound sources of point sound sources, line sound sources and surface sound sources as input items of the acoustic design method of the sound barrier of the present invention;

[0044] See also Figure 2 , combined with the technical conditions of the rail transit line section such as the track surface height, vehicle passing speed, line structure type, etc., a certain equivalent sound source is used as a fixed sound source, and the moving sound source time interval (DT) is converted into measuring points at the same distance from the center line of the outer rail of the line with the same interval (DL) along the length of the line. The sound source moving speed (V) is multiplied by the adopted passing sound level time interval as the distance interval of the measuring points along the length of the rail transit line. The relationship between the time interval and the distance interval of the measuring points is shown in Formula 1.

[0045] DT=DL / V Formula 1

[0046] Calculate the equivalent sound level time history curve when the sound source attenuates to the measuring point when a train passes through the sound barrier line, and take the peak value L of the time history curve as the value. max1 -20dB(A) interception time is the train passing period Dt1(T2-T1), L A (t1) is the equivalent sound level at the measuring point at each time, and the train passing exposure sound level SEL1 during this period is calculated as shown in Formula 2.

[0047]

[0048] Based on the number of train traffic logarithms (a) and the ratio of daytime and nighttime traffic (θ) provided by the design, the daytime equivalent sound level L at the measuring points 30m from the centerline of the outer rail and 1.2m above the ground is calculated respectively. Aeq,昼1 , night equivalent sound level L Aeq,夜1 , as shown in Formula 3 and Formula 4 respectively.

[0049]

[0050]

[0051] L Aeq,昼1 , L Aeq,夜1 The daytime and nighttime equivalent sound levels of the sound barrier with infinite length are calculated by referring to the standard requirements of 70dB(A) and 60dB(A) in Railway Boundary Noise Limits and Their Measurement Methods (GB12525-90) as the criteria for meeting the design requirements. The structural type and size of the acoustic design of the sound barrier are determined by calculating the day and night equivalent sound levels after setting up an infinite length sound barrier.

[0052] See also Figure 3The vertical sound barrier takes a 2.3m high vertical sound barrier as the basic working condition for iterative calculation. The height of the vertical sound barrier is increased in increments of 0.5m, and the height of the vertical sound barrier that meets the noise emission standards is calculated through iterative calculation. The vertical sound barrier is a cantilever structure. Based on structural reliability considerations, the maximum setting height is 4.3m. If the calculation result of the 4.3m high vertical sound barrier still does not meet the standard, a closed sound barrier with a steel structure spanning the rail transit line must be used.

[0053] See also Figure 4 The closed sound barrier is based on a single-sided closed sound barrier with an equivalent height of 4.8m high vertical sound barrier. The closed area interval along the closed sound barrier section is 0.5m*L (L is the dimension of the sound barrier unit along the length of the line). The closed area of ​​the closed sound barrier that meets the noise emission standards is calculated through iterative calculation.

[0054] See also Figure 5 The determined infinite length sound barrier structure type that meets the emission standards, the height of the upright sound barrier or the enclosed area of ​​the closed sound barrier are used as the clear structure and size of the finite length sound barrier. The determined equivalent sound source is defined as a mobile sound source. The moving speed of the sound source is the high-speed running speed of the rail transit vehicle (V). The extension of the end of the sound barrier is 50m as the basic working condition for iterative calculation, and 10m is the increment of the extension of the end of the sound barrier.

[0055] Calculate the equivalent sound level time history curve when the sound source attenuates to the measuring point when a train passes through the sound barrier line, and take the peak value L of the time history curve as the value. max2 The -20dB(A) interception time is the train passing period Dt2(T4-T3), and the train passing exposure sound level SEL2 in this period is calculated. A (t2) is the equivalent sound level at the measuring point at each moment, as shown in Formula 5.

[0056]

[0057] Based on the train flow (a) and day-night flow ratio (θ) provided by the design, calculate the daytime equivalent sound level L at the measuring points 30m from the centerline of the outer rail and 1.2m above the ground respectively. Aeq,昼2 , night equivalent sound level L Aeq,夜2 , as shown in Formula 6 and Formula 7 respectively.

[0058]

[0059] The two calculation results are compared with the standard requirements of "Railway Boundary Noise Limits and Their Measurement Methods" (GB12525-90) of 70dB(A) during the day and 60dB(A) at night, and the end extension of the sound barrier with clear structure and size that meets the noise emission standards is determined through iterative calculation.

[0060] The high-speed rail transit acoustic precision design method of the present invention is described in detail below with reference to specific embodiments.

[0061] The high-speed maglev line is designed to have a speed of 450km / h, a track height of 10m in the noise protection section, a bridge line type, 167 pairs of trains per day, and a day-night train ratio of 8:1.

[0062] (1) See Figure 6 Through the sound source identification test of the operating maglev train, the individual sound sources on the surface of the car body and different surrounding areas when the high-speed maglev train passes at high speed are located. By processing the test results, the sound sources in similar areas are merged and equivalent to line sound sources or point sound sources according to the sound source characteristics. The sound source generated by the 3-car high-speed maglev running at a speed of 450km / h is equivalent to 5 parts of sound sources in the area near the car body. The type, size (mainly for line sound sources), number and sound power level of the sound source are shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] (2) Using the equivalent sound source in Table 1 as the fixed sound source, the train moving time interval DT is 0.008s. The time interval is converted into measuring points at the same interval along the length of the line, 30m away from the center line of the outer rail and 1.2m above the ground. According to Formula 1, the distance DL between adjacent measuring points is 1m.

[0067] (3-1) According to the track height of 10m and the line type of bridge, after setting up an infinite length 2.3m high vertical sound barrier, the equivalent sound level at all measuring points after the equivalent sound source attenuates in Table 1 is calculated. According to the conversion relationship between the measuring point interval DL and the test piece interval DT, the passing sound level of the measuring points at different positions is converted into the equivalent sound level of a single measuring point at different times, and the time history curve of the sound source attenuating to the equivalent sound level at the measuring point when the high-speed maglev train passes at a speed of 450km / h is obtained.

[0068] (3-2) See Figure 7 , from the equivalent sound level time history curve, we can get, L max1 is 92.2dB(A), then L max1 -20dB(A) or 72.2dB(A) is taken as the reference value. The time curve is intercepted to determine the train passing period T1~T2. According to Formula 2, the high-speed maglev passing period SEL1 is calculated to be 92.5dB(A).

[0069] (3-3) With a train flow log of 167 and a day-night flow ratio of 8:1, after setting up an infinitely long 2.3m high vertical sound barrier, the daytime equivalent sound level L at the measuring point 30m from the centerline of the outer rail and 1.2m above the ground is calculated according to Formula 3 and Formula 4 respectively. Aeq,昼1 The equivalent sound level at night is 69.7dB(A). Aeq,夜1 It is 63.6dB(A).

[0070] (3-4) According to the standard requirements of "Railway Boundary Noise Limits and Their Measurement Methods" (GB12525-90), which are 70dB(A) during the day and 60dB(A) at night, after installing an infinitely long 2.3m high vertical sound barrier, the technical conditions of this embodiment meet the standard requirements during the day and exceed the standard requirements by 3.6dB(A) at night.

[0071] (3-5) Set up an infinitely long 2.8m high (the 2.3m high vertical sound barrier has a superimposed height increment of 0.5m) vertical sound barrier, repeat steps (3-1) to (3-4), and calculate the daytime equivalent sound level L at the measuring point 30m away from the centerline of the outer rail and 1.2m above the ground. Aeq,昼1 The equivalent sound level at night is 69.4dB(A). Aeq,夜1 It is 63.4dB(A), which meets the standard requirements during the day and exceeds the standard requirements by 3.4dB(A) at night.

[0072] (3-6) Set up an infinitely long 3.3m high (the 2.8m high vertical sound barrier has a superimposed height increment of 0.5m) vertical sound barrier, repeat steps (3-1) to (3-4), and calculate the daytime equivalent sound level L at the measuring point 30m away from the centerline of the outer rail and 1.2m above the ground. Aeq,昼1 The equivalent sound level at night is 67.1dB(A). Aeq,夜1 It is 61.1dB(A), which meets the standard requirements during the day and exceeds the standard requirements by 1.1dB(A) at night.

[0073] (3-7) Set up an infinitely long 3.8m high (3.3m high vertical sound barrier with a superimposed height increment of 0.5m) vertical sound barrier, repeat steps (3-1) to (3-4), and calculate the daytime equivalent sound level L at the measuring point 30m away from the centerline of the outer rail and 1.2m above the ground. Aeq,昼1 The equivalent sound level at night is 66.1dB(A). Aeq,夜1 It is 60.1dB(A), which meets the standard requirements during the day and exceeds the standard requirements by 0.1dB(A) at night.

[0074] (3-8) Set up an infinitely long 4.3m high (3.8m high vertical sound barrier with a superimposed height increment of 0.5m) vertical sound barrier, repeat steps (3-1) to (3-4), and calculate the daytime equivalent sound level L at the measuring point 30m away from the centerline of the outer rail and 1.2m above the ground.Aeq,昼1 The equivalent sound level at night is 64.2dB(A). Aeq,夜1 It is 58.2dB(A), which meets the standard requirements both during the day and at night.

[0075] (3-9) If an infinitely long 4.3m high vertical sound barrier is set, and the day and night equivalent sound levels at the measuring point 30m away from the center line of the outer rail and 1.2m above the ground do not meet the standard requirements, a closed sound barrier needs to be set. The closed sound barrier is based on the equivalent height of a 4.8m high vertical sound barrier on the closed area of ​​a single-sided closed sound barrier, and the closed area interval is 0.5m*L (L is the size of the sound barrier unit along the length of the line) along the cross section of the closed sound barrier. By repeating steps (3-1) to (3-4) iteratively calculate the closed area of ​​the closed sound barrier that meets the noise emission standards.

[0076] (4-1) The equivalent sound source determined in step (1) is defined as a moving sound source, and the moving speed of the sound source is 450 km / h.

[0077] (4-2) Based on the track surface height of 10m and the line type of bridge, after calculating the setting of a 4.3m high upright sound barrier with an end extension of 50m, the equivalent sound level at the measuring point 50m away from the end of the sound barrier, 30m away from the center line of the outer rail, and 1.2m above the ground is calculated according to the specific location of the sound source at each moment, and the equivalent sound level time history curve at the measuring point is obtained.

[0078] (4-3) See Figure 8 , from the equivalent sound level time history curve, we can get, L max2 is 86.4dB(A), then L max2 -20dB(A) or 66.4dB(A) is taken as the reference value. The time curve is intercepted to determine the train passing period T3~T4. According to Formula 5, the high-speed maglev passing period SEL2 is calculated to be 88.4dB(A).

[0079] (4-4) With a train flow logarithm of 167 and a day-night flow ratio of 8:1, a 4.3m high vertical sound barrier with an end extension of 50m is set. According to Formula 6 and Formula 7, the daytime equivalent sound level L at the measuring point 50m from the end of the sound barrier, 30m from the center line of the outer rail, and 1.2m above the ground is calculated respectively. Aeq,昼1 The equivalent sound level at night is 65.5dB(A). Aeq,夜1 It is 59.5dB(A).

[0080] (4-5) According to the standard requirements of "Railway Boundary Noise Limits and Their Measurement Methods" (GB12525-90), which are 70dB(A) during the day and 60dB(A) at night, a 4.3m high vertical sound barrier with an end extension of 50m is installed. Under the technical conditions of this embodiment, the standard requirements are met both during the day and at night.

[0081] (5) For the high-speed maglev line with a design speed of 450 km / h, the track height of the noise protection section is 10 m, the line type is a bridge, there are 167 pairs of trains per day, and the day-night train ratio is 8:1. The design requires a 4.3 m high vertical sound barrier with an end extension of 50 m to meet the requirements of the Railway Boundary Noise Limits and Their Measurement Methods (GB12525-90) standard.

[0082] Example 2: The present invention provides a high-speed rail transit sound barrier, which is designed using the above-mentioned high-speed rail transit sound barrier design method.

[0083] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for designing a high-speed rail transit sound barrier, characterized in that: The steps include: S1: The noise generated by the operation of high-speed rail transit vehicles is equivalent to the combined sound sources in different areas as equivalent sound sources; S2: Taking the equivalent sound source as a fixed sound source, converting the time interval of train movement into the distance interval of measuring points along the length of the line, and obtaining the infinite length sound barrier structure type, vertical sound barrier height or closed sound barrier enclosed area that meets the emission noise standard through iterative calculation; S3: Taking the equivalent sound source as a mobile sound source, the sound barrier structure type, size and end extension that meet the emission noise standards are obtained through iterative calculation.

2. A high-speed rail transit sound barrier design method according to claim 1, characterized in that: The step S1 specifically includes: Based on sound source identification, scaled model wind tunnel tests or reliable numerical calculations, the sound power levels of the head car area, tail car area and the entire vehicle surface under high-speed operation of the designed line rail transit vehicles are obtained. According to the proportion of sound energy in different areas, the sound power levels of all areas are further divided into combined equivalent sound sources of point sound sources, line sound sources and surface sound sources.

3. A high-speed rail transit sound barrier design method according to claim 1, characterized in that: The step S2 specifically includes: The equivalent sound source determined in step S1 is used as a fixed sound source, and the time interval of the moving sound source is converted into the same distance measuring points with the same interval along the length direction of the line, and the moving speed of the sound source is multiplied by the adopted passing sound level time interval as the distance interval of the measuring points along the length direction of the rail transit line; Calculate the equivalent sound level time history curve when the sound source attenuates to the measuring point when a train passes through the line with sound barriers, take the time length of the peak of the time history curve as the train passing period, and calculate the exposure sound level of the train passing during this period; Based on the train traffic and day-night traffic ratio provided by the design, calculate the daytime equivalent sound level and nighttime equivalent sound level at the measuring points 30m from the centerline of the outer rail and 1.2m above the ground respectively; Compare the daytime equivalent sound level and nighttime equivalent sound level with the standard requirements respectively as the judgment conditions for meeting the design requirements. Determine the structural type and size of the acoustic design of the sound barrier by calculating the daytime and nighttime equivalent sound levels after setting up an infinitely long sound barrier. The vertical sound barrier is based on a 2.3m high vertical sound barrier as the basic working condition for iterative calculation. The vertical sound barrier height is incremented by 0.5m, and the vertical sound barrier height that meets the noise emission standards is calculated through iterative calculation. The closed sound barrier is based on a 4.8m high vertical sound barrier with an equivalent height of a single-sided closed sound barrier. The closed area of ​​the closed sound barrier that meets the noise emission standards is calculated through iterative calculation, with L being the dimension of the sound barrier unit along the length of the line.

4. A high-speed rail transit sound barrier design method according to claim 1, characterized in that: The step S3 specifically includes: The structure type of the sound barrier that meets the emission standards and the height of the upright sound barrier or the enclosed area of ​​the enclosed sound barrier determined in step S2 are used as the definite structure and size of the sound barrier of limited length; The equivalent sound source determined in step S1 is defined as a mobile sound source, the moving speed of the sound source is the high-speed running speed of the rail transit vehicle, the extension amount of the sound barrier end is 50m as the benchmark, and 10m is the extension amount increment of the sound barrier end. The equivalent sound level time history curve when the train passes through the sound barrier line is calculated, and the peak intercept time of the time history curve is taken as the train passing period, and the train passing exposure sound level SEL2 during this period is calculated; Based on the train traffic and day-night traffic ratio provided by the design, calculate the daytime equivalent sound level and nighttime equivalent sound level at the measuring points 30m from the centerline of the outer rail and 1.2m above the ground respectively. The daytime equivalent sound level and nighttime equivalent sound level are compared with the standard requirements respectively, and the end extension amount of the sound barrier with clear structure and size that meets the noise emission standards is determined through iterative calculation.

5. A high-speed rail transit sound barrier design method according to claim 3, characterized in that: The vertical sound barrier is a cantilever structure with a maximum setting height of 4.3m. If the calculation result of the 4.3m high vertical sound barrier still does not meet the standard, a closed sound barrier with a steel structure spanning the rail transit line will be used.

6. A high-speed rail transit sound barrier designed by the high-speed rail transit sound barrier design method described in any one of claims 1 to 5.

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