Simplified prediction method suitable for indoor secondary structure noise caused by urban rail transit underground line

Abstract

The invention discloses a simplified prediction method suitable for indoor secondary structure noise caused by an urban rail transit underground line, and belongs to the technical field of noise vibration engineering, and the method comprises the following steps: (1) determining an underground line train vibration source, namely 16-200Hz vibration acceleration time-frequency domain signals at a tunnel wall; (2) train vibration propagation attenuation is determined, and the specific attenuation amount is determined through calculation; (3) building indoor vibration comprehensive analysis; and (4) secondary structure noise prediction. According to the simplified prediction method suitable for the indoor secondary structure noise caused by the urban rail transit underground line, the simple and convenient indoor secondary structure noise test method is provided on the basis of a train wheel rail vibration generation mechanism of the urban rail transit typical underground line; technical support is provided for secondary structure noise prediction in urban rail transit underground line environmental assessment prediction, and a basis is provided for vibration control measure selection and resident complaint reduction.

Description

Technical Field

[0001] The invention relates to a simplified prediction method for indoor secondary structure noise caused by an underground line of urban rail transit, and belongs to the technical field of noise and vibration engineering. Background Art

[0002] Urban rail transit has been widely used in major urban areas around the world due to its advantages of punctuality, high efficiency and low carbon. In the past two decades, my country's urban rail transit construction has made great progress.

[0003] Urban rail transit is generally built in the city center, and the residential areas along the line are relatively dense. While providing people with travel convenience, the environmental vibration and secondary structure noise generated by the operation of trains often have a significant impact on the environmental quality along the line, especially on the sleeping environment of residents' bedrooms. Therefore, as the scale of urban rail transit continues to grow, the vibration and secondary structure noise caused by the operation of rail transit lines have gradually become a hot issue for environmental complaints. The impact of vibration and secondary structure noise of urban rail transit has become a key concern for residents along the line due to its high departure frequency, long duration, wide impact range, and multiple impact areas.

[0004] In order to solve or reduce rail transit noise, we should start from the early design of the construction project, do a good job in the environmental impact assessment, and predict, evaluate and propose measures for key aspects such as vibration and secondary structure noise, so as to provide effective technical support for subsequent pollution prevention and control and solving residents' complaints.

[0005] The prediction methods for secondary structure noise in existing standards and guidelines are relatively complex. Unlike the acceleration level of 1 to 80 Hz used in environmental vibration prediction, the vibration velocity level used is 16 to 200 Hz, which poses a great challenge to the prediction work.

[0006] In actual work, the environmental protection targets within the evaluation range of the rail transit linear project are highly specific and diverse. For many sensitive points along the rail transit line, the use of analog measurement is theoretically feasible but basically inoperable. Moreover, full-band calculations will bring complexity.

[0007] Therefore, a simplified prediction method for indoor secondary structure noise caused by urban rail transit underground lines is provided to provide technical support for the prediction of secondary structure noise in the environmental impact assessment of urban rail transit underground lines, provide a basis for the selection of vibration control measures and reduce residents' complaints, and avoid the complexity brought by full-band calculations. Summary of the invention

[0008] The purpose of the present invention is to provide a simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines, to provide powerful technical guidance for subsequent urban rail transit secondary structure noise impact assessment, and to avoid the complexity brought by full-band calculations.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines, the steps of which are as follows:

[0011] (1) Determine the underground train vibration source 1, that is, the 16-200 Hz vibration acceleration time-frequency domain signal at the tunnel wall;

[0012] (2) Determine the train vibration propagation attenuation 2, and determine the specific attenuation amount through calculation;

[0013] (3) Comprehensive analysis of indoor vibration of building 3;

[0014] (4) Prediction of secondary structure-borne noise 4 in buildings (40 Hz, 50 Hz, 63 Hz and 80 Hz).

[0015] Preferably, in step (1), the train vibration source 1 has two structural vibrations, one located below and one located vertically on the tunnel wall.

[0016] Preferably, in step (1), the vibration acceleration of the train vibration source 1 on the vertical tunnel wall is usually determined by on-site analog testing or simulation calculation analysis.

[0017] Preferably, in order to predict secondary structural noise, the frequency range of the vibration acceleration of the train vibration source 1 is 16 to 200 Hz, and 1 / 3 octave data within this frequency band can be provided.

[0018] Preferably, in step (2), there are three vibration propagation paths (train vibration propagation attenuation 2) from the train vibration source 1 to the building room 3: one of them is refracted through the interface between the bedrock and the soil layer 2 and passes through the soil layer 2 to enter the soil layer 3, and then reaches the building; the second one passes through the soil layer 2, and after being refracted at the interface between the soil layer 2 and the soil layer 3, passes through the soil layer 3 to reach the building; the third one passes through the soil layer 2 and the soil layer 3, after being reflected on the surface of the soil layer 3, it reaches the building after 3 reflections in the soil layer 3.

[0019] Preferably, in step (3), the building is a three-story structure, the bottom floor of each structure has structural vibration (building ground vibration acceleration), the wall facing the train direction has structural vibration, and the wall of each structure facing the train side forms secondary structural noise.

[0020] Preferably, according to the requirements of HJ453-2018 or other standards and specifications, a series of parameter corrections such as distance and building are performed to obtain the predicted values ​​of the ground vibration acceleration of the three buildings, and the acceleration levels are simultaneously attenuated in equal proportion to give 1 / 3 octave band acceleration levels.

[0021] Preferably, assuming a simple harmonic vibration wave with a frequency of f, a circular frequency of ω=2πf, a vibration velocity amplitude of v0, and a vibration velocity of:

[0022] v=v0e jωt (Formula 1)

[0023] The vibration acceleration is:

[0024] a=jωv0e jωt (Formula 2)

[0025] Maximum 1 / 3 octave band sound pressure level of indoor secondary structure noise:

[0026] L p,i =L Vmid,i -22 = L amid,i -20lg(f)+22 (Formula 3)

[0027] Where: L amid,i - The vertical 1 / 3 octave vibration acceleration level (16-200 Hz) at the center of the indoor floor of the building during the train passing period, with the reference vibration acceleration value of 1×10 -6 m / s, dB;

[0028] i-the i-th 1 / 3 octave band, i=1~12;

[0029] Substitute the acceleration levels corresponding to the four frequency bands of 40Hz, 50Hz, 63Hz and 80Hz into equation 3 and solve to obtain the prediction of the secondary structure noise corresponding to the frequency division. Substitute it into the following equation 4 and solve to obtain the predicted value of the total sound pressure level of the secondary structure noise:

[0030]

[0031] Where: L Aeq,Tp - Maximum equivalent continuous A-level of indoor space of a building during a single train passing period, dB(A);

[0032] C f,i -A-weighted correction value for the ith frequency band, dB.

[0033] Preferably, according to Formula 3, the corresponding relationship between the vibration velocity and the 1 / 3 frequency division data of the vibration acceleration is established through the mathematical relationship between acceleration and velocity. By solving, 4 frequency bands of 40 Hz, 50 Hz, 63 Hz and 80 Hz are obtained, which correspond to the maximum 1 / 3 octave sound pressure level of the indoor secondary structure noise.

[0034] Preferably, according to Formula 4, four frequency bands of 40 Hz, 50 Hz, 63 Hz and 80 Hz are used to solve the maximum 1 / 3 octave sound pressure level of indoor secondary structure noise, and the predicted value of the total sound pressure level of the secondary structure noise is obtained to complete the prediction of the secondary structure noise.

[0035] The simplified prediction method for indoor secondary structure noise caused by the underground line of urban rail transit of the present invention includes parameter quantification of the uncertainty appearing in the environmental impact assessment prediction process and necessary processing of the links that can be simplified in the prediction process. Since the vibration source (vehicle type, line type, track type, wheel-rail condition, tunnel type), propagation path (burial depth, distance), building foundation type, building interior decoration, building layout, etc. will affect the secondary structure noise, in actual work, the environmental protection targets within the evaluation range along the linear engineering of rail transit are highly specific and rich in types. For many sensitive points along the rail transit line, the use of analog measurement is theoretically feasible, but basically inoperable. Therefore, the present invention mainly simplifies the indoor secondary structure noise calculation method by using the indoor vibration main frequency sound radiation calculation to avoid the complexity brought by full-band calculation.

[0036] Beneficial effects:

[0037] The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines of the present invention is based on the wheel-rail vibration generation mechanism of trains in typical underground urban rail transit lines, and proposes a simple indoor secondary structure noise testing method, which provides technical support for the prediction of secondary structure noise in the environmental impact assessment prediction of underground urban rail transit lines, and provides a basis for the selection of vibration control measures and the reduction of residents' complaints.

[0038] The present invention is further described below through the accompanying drawings and specific implementation modes, but it is not intended to limit the protection scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of a simplified prediction method for indoor secondary structure noise caused by an underground line of urban rail transit in Example 1 of the present invention.

[0040] Description of main reference numerals:

[0041] 1 Train vibration source 2 Vibration propagation attenuation

[0042] 3 Building room 4 Secondary structure noise in building room DETAILED DESCRIPTION

[0043] Unless otherwise specified, in the following embodiments, the components described are all conventional components available on the market in this field, the connections between the components are all conventional connections, the software involved are all conventional software in this field, and the methods described are all conventional methods in this field.

[0044] Example 1

[0045] like Figure 1 As shown, it is a schematic diagram of a simplified prediction method for indoor secondary structure noise caused by an underground urban rail transit line in Example 1 of the present invention; wherein 1 is a train vibration source, 2 is vibration propagation attenuation, 3 is a building room, and 4 is the secondary structure noise in the building room; the simplified prediction method for indoor secondary structure noise caused by an underground urban rail transit line in Example 1 of the present invention has the following steps:

[0046] (1) Determine the underground train vibration source 1, that is, the 16-200 Hz vibration acceleration time-frequency domain signal at the tunnel wall;

[0047] (2) Determine the train vibration propagation attenuation 2, and determine the specific attenuation amount through calculation;

[0048] (3) Comprehensive analysis of indoor vibration of building 3;

[0049] (4) Prediction of secondary structure-borne noise 4 in indoor buildings (40 Hz, 50 Hz, 63 Hz and 80 Hz);

[0050] In step (1), the train vibration source 1 has two structural vibrations, one located below and one located vertically on the tunnel wall;

[0051] In step (1), the vibration acceleration of the train vibration source 1 on the vertical tunnel wall is usually determined by on-site analog test or simulation calculation analysis;

[0052] In order to predict secondary structural noise, the frequency range of the vibration acceleration of the train vibration source 1 is 16 to 200 Hz, and the 1 / 3 octave data within this frequency band can be provided;

[0053] In step (2), there are three vibration propagation paths (train vibration propagation attenuation 2) from the train vibration source 1 to the building room 3: one of them is refracted through the interface between the bedrock and the soil layer 2 and passes through the soil layer 2 to enter the soil layer 3, and then reaches the building; the second one passes through the soil layer 2, refracts at the interface between the soil layer 2 and the soil layer 3, passes through the soil layer 3 to reach the building; the third one passes through the soil layer 2 and the soil layer 3, reflects on the surface of the soil layer 3, and reaches the building after three reflections in the soil layer 3;

[0054] In step (3), the building is a three-story structure, the bottom floor of each structure has structural vibration (building ground vibration acceleration), the wall facing the train direction has structural vibration, and the wall of each structure facing the train side forms secondary structural noise;

[0055] According to the requirements of HJ453-2018 or other standards and specifications, the predicted values ​​of the ground vibration acceleration of the three buildings are obtained by correcting a series of parameters such as distance and building, and synchronously attenuated in equal proportion to give a 1 / 3 octave acceleration level;

[0056] Assuming a simple harmonic vibration with a frequency of f, a circular frequency of ω = 2πf, a vibration velocity amplitude of v0, and a vibration velocity of:

[0057] v=v0e jωt (Formula 1)

[0058] The vibration acceleration is:

[0059] a=jωv0e jωt (Formula 2)

[0060] Maximum 1 / 3 octave band sound pressure level of indoor secondary structure noise:

[0061] L p,i =L Vmid,i -22 = L amid,i -20lg(f)+22 (Formula 3)

[0062] Where: L amid,i - The vertical 1 / 3 octave vibration acceleration level (16-200 Hz) at the center of the indoor floor of the building during the train passing period, with the reference vibration acceleration value of 1×10 -6 m / s, dB;

[0063] i-the i-th 1 / 3 octave band, i=1~12;

[0064] Substitute the acceleration levels corresponding to the four frequency bands of 40Hz, 50Hz, 63Hz and 80Hz into equation 3 and solve to obtain the prediction of the secondary structure noise corresponding to the frequency division. Substitute it into the following equation 4 and solve to obtain the predicted value of the total sound pressure level of the secondary structure noise:

[0065]

[0066] Where: L Aeq,Tp - Maximum equivalent continuous A-level of indoor space of a building during a single train passing period, dB(A);

[0067] C f,i -A-weighted correction value for the ith frequency band, dB.

[0068] According to Formula 3, the corresponding relationship between vibration velocity and vibration acceleration 1 / 3 frequency division data is established through the mathematical relationship between acceleration and velocity. By solving, 4 frequency bands of 40 Hz, 50 Hz, 63 Hz and 80 Hz are obtained, which correspond to the maximum 1 / 3 octave sound pressure level of indoor secondary structure noise.

[0069] According to Formula 4, using 4 frequency bands of 40 Hz, 50 Hz, 63 Hz and 80 Hz, corresponding to the maximum 1 / 3 octave sound pressure level of indoor secondary structure noise, the predicted value of the total sound pressure level of secondary structure noise is obtained, thus completing the prediction of secondary structure noise.

[0070] The present invention adopts an empirical method to predict the indoor vibration of sensitive buildings in the underground line of urban rail transit, and then combines the relationship between vibration velocity and structural noise to establish the corresponding relationship between indoor vibration acceleration level and secondary radiation noise frequency division. By simplifying and selecting vibration acceleration prediction values ​​of 4 frequency bands such as 40Hz, 50Hz, 63Hz and 80Hz, the total sound pressure level prediction value of indoor secondary structure noise is obtained, which can simply and quickly complete the prediction of indoor secondary structure noise.

[0071] The simplified prediction method for indoor secondary structure noise caused by the underground line of urban rail transit of the present invention is based on the tunnel wall vibration source strength value adopted in conventional environmental assessment, which is a 1-80 Hz weighted vibration accelerometer. The listed vibration source strength requires the vibration acceleration frequency range to cover 16-20 Hz.

[0072] The vibration attenuates in the soil, and the vibration caused by the urban rail transit train is attenuated to the first floor of the indoor ground;

[0073] The vibration data used is not the 1-80Hz frequency band vibration data, but the 16-200Hz full-band vibration data as the basic data for prediction;

[0074] The calculation of the frequency division sound pressure level of secondary structure-borne noise skips the indoor vibration velocity level of the building and directly solves it through acceleration to ensure the consistency of the data;

[0075] Four frequency bands are selected: 40Hz, 50Hz, 63Hz and 80Hz, and the sound pressure level corresponding to the 1 / 3 octave of the secondary structure noise is predicted. The secondary structure noise is predicted once.

[0076] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims

1. A simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines, the steps of which are as follows: (1) Determine the vibration source of underground trains, i.e., the time-frequency domain signal of 16-200 Hz vibration acceleration at the tunnel wall; (2) Determine the attenuation of train vibration propagation and determine the specific attenuation amount through calculation; (3) Comprehensive analysis of indoor vibration of buildings; (4) Prediction of secondary structure noise in buildings.

2. According to claim 1, the simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines is characterized by: In step (1), the train vibration source has two structural vibrations, one located below and one located vertically on the tunnel wall.

3. The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines according to claim 1 is characterized in that: In step (1), the vibration acceleration of the train vibration source on the vertical tunnel wall is determined by on-site analog testing or simulation calculation analysis.

4. According to claim 1, the simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines is characterized by: In order to predict secondary structural noise, the frequency range of the vibration acceleration of the train vibration source is 16 to 200 Hz, and the 1 / 3 octave data within this frequency band can be given.

5. According to claim 1, the simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines is characterized by: In step (2), there are three vibration propagation paths from the train vibration source to the building room: one of them is refracted through the interface between the bedrock and soil layer 2 and passes through soil layer 2 to enter soil layer 3, and then reaches the building; the second one passes through soil layer 2, refracts at the interface between soil layer 2 and soil layer 3, passes through soil layer 3 to reach the building; the third one passes through soil layer 2 and soil layer 3, reflects on the surface of soil layer 3, and reaches the building after 3 reflections in soil layer 3.

6. The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines according to claim 1 is characterized by: In step (3), the building is a three-story structure, the bottom floor of each structure has structural vibration, the wall facing the train direction has structural vibration, and the wall of each structure facing the train side forms secondary structural noise.

7. The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines according to claim 1 is characterized by: In accordance with the requirements of HJ453-2018, the predicted values ​​of the ground vibration acceleration of the three buildings are obtained through distance and building parameter correction, and the 1 / 3 octave acceleration level is given by synchronous proportional attenuation.

8. The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines according to claim 1 is characterized by: Assuming a simple harmonic vibration with a frequency of f, a circular frequency of ω = 2πf, a vibration velocity amplitude of v0, and a vibration velocity of: v=v0e jωt (Formula 1) The vibration acceleration is: a=jωv0e jωt (Formula 2) Maximum 1 / 3 octave band sound pressure level of indoor secondary structure noise: L p,i =L Vmid,i -22 = L amid,i -20lg(f)+22 (Formula 3) Where: L amid,i - The vertical 1 / 3 octave vibration acceleration level (16-200 Hz) at the center of the indoor floor of the building during the train passing period, with the reference vibration acceleration value of 1×10 -6 m / s, dB; i-the i-th 1 / 3 octave band, i=1~12; Substitute the acceleration levels corresponding to the four frequency bands of 40Hz, 50Hz, 63Hz and 80Hz into equation 3 and solve to obtain the prediction of the secondary structure noise corresponding to the frequency division. Substitute it into the following equation 4 and solve to obtain the predicted value of the total sound pressure level of the secondary structure noise: Where: L Aeq,Tp - Maximum equivalent continuous A-level of indoor space of a building during a single train passing period, dB(A); C f,i -A-weighted correction value for the ith frequency band, dB.

9. The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines according to claim 8 is characterized by: According to Formula 3, the corresponding relationship between vibration velocity and vibration acceleration 1 / 3 frequency division data is established through the mathematical relationship between acceleration and velocity. By solving the problem, 4 frequency bands of 40 Hz, 50 Hz, 63 Hz and 80 Hz are obtained, which correspond to the maximum 1 / 3 octave sound pressure level of indoor secondary structure noise.

10. The simplified prediction method for indoor secondary structure noise caused by underground urban rail transit lines according to claim 9, characterized in that: According to Formula 4, using 4 frequency bands of 40 Hz, 50 Hz, 63 Hz and 80 Hz, corresponding to the maximum 1 / 3 octave sound pressure level of indoor secondary structure noise, the predicted value of the total sound pressure level of secondary structure noise is obtained, thus completing the prediction of secondary structure noise.

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