Method and system for calculating passing noise of urban rail transit train

Abstract

The invention discloses a method and a system for calculating passing noise of an urban rail transit train. The method comprises the following steps: selecting a typical section in a noise calculation prediction area; setting a plurality of prediction points in the section, and respectively collecting noise calculation parameters at the plurality of prediction points; substituting the noise calculation parameters corresponding to the plurality of prediction points into the constructed train passing noise calculation model, and fitting the train passing noise calculation model to obtain a fitted calculation model; and substituting the working condition parameters of a to-be-measured prediction point in the region into the fitted calculation model, and calculating to obtain a noise value of the to-be-measured prediction point. Wherein the regional range can be a city or one or more urban rail transit line regions with similar conditions, and the method can simplify the process of calculating and predicting the train passing noise in the region on the premise of ensuring certain calculation precision.

Description

Technical Field

[0001] The present invention relates to the field of rail transit, and in particular to a method and system for calculating the passing noise of urban rail transit trains. Background Art

[0002] Environmental noise along rail transit lines is one of the main pollution factors of rail transit. Before building ground tracks or developing and constructing around tracks, it is necessary to predict ground track noise pollution.

[0003] At present, the commonly used prediction method refers to the urban rail transit prediction model in my country's "Technical Guidelines for Environmental Impact Assessment of Acoustic Environment" (HJ 2.4-2021). The calculation of this prediction model comprehensively considers correction items, mainly including speed, vertical directivity, line and track structure, geometric divergence loss, atmospheric absorption, ground effect, sound barrier, building complex, reflection and other correction items, but the prediction calculation process is relatively complex and highly professional. For relevant non-professional competent departments and surrounding residents who want to understand the possible rail noise conditions at their location, the learning process of using the calculation method in the guidelines is cumbersome and the calculation time is long.

[0004] Therefore, a new method and system for calculating the passing noise of urban rail transit trains is needed, which can simplify the calculation process while ensuring a certain calculation accuracy. Summary of the invention

[0005] In view of this, an object of the present invention is to overcome the defects in the prior art and provide a method and system for calculating the passing noise of urban rail transit trains, which can simplify the calculation process while ensuring a certain calculation accuracy.

[0006] The method for calculating the passing noise of urban rail transit trains of the present invention comprises:

[0007] Select a typical section within the noise calculation prediction area; set a number of prediction points within the typical section, and collect noise calculation parameters at the several prediction points respectively;

[0008] Substituting the noise calculation parameters corresponding to the plurality of prediction points into the constructed train passing noise calculation model, fitting the train passing noise calculation model, and obtaining a fitted calculation model;

[0009] The operating parameters at the predicted point to be tested are substituted into the fitted calculation model to calculate the noise value at the predicted point to be tested.

[0010] Furthermore, the noise calculation parameters include the equivalent continuous A sound level at the prediction point during the train passing period, the noise source strength, the horizontal distance between the prediction point and the center line of the near track, and the height difference between the prediction point and the track surface.

[0011] Furthermore, the train passing noise calculation model is determined according to the following formula:

[0012]

[0013] Among them, L Aeq,Tp is the equivalent continuous A sound level at the predicted point during the train passing period; L p0 is the noise source strength; D is the horizontal distance between the prediction point and the center line of the near track; H is the height difference between the prediction point and the track surface; a, b, c are all unknown coefficients.

[0014] Furthermore, the train passing noise calculation model is fitted, specifically including:

[0015] Several groups of noise calculation parameters are input into numerical analysis software, and the train passing noise calculation model is fitted through the numerical analysis software to obtain the unknown coefficients in the train passing noise calculation model.

[0016] Further, the operating condition parameters include the noise source intensity, the horizontal distance between the prediction point and the near-track centerline, and the height difference between the prediction point and the track surface;

[0017] The noise value is the equivalent continuous A sound level at the predicted point during the train passing period.

[0018] A system for calculating the passing noise of urban rail transit trains, comprising an information collection unit, a model building unit and a noise calculation unit;

[0019] The information collection unit is used to select a typical section in the noise calculation prediction area; set a number of prediction points in the typical section, and collect noise calculation parameters at the number of prediction points respectively;

[0020] The model building unit is used to substitute the noise calculation parameters corresponding to the plurality of prediction points into the constructed train passing noise calculation model, fit the train passing noise calculation model, and obtain a fitted calculation model;

[0021] The noise calculation unit is used to substitute the operating condition parameters at the predicted point to be measured into the fitted calculation model to calculate the noise value at the predicted point to be measured.

[0022] Furthermore, the noise calculation parameters include the equivalent continuous A sound level at the prediction point during the train passing period, the noise source strength, the horizontal distance between the prediction point and the center line of the near track, and the height difference between the prediction point and the track surface.

[0023] Furthermore, the train passing noise calculation model is determined according to the following formula:

[0024]

[0025] Among them, L Aeq,Tpis the equivalent continuous A sound level at the predicted point during the train passing period; L p0 is the noise source strength; D is the horizontal distance between the prediction point and the center line of the near track; H is the height difference between the prediction point and the track surface; a, b, c are all unknown coefficients.

[0026] Furthermore, the train passing noise calculation model is fitted, specifically including:

[0027] Several groups of noise calculation parameters are input into numerical analysis software, and the train passing noise calculation model is fitted through the numerical analysis software to obtain the unknown coefficients in the train passing noise calculation model.

[0028] Further, the operating condition parameters include the noise source intensity, the horizontal distance between the prediction point and the near-track centerline, and the height difference between the prediction point and the track surface;

[0029] The noise value is the equivalent continuous A sound level at the predicted point during the train passing period.

[0030] The beneficial effects of the present invention are as follows: a method and system for calculating the passing noise of urban rail transit trains disclosed in the present invention can accurately calculate the noise at a prediction point by using only the horizontal distance from the prediction point to the target track and the height difference variables when providing a noise source intensity value; there are no more professional calculation parameters, which simplifies the prediction calculation process, and uses conventional parameter calculations that the public can understand, so that non-professionals can also quickly predict the track noise value at their location. While simplifying the algorithm, a certain calculation accuracy can be guaranteed, and the noise value and noise reduction effect after the installation of a fully enclosed sound barrier can also be calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0032] Figure 1 It is a schematic diagram of the calculation method flow of the present invention;

[0033] Figure 2 This is a schematic diagram of the prediction point arrangement of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings, as shown in the drawings:

[0035] This embodiment discloses a method for calculating the passing noise of urban rail transit trains, comprising the following steps:

[0036] Select a typical section within the noise calculation prediction area; set a number of prediction points within the typical section, and collect noise calculation parameters at the prediction points; the prediction area can be a city, or one or more urban rail transit lines with similar conditions; select a typical section within the prediction area, a typical section: a section that is convenient for point distribution testing, and the measurable attenuation distance is not less than 100m;

[0037] Substituting the noise calculation parameters corresponding to the plurality of prediction points into the constructed train passing noise calculation model, fitting the train passing noise calculation model, and obtaining a fitted calculation model;

[0038] The operating parameters at the predicted point to be tested are substituted into the fitted calculation model to calculate the noise value at the predicted point to be tested.

[0039] In this embodiment, a prediction area is selected in advance, and typical sections under various working conditions are selected in the prediction area, such as a case of no sound barrier and a case of a fully enclosed sound barrier. Rail transit has two different running tracks. In the case of no sound barrier, the near-track and far-track conditions can be considered for the same prediction point. In the case of a fully enclosed sound barrier, similarly, the near-track and far-track conditions can be considered for the same prediction point.

[0040] In the absence of a sound barrier, the prediction point can be either above or below the track, so the height difference H between the prediction point and the track surface ranges from -20≤H≤100 (in meters); in the case of a fully enclosed sound barrier, the prediction point can also be either above or below the track, so the height difference H between the prediction point and the track surface ranges from -20≤H≤100 (in meters). In addition, in order to obtain enough noise calculation parameters under various working conditions, the horizontal distance D between the prediction point and the near-track centerline ranges from 10≤D≤200 (in meters).

[0041] Specifically, noise attenuation tests can be conducted on cities or several lines with the same noise characteristics under different D and H values ​​without sound barriers or fully enclosed sound barriers. For example, vertical section tests can be conducted under two or three different D values, so that multiple sets of noise calculation parameters can be collected. Among them, noise attenuation testing is a process used to measure and evaluate the reduction of noise levels in a system or environment as distance or other parameters change.

[0042] For the equivalent continuous A sound level L at the predicted point during the train passing period Aeq,Tp The L can be collected by using a frequency-weighted sound level meter that meets the relevant definition in GB / T3785.1 to measure the equivalent continuous A sound level during the train passing period at the prediction point, and the average value of the five passing measurement data is taken as L Aeq,Tp .

[0043] like Figure 2 As shown, for the noise source strength L at the same prediction point p0 If the data is collected under the condition of near-orbit, the noise source strength L p0 is the near-track noise source strength, which is taken as the equivalent continuous A sound level during a single train passing period at a distance of 7.5 m from the near-track centerline and 5 m above the track surface; if data is collected under the far-track condition, the noise source strength L at this time p0 is the far-track noise source strength, which is taken as the equivalent continuous A-level of a single train passing period at 7.5m from the centerline of the near-track + the distance between the near-track and the far-track, and 5m above the track surface; the measurement of the equivalent continuous A-level of a single train passing period is consistent with the above L Aeq,Tp The measurement principle is the same and will not be described here. Alternatively, the noise source strength L p0 It can be directly obtained by referring to relevant environmental assessment documents or design parameters without measurement. The train passing period refers to the time period from the front to the rear of the train passing directly in front of the sound level meter.

[0044] Through the above processing or setting, for a prediction point, a set of noise calculation parameters (L Aeq,Tp , L p0 , D, H); then multiple prediction points correspond to multiple sets of noise calculation parameters.

[0045] In this embodiment, the collected multiple groups of noise calculation parameters are substituted into the train passing noise calculation model:

[0046]

[0047] Among them, L Aeq,Tp is the equivalent continuous A sound level at the predicted point during the train passing period; L p0 is the noise source strength; D is the horizontal distance between the prediction point and the center line of the near track; H is the height difference between the prediction point and the track surface; a, b, c are all unknown coefficients.

[0048] Using numerical analysis software such as Matlab and 1stOpt, the train passing noise calculation model formula framework is applied to fit the a, b, and c series values ​​applicable to a region or lines with the same noise, vehicle type, and line condition characteristics. The obtained a, b, and c values ​​are substituted into the train passing noise calculation model to obtain the fitted calculation model:

[0049]

[0050] Among them, a 0 , b 0 、c 0 All are known coefficients.

[0051] In this embodiment, the working condition parameters at the predicted point to be tested: noise source intensity, horizontal distance between the predicted point and the near-track centerline, and height difference between the predicted point and the track surface are substituted into the fitted calculation model to calculate the noise value at the predicted point to be tested. The noise value is the equivalent continuous A sound level L at the predicted point during the train passing period. Aeq,Tp That is, when the noise source strength at the actual predicted point to be tested is known, the noise value L can be directly calculated by substituting the horizontal distance D between the predicted point and the near-track centerline and the height difference H between the predicted point and the track surface into the fitted calculation model. Aeq,Tp .

[0052] Furthermore, for the same prediction point, the noise value L in the case of no sound barrier and the case of fully enclosed sound barrier can be calculated respectively: 1 Aeq,Tp And the noise value L under the fully enclosed sound barrier 2 Aeq,Tp ; Noise value L 1 Aeq,Tp Subtract the noise value L 2 Aeq,Tp The result value can be used as the noise reduction effect value of the sound barrier, and can be used to evaluate the noise reduction effect after installing a fully enclosed sound barrier. This fills the gap in the calculation method for predicting the noise reduction effect of a fully enclosed sound barrier based on relative position relationships. The authenticity of this noise reduction effect is higher than the one-size-fits-all noise reduction prediction of a fully enclosed sound barrier in traditional environmental impact assessments (usually taking a unified value of 16-25dB(A)).

[0053] The present invention also relates to a calculation system for urban rail transit train passing noise, the calculation system corresponds to the calculation method of the above embodiment, and can be understood as a system for implementing the above calculation method, the system includes an information collection unit, a model building unit and a noise calculation unit;

[0054] The information collection unit is used to select a typical section in the noise calculation prediction area; set a number of prediction points in the typical section, and collect noise calculation parameters at the number of prediction points respectively;

[0055] The model building unit is used to substitute the noise calculation parameters corresponding to the plurality of prediction points into the constructed train passing noise calculation model, fit the train passing noise calculation model, and obtain a fitted calculation model;

[0056] The noise calculation unit is used to substitute the operating condition parameters at the predicted point to be measured into the fitted calculation model to calculate the noise value at the predicted point to be measured.

[0057] It has been verified that using the calculation model formula fitted by the present invention, the calculation error of any prediction point does not exceed 3dB(A), the overall error is 0.3dB(A) on average, and the prediction result is accurate.

[0058] Compared with the rigorous train passing noise prediction model in the "Technical Guidelines for Environmental Impact Assessment of Acoustic Environment" HJ2.4-2021, the calculation of the present invention is simpler and does not require many correction items. In the case of active strength, only the height difference and horizontal distance of the track are considered to accurately predict the train passing noise in the noise propagation path.

[0059] The calculation method of the present invention is simple and does not require professional basic acoustic knowledge. It can be used for auxiliary calculation of noise control distance in rail transit peripheral development planning, and for spontaneous evaluation of noise levels by ordinary people when buying houses. The present invention is based on fitting of actual test data, and the calculation distinguishes between above and below the rail surface. For the noise under the beam affected by secondary structural noise, the prediction is more accurate.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for calculating the passing noise of urban rail transit trains, characterized in that: include: Select typical sections within the noise calculation prediction area; Several prediction points are set in the typical section, and noise calculation parameters are collected at the several prediction points respectively; Substituting the noise calculation parameters corresponding to the plurality of measuring points into the constructed train passing noise calculation model, fitting the train passing noise calculation model, and obtaining a fitted calculation model; The operating parameters at the predicted point to be tested are substituted into the fitted calculation model to calculate the noise value at the predicted point to be tested.

2. The method for calculating the passing noise of urban rail transit trains according to claim 1, characterized in that: The noise calculation parameters include the equivalent continuous A sound level at the predicted point during the train passing period, the noise source strength, the horizontal distance between the predicted point and the center line of the near track, and the height difference between the predicted point and the track surface.

3. The method for calculating the passing noise of urban rail transit trains according to claim 1, characterized in that: The train passing noise calculation model is determined according to the following formula: Among them, L Aeq,Tp is the equivalent continuous A sound level at the predicted point during the train passing period; L p0 is the noise source strength; D is the horizontal distance between the prediction point and the center line of the near track; H is the height difference between the prediction point and the track surface; a, b, c are all unknown coefficients.

4. The method for calculating the passing noise of urban rail transit trains according to claim 3 is characterized in that: Fitting the train passing noise calculation model includes: Several groups of noise calculation parameters are input into numerical analysis software, and the train passing noise calculation model is fitted through the numerical analysis software to obtain the unknown coefficients in the train passing noise calculation model.

5. The method for calculating the passing noise of urban rail transit trains according to claim 1, characterized in that: The working condition parameters include the noise source intensity, the horizontal distance between the prediction point and the near-track centerline, and the height difference between the prediction point and the track surface; The noise value is the equivalent continuous A sound level at the predicted point during the train passing period.

6. A system for calculating the passing noise of urban rail transit trains, characterized in that: It includes an information collection unit, a model building unit and a noise calculation unit; The information collection unit is used to select a typical section in the noise calculation prediction area; set a number of prediction points in the typical section, and collect noise calculation parameters at the number of prediction points respectively; The model building unit is used to substitute the noise calculation parameters corresponding to the plurality of prediction points into the constructed train passing noise calculation model, fit the train passing noise calculation model, and obtain a fitted calculation model; The noise calculation unit is used to substitute the operating condition parameters at the predicted point to be measured into the fitted calculation model to calculate the noise value at the predicted point to be measured.

7. The urban rail transit train passing noise calculation system according to claim 6, characterized in that: The noise calculation parameters include the equivalent continuous A sound level at the predicted point during the train passing period, the noise source strength, the horizontal distance between the predicted point and the center line of the near track, and the height difference between the predicted point and the track surface.

8. The urban rail transit train passing noise calculation system according to claim 6, characterized in that: The train passing noise calculation model is determined according to the following formula: Among them, L Aeq,Tp is the equivalent continuous A sound level at the predicted point during the train passing period; L p0 is the noise source strength; D is the horizontal distance between the prediction point and the center line of the near track; H is the height difference between the prediction point and the track surface; a, b, c are all unknown coefficients.

9. The urban rail transit train passing noise calculation system according to claim 8, characterized in that: Fitting the train passing noise calculation model includes: Several groups of noise calculation parameters are input into numerical analysis software, and the train passing noise calculation model is fitted through the numerical analysis software to obtain the unknown coefficients in the train passing noise calculation model.

10. The urban rail transit train passing noise calculation system according to claim 6, characterized in that: The working condition parameters include the noise source intensity, the horizontal distance between the prediction point and the near-track centerline, and the height difference between the prediction point and the track surface; The noise value is the equivalent continuous A sound level at the predicted point during the train passing period.

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