A highway noise reduction forest belt

Abstract

The present invention provides a highway noise reduction forest belt, characterized in that it includes a plurality of vegetation zones arranged in sequence along the direction from the roadbed to the outside; wherein the vegetation zone located at the most upstream is the initial vegetation zone, the initial vegetation zone is a herbaceous vine vegetation zone, and the height of the herbaceous vine vegetation zone is 0.2-0.6 meters; the heights of the vegetation zones located downstream of the initial vegetation zone are all greater than or equal to the height of the initial vegetation zone; and the height of at least one vegetation zone is lower than the height of the vegetation zone adjacent to it and located upstream thereof. The noise reduction forest in the present invention is set to an undulating state in the extension direction, and the noise attenuation of the noise reduction forest is effectively improved under the condition of comprehensively considering the sound absorption of vegetation leaves, branches, and the diffusion, scattering and diffraction of sound by vegetation.

Description

Technical Field

[0001] The invention belongs to the field of traffic noise control, and in particular relates to a highway noise reduction forest belt. Background Art

[0002] With the rapid development of highway construction in my country, the impact of highways on residents and the environment along the highway has also received widespread attention. When discussing the environmental problems caused by highways, noise pollution is an important aspect. The noise pollution caused by the continuous flow of vehicles on the highway will seriously affect the health of residents along the highway. Therefore, corresponding noise reduction measures must be taken for sections with noise pollution problems to eliminate the adverse effects of noise.

[0003] In the prior art, planting noise reduction forests is a commonly used noise reduction measure in highway areas. The shielding effect of plants can reduce the noise generated by vehicle driving. For example, Chinese patent document CN101624812A provides a method for reducing highway noise by using noise reduction forests. This method uses mixed forest belts or pure forest belts to reduce noise on the roadside of fill sections and excavation sections. The trees are planted in layers along both sides of the highway in the order of low to high. Specifically, shrubs, small trees, and trees are planted in layers along both sides of the highway in the order of low to high. The shrub planting width is 5m to 10m, and the average planting density is 25 plants / m. 2 , with an average crown height of 1m. In the excavated road section, noise reduction forests are planted in evergreen pure forest belts to reduce noise. In the area close to the highway, evergreen small trees are planted. The planting width of the small tree belt is 5 to 10m, the average planting density is 2m×2m, and the average crown height is 2.5m. Large trees are planted at the top of the slope. The planting width of the large tree belt is 10m to 30m, the average planting density is 5m×5m, and the average crown height is 5m. The ground cover is lawn.

[0004] The method of setting plants low first and high later in the noise reduction forest in the above-mentioned prior art is a method commonly used by technical personnel in this field, which can achieve good noise reduction effects. However, for roads, the planting width of noise reduction forests generally does not exceed 40m, so the area on both sides that can be used to plant plants is often limited. Therefore, if we stick to the setting method in the prior art, the noise reduction effect of the noise reduction forest will be limited to a certain extent. How to further improve the noise reduction effect of the noise reduction forest within a limited arrangement range is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0005] The present invention solves the technical problem that the noise reduction effect of noise reduction forests in the prior art is limited, and further provides a highway noise reduction forest belt with better noise reduction effect.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] A highway noise reduction forest belt comprises a plurality of vegetation zones arranged in sequence along a direction from a roadbed to an outer side; wherein the vegetation zone located at the most upstream is an initial vegetation zone, the initial vegetation zone is a herbaceous vine vegetation zone, and the height of the herbaceous vine vegetation zone is 0.2-0.6 meters;

[0008] The heights of the vegetation areas downstream of the initial vegetation area are all greater than or equal to the height of the initial vegetation area; and the height of at least one vegetation area is lower than the height of the vegetation area adjacent to it and located upstream of it.

[0009] Among the multiple vegetation areas arranged in sequence along the direction pointing outward from the roadbed, except for the herbaceous vine vegetation area located at the upstream, the width of other vegetation areas along the direction pointing outward from the roadbed is n times the standard width, n≥1 and is an integer; the standard width is 5-5.5 meters.

[0010] The width of the herbaceous vine vegetation area located at the uppermost stream in the direction from the roadbed to the outside is smaller than the standard width, or is larger than the standard width but smaller than 2 times of the standard width.

[0011] When the width of the herbaceous vine vegetation area located at the most upstream in the direction from the roadbed to the outside is less than the standard width, ∑N i The value of is a prime number; when the width of the herbaceous vine vegetation area located at the uppermost reaches is greater than the standard width but less than 2 times of the standard width, ∑N i The value of is a prime number minus 1; where N i It represents the value obtained by dividing the width of the i-th vegetation area downstream from the starting point of the noise reduction forest belt by the standard width, i≥2.

[0012] When the roadbed is higher than the ground height and the height difference is greater than 2 meters, the noise reduction forest belt includes at least two combined vegetation areas arranged in sequence along the direction pointing outward from the roadbed, each of the combined vegetation areas includes a first area located upstream and a second area located downstream, the first area located at the upstreammost end of the noise reduction forest belt is the initial vegetation area, and the remaining first areas are herbaceous vine vegetation areas or shrub vegetation areas; the height of the planting area in the second area in each of the combined vegetation areas is higher than that of the first area; the vegetation area located downstream of the initial vegetation area and adjacent to the initial vegetation area is a tree vegetation area with a height of 5-7 meters.

[0013] Among the combined vegetation areas arranged in sequence along the direction pointing outward from the roadbed, the height of the first area in the combined vegetation area located downstream is greater than or equal to the height of the first area in the combined vegetation area located upstream, and at the same time, the height of the first area in the combined vegetation area located downstream is less than the height of the vegetation area located upstream and adjacent to it.

[0014] When the height difference between the roadbed and the ground is less than or equal to 2 meters, the noise reduction forest belt includes an initial vegetation area, an intermediate area and an end area arranged in sequence along the direction from the roadbed to the outside; the intermediate area includes at least one vegetation area, and the height of the highest vegetation area in the intermediate area is higher than the heights of the initial vegetation area and the end area; and at least one planting area in the intermediate area is a tree vegetation area with a height of 3-8 meters; the end area is a shrub vegetation area with a height higher than the initial vegetation area.

[0015] The height of the lowest vegetation area in the middle area is greater than or equal to the highest heights of the initial vegetation area and the terminal area.

[0016] When the roadbed is lower than the ground height and the height difference is greater than 2 meters, the noise reduction forest belt includes an initial vegetation area located at the upstream end and planted on the slope, and a high vegetation area and a low vegetation area located above the slope and arranged in sequence along the roadbed pointing outward. The high vegetation area is planted with trees, and the low vegetation area is planted with shrubs.

[0017] Herbaceous vine vegetation is also planted in some tree vegetation areas and / or some shrub vegetation areas in the noise reduction forest.

[0018] The density of each planting area of ​​the noise reduction forest belt is 0.7~0.8.

[0019] The total leaf area of ​​arbor plants in the arbor vegetation area S t and vegetation effective height h e The ratio is greater than 2.

[0020] The advantages of the highway noise reduction forest belt described in the present invention are:

[0021] Unlike the traditional use of noise reduction forests for shielding, the noise reduction forests in the present invention are set up in an undulating state in the extension direction, that is, the height of at least one vegetation area is lower than the height of the vegetation area adjacent to it and located upstream. The present invention stipulates the setting method of roadside noise reduction forest belts under different roadbeds and different forest belt widths, taking into account the sound absorption of vegetation leaves and branches, and the diffusion, scattering and diffraction of sound by vegetation. The noise attenuation of the noise reduction forest is effectively improved through the combination configuration design method of different vegetation types and heights. The noise forest belt in the present invention uses the noise reduction forest belts set up within the red line range on both sides of the highway for noise protection, and is suitable for residential buildings along the roadside, which are mainly one-story and two-story houses.

[0022] For highway noise, since the wavelength of low-frequency noise is long, the wavelength reflects the diffraction ability of sound waves, so the diffraction ability of low-frequency noise is very strong. The existing noise reduction forest belt is achieved by setting vegetation to form lush branches and leaves formed by vegetation of different heights, which play an absorbing and blocking role in the propagation of traffic noise sound waves to achieve the design effect of the noise reduction forest belt. However, due to the limited height of the plants, it is difficult for them to attenuate noise, especially low-frequency noise. While setting the noise reduction forest belt to use lush branches and leaves for sound absorption and sound insulation, the present invention also uses the spatial width of the roadside forest belt to set different forest belt height levels according to the sound waves to form a forest belt sound wave scattering surface, so that when the road traffic noise passes through the noise reduction forest belt, it can not only reduce the noise by absorbing and blocking the sound waves, but also reduce a part of the sound wave energy by diffraction through the scattering surface formed on the surface of the forest belt, thereby improving the noise reduction effect of the forest belt.

[0023] Since the width of the forest belt is usually much larger than the height of the forest belt, the width of the forest belt is used to form a vegetation surface diffuser, which can effectively increase the noise reduction ability of the forest belt, especially the noise attenuation ability for medium and low frequency noise. For high roadbed sections and flat roadbed sections, the present invention sets the initial vegetation area as a herbaceous vine vegetation area with a height range of 0.2-0.6 meters. This short herbaceous vine vegetation forms an obvious height difference with the vegetation area located downstream thereof. This difference area has a significant scattering effect on low frequency noise, which can first promote the absorption of low frequency noise.

[0024] In the present invention, except for the herbaceous vine vegetation area located at the uppermost stream, each of the other vegetation areas is of standard width or an integer multiple of the standard width, where the standard width is set to 5-5.5 meters, which is consistent with the wavelength characteristics of the engine noise of heavy vehicles on the road, and is beneficial to improving the noise suppression effect of different scattering surfaces of the noise reduction forest.

[0025] The present invention also preferably has the same standard width for each vegetation zone of the noise reduction belt. When the width of the herbaceous vine vegetation zone located at the most upstream in the direction from the roadbed to the outside is smaller than the standard width, ∑N i The value of is a prime number; when the width of the herbaceous vine vegetation area located at the uppermost reaches is greater than the standard width but less than 2 times of the standard width, ∑N i The value of is a prime number minus 1; where N i It represents the value obtained by dividing the width of the i-th vegetation area downstream from the starting point of the noise reduction forest belt by the standard width, where i is greater than or equal to 2. The advantage of this setting is that the effective setting layer in the forest belt can be a prime number, because a prime forest belt will prevent the noise from being superimposed twice, that is, there will be a remainder when the width of the noise reduction forest is divided by the standard width, so that when the sound wave passes through the scattering surface formed by the forest belt, the sound wave scattering angle is as uniform as possible, which promotes the attenuation of the sound wave.

[0026] Compared with the existing forest belt setting method that only considers sound absorption and sound insulation, the noise reduction forest belt in the present invention can increase the sound energy attenuation capacity by an additional 30%.

[0027] In order to make the technical solution of the highway noise reduction forest belt described in the present invention more clear, the present invention is further described in detail below in conjunction with specific drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] like Figure 1 The figure shows the structure of the noise reduction forest belt when the roadbed height is 2m higher than the road surface height on both sides and the distance between the noise reduction forest belt and the roadside is less than 20m;

[0029] like Figure 2 The figure shows the structure diagram of the noise reduction forest belt when the roadbed height is 2m higher than the road surface height on both sides and the distance between the noise reduction forest belt and the roadside is less than 30m;

[0030] like Figure 3 The figure shows the structure of the noise reduction forest belt when the roadbed height is 2m higher than the road surface height on both sides and the distance between the noise reduction forest belt and the roadside is less than 40m;

[0031] like Figure 4 The figure shows the structure of the noise reduction forest belt when the height difference between the roadbed and the road surface on both sides is within 2m and the distance between the noise reduction forest belt and the road side is less than 20m;

[0032] like Figure 5 The figure shows the structure of the noise reduction forest belt when the height difference between the roadbed and the road surface on both sides is within 2m and the distance between the noise reduction forest belt and the road side is less than 30m;

[0033] like Figure 6 The figure shows the structure of the noise reduction forest belt when the height difference between the roadbed and the road surface on both sides is within 2m and the distance between the noise reduction forest belt and the road side is less than 40m;

[0034] like Figure 7 Shown is a schematic diagram of the structure of the noise reduction forest belt in the road cutting section;

[0035] The accompanying drawings are denoted as follows:

[0036] 1-roadbed; 2-first combined vegetation area; 3-second combined vegetation area; 4-third combined vegetation area; 21-first area of ​​the first combined vegetation area; 22-second area of ​​the first combined vegetation area; 221, 222-two vegetation areas in the second area of ​​the first combined vegetation area; 31-first area of ​​the second combined vegetation area; 32-second area of ​​the second combined vegetation area; 321, 322-two vegetation areas in the second area of ​​the second combined vegetation area; 41-first area of ​​the third combined vegetation area; 42-second area of ​​the third combined vegetation area; 5-starting area; 6-middle area; 61, 62, 63, 64, 65-multiple vegetation areas in the middle area; 7-end area; 8-herbaceous vine vegetation area on the slope; 9-high vegetation area; 10-low vegetation area. DETAILED DESCRIPTION

[0037] It should be noted that in the following embodiments, the "height of the region" or "height of the vegetation area" refers to the height of the highest type of plants in the region or vegetation area; the "width" in the following embodiments refers to the length in the direction from the roadbed to the outside, and the "outside" of the roadbed here refers to the direction from the center line of the roadbed to the side of the roadbed. The "upstream" and "downstream" involved are also in the direction from the roadbed to the outside. In this direction, the side close to the roadbed is "upstream", and the opposite is "downstream". Example 1

[0038] This embodiment is aimed at high roadbed, that is, the roadbed height is more than 2m higher than the ground height on both sides. In this embodiment, the roadbed 1 is 4m higher than the ground on both sides, and the distance between the roadside noise reduction forest belt and the roadside can be less than 20m. Figure 1 As shown, no vegetation is planted on the side slope of the roadbed, and the noise reduction forest belt starts from the side edge of the roadbed, i.e., the bottom edge of the slope, and includes two combined vegetation areas arranged in sequence along the direction from the roadbed to the outside, each of the combined vegetation areas includes a first area located upstream and a second area located downstream, and the first area of ​​each of the combined vegetation areas is a herbaceous vine vegetation area; the height of the second area in each of the combined vegetation areas is higher than that of the first area; in this embodiment, the second area 22 of the first combined vegetation area located upstream is planted with trees and is a tree vegetation area; the second area 32 of the second combined vegetation area located downstream is a shrub vegetation area.

[0039] Among them, the first area 21 of the first combined vegetation area located upstream is an initial vegetation area, in which the height of the herbaceous vine vegetation is 0.2-0.6m and the width is set to 3.5m.

[0040] The width of the second area 22 of the first combined vegetation area is also 5 meters, which is also the standard width of the noise reduction forest belt in this embodiment. Except for the herbaceous vine vegetation area located at the uppermost stream, the width of other vegetation areas in the direction from the roadbed to the outside is n times the standard width, where n is an integer greater than or equal to 1. The height of the tree plants in this area is 5 to 7 meters, and the planting width is also 5 meters, that is, evenly distributed in the entire second area. The total vegetation leaf area S of the tree plants is t and vegetation effective height h e The ratio is greater than 2.

[0041] The height of the herbaceous vine vegetation in the first area 31 of the second combined vegetation area located downstream is 0.2-0.6 m, and the width is set to 5 m.

[0042] The height of the shrub vegetation in the second area 32 of the second combined vegetation area is 1.5-2.5 m, the width of the second area is 5 m, and the length of the shrub branches is between 0.3 m and 1.2 m.

[0043] In the four vegetation zones arranged in sequence in this embodiment, the height of the third vegetation zone is less than the height of the vegetation zones located upstream and downstream and adjacent to it, so there are fluctuations in height. The canopy density of each vegetation zone is greater than or equal to 0.7. As a preferred embodiment, the canopy density of each vegetation zone in this embodiment is 0.7-0.8.

[0044] At the same time, ∑N in this embodiment i =N2+N3+N4=5 / 5+5 / 5+5 / 5=3 (i≥2 and is an integer), 3 is a prime number, so that the effective setting layer in the forest belt is a prime number. Example 2

[0045] This embodiment is aimed at high roadbed, that is, the roadbed height is more than 2m higher than the ground height on both sides. In this embodiment, the roadbed is 4m higher than the ground on both sides, and the distance between the roadside noise reduction forest belt and the roadside can be less than 30m. Figure 2 As shown, no vegetation is planted on the side slope of the roadbed, and the noise reduction forest belt starts from the side edge of the roadbed, i.e., the bottom edge of the slope, and includes two first combined vegetation areas 2 and second combined vegetation areas 3 arranged in sequence along the direction from the roadbed to the outside, each of the combined vegetation areas includes a first area located upstream and a second area located downstream, and the first area of ​​each of the combined vegetation areas is a herbaceous vine vegetation area; the height of the second area in each of the combined vegetation areas is higher than that of the first area; in this embodiment, the second area 22 of the first combined vegetation area located upstream is planted with trees; the second area 32 of the second combined vegetation area located downstream is also a tree vegetation area.

[0046] Among them, the first area 21 of the first combined vegetation area located upstream is an initial vegetation area, and the height of the herbaceous vine vegetation in the initial vegetation area is 0.2-0.6m, and the width is set to 3.5m.

[0047] The second area 22 of the first combined vegetation area includes two tree vegetation areas 221 and 222. The width of the tree vegetation area 221 located upstream is 5 meters, which is also a standard width corresponding to the noise reduction forest belt in this embodiment. Except for the herbaceous vine vegetation area located at the most upstream, the width of other vegetation areas in the direction from the roadbed to the outside is n times the standard width, where n is an integer greater than or equal to 1. The height of the tree plants planted in the tree vegetation area 221 is 5~7m, and the total leaf area S of the tree vegetation is 2.5~3.5m. t and vegetation effective height h e The ratio is greater than 2; in the upstream tree vegetation area 221, herbaceous vine vegetation is also planted, the height of the herbaceous vine vegetation is 0.4-0.5m, and the planting width is also 5m. The height of the tree plants in the downstream tree vegetation area 222 is 3-4m, and the planting width is also 5m, which is a standard width. The total leaf area S of the tree t and vegetation effective height h e The ratio is greater than 2, and herbaceous vine vegetation is also planted in the tree vegetation area 222 located downstream. The herbaceous vine vegetation has a height of 0.4-0.5m and a width of 5m.

[0048] The height of the herbaceous vine plants in the first area 31 of the second combined vegetation area located downstream is 0.2-0.6 m, and the width is set to 10 m, which is 2 standard widths.

[0049] The width of the second area 32 of the second combined vegetation area located downstream is 5 meters. It is a tree vegetation area, in which the height of the tree plants planted is 3-4 meters, and the planting width is also 5 meters, that is, the tree plants are distributed throughout the second area. The total area of ​​the tree leaves S t and vegetation effective height h e The ratio is greater than 2; the area is also planted with herbaceous vine vegetation, the height of the herbaceous vine vegetation is 0.2-0.6m, and the planting width is also 5m.

[0050] In the five vegetation areas arranged in sequence in this embodiment, the canopy density of each vegetation area is greater than or equal to 0.7. As a preferred implementation, the canopy density of each vegetation area in this embodiment is 0.7-0.8.

[0051] In this embodiment, the width of the first area 21 of the first combined vegetation area is 3.5 meters, which is smaller than a normal width. The advantage of this setting is that there is a remainder when the noise reduction forest width is divided by the standard width, so that when the sound wave passes through the scattering surface formed by the forest belt, the sound wave scattering angle is as uniform as possible, thereby promoting the attenuation of the sound wave.

[0052] At the same time, ∑N in this embodiment i =N2+N3+N4+N5=5 / 5+5 / 5+10 / 5+5 / 5=5 (i≥2, and is an integer), 5 is a prime number, so that the effective setting layer in the forest belt is a prime number to prevent the noise from being superimposed twice. Example 3

[0053] This embodiment is aimed at high roadbed, that is, the roadbed height is more than 2m higher than the ground height on both sides. In this embodiment, the roadbed is 4m higher than the ground on both sides, and the distance between the roadside noise reduction forest belt and the roadside can be less than 40m. Figure 3 As shown, no vegetation is planted on the side slope of the roadbed. The noise reduction forest belt starts from the side edge of the roadbed, i.e., the bottom edge of the slope, and includes three first combined vegetation areas 2, second combined vegetation areas 3, and third combined vegetation areas 4 arranged in sequence along the direction pointing outward from the roadbed. Each of the combined vegetation areas includes a first area located upstream and a second area located downstream.

[0054] Among them, the first area 21 of the first combined vegetation area is a herbaceous vine vegetation area, which is an initial vegetation area. The height of the herbaceous vine vegetation is 0.2-0.6m, and the width is set to 3.5m.

[0055] The second area 22 of the first combined vegetation area includes two tree vegetation areas 221 and 222, wherein the tree vegetation area 221 located upstream has a width of 5 meters, i.e., a standard width. Except for the herbaceous vine vegetation area located at the most upstream, the width of the other vegetation areas in the direction from the roadbed to the outside is n times the standard width, where n is an integer greater than or equal to 1. The height of the trees in the tree vegetation area 221 located upstream is 5 to 7 meters, and the total leaf area S of the tree vegetation is 1. t and vegetation effective height h e The ratio is greater than 2. The width of the tree vegetation area 222 located downstream is also 5 meters, the height of the trees planted therein is 3-4 meters, and the total leaf area of ​​the tree vegetation is S t and vegetation effective height h e The ratio is also greater than 2. Herbaceous vines are planted in both tree vegetation areas, with a height of 0.2-0.6m.

[0056] The width of the first area 31 of the second combined vegetation area is 5 meters, which is a shrub vegetation area. Herbaceous vines are also planted in the shrub vegetation area. The height of the shrubs is 1.5-2.0m, the height of the herbaceous vines is 0.2-0.6m, and the length of the shrub branches is between 0.3m and 1.2m.

[0057] The second area 32 of the second combined vegetation area includes two vegetation areas 321 and 322. The width of the vegetation area 321 located upstream is 5 meters, and it is a tree vegetation area, in which the tree height is 2.5-3 meters, and the total area of ​​the tree leaves is S t and vegetation effective height h e The ratio is greater than 2; the vegetation area 221 is also planted with grass and vines, and the height of the herbaceous vines is 0.2-0.6m. The width of the vegetation area 322 located downstream is also 5 meters, which is a shrub vegetation area. Herbaceous vines are also planted in the vegetation area 222, among which the height of shrubs is 2.5-3m, and the height of herbaceous vines is 0.2-0.6m. The planting width is 5m, and the length of the shrub branches is required to be between 0.3m and 1.2m.

[0058] The first area 41 of the third combined vegetation area has a width of 5 meters, which is a shrub vegetation area. Grass and vine vegetation are also planted in the shrub vegetation area. The height of the shrub vegetation is 1.5-2 meters, the height of the herbaceous vine vegetation is 0.2-0.6 meters, and the width is 5 meters. The length of the shrub branches is between 0.3 meters and 1.2 meters.

[0059] The width of the second area 42 of the third combined vegetation area is 5 meters, which is a tree vegetation area, and grass and vine vegetation is planted at the same time, wherein the height of the tree plants is 3-4 meters, the height of the herbaceous vine vegetation is 0.2-0.6 meters, and the total leaf area of ​​the tree plants is S t and vegetation effective height h e The ratios are all greater than 2.

[0060] In this embodiment, the height of the first area in the second combined vegetation area 3 and the third combined vegetation area 4 is lower than the height of the vegetation area located upstream and adjacent thereto, and is lower than the height of the vegetation area located downstream and adjacent thereto, thus forming ups and downs. In this embodiment, the 8 vegetation areas arranged in sequence have a canopy density of each vegetation area greater than or equal to 0.7. As a preferred embodiment, the canopy density of each vegetation area in this embodiment is 0.7-0.8.

[0061] At the same time, ∑N in this embodiment i=N2+N3+N4+N5+N6+N7+N8+N9=5 / 5+5 / 5+5 / 5+5 / 5 +5 / 5+5 / 5+5 / 5=7 (i≥2 and is an integer), 7 is a prime number, which makes the effective setting layer in the forest belt a prime number to prevent the noise from being superimposed twice. Example 4

[0062] This embodiment is for flat roadbed, that is, the difference between the roadbed height and the ground height on both sides is within 2m. In this embodiment, the roadbed is 2m higher than the ground on both sides, and the distance between the roadside noise reduction forest belt and the roadside is less than 20m. Figure 4 As shown, no vegetation is planted on the side slope of the roadbed. The noise reduction forest belt starts from the side edge of the roadbed, i.e., the bottom edge of the slope, and includes three starting areas 5, middle areas 6, and terminal areas 7 arranged in sequence along the direction from the roadbed to the outside, wherein the starting area 5 is a herbaceous vine vegetation area, i.e., the initial vegetation area; the middle area 6 is planted with trees, and the terminal area 7 is planted with shrubs, and the height of the middle area is higher than that of the starting area and the terminal area.

[0063] In this embodiment, the width of the starting area is 8.5 m, and the height of the herbaceous vine vegetation planted in the starting area is 0.4-0.5 m.

[0064] The width of the middle area is 5 meters, which is a standard width. Trees are planted, which is a tree vegetation area; the height of the tree plants is 3.5-4.5 meters, the planting width is 5 meters, and the total area of ​​the vegetation leaves is S t and vegetation effective height h e The ratio is greater than 2.

[0065] The width of the terminal area is 5m, which is a shrub vegetation area. Herbaceous vine vegetation is also planted in this shrub vegetation area. The height of the shrub vegetation is required to be about 1.5-2.5m, the height of the herbaceous vine vegetation is 0.2-0.6m, the planting width is 5m, and the length of the shrub branches is between 0.3m and 1.2m.

[0066] In the three vegetation areas arranged in sequence in this embodiment, the height of the third vegetation area is less than the height of the vegetation area located upstream and adjacent to it, forming ups and downs. In this embodiment, the canopy density of each vegetation area is 0.7-0.8.

[0067] In this embodiment, ∑N i =N2+N3=5 / 5+5 / 5=2 (i≥2, and is an integer), which is the prime number 3 minus 1. In this embodiment, the width of the herbaceous vine vegetation area in the starting area is 8.5 meters, which also includes a standard width, so that the effective setting layer in the forest belt is 3 layers, which is a prime number to prevent the noise from being superimposed twice. Example 5

[0068] This embodiment is for flat roadbed and road surface, that is, the difference between the roadbed height and the road surface height on both sides is within 2m. In this embodiment, the roadbed is 2m higher than the road surface on both sides, and the distance between the noise reduction forest belt and the road side is less than 30m. Figure 5 As shown, no vegetation is planted on the slope of the roadbed. The noise reduction forest belt starts from the side edge of the roadbed, i.e., the bottom edge of the slope, and includes three starting areas 5, middle areas 6, and end areas 7 arranged in sequence from the roadbed to the outside, wherein the starting area 5 is a herbaceous vine vegetation area, i.e., the initial vegetation area. The middle area 6 is planted with trees, and the end area 7 is planted with shrubs. The height of the highest vegetation area in the middle area is higher than that of the starting area and the end area.

[0069] In this embodiment, the width of the starting area is 8.5 m, and the height of the herbaceous vine vegetation planted in the starting area is 0.2-0.6 m.

[0070] The middle area 6 includes two vegetation areas 61 and 62, wherein the width of the upstream vegetation area 61 is 5m, which is a shrub vegetation area, wherein the height of the shrub vegetation is 1.5-2.5m, and the length of the shrub branches is between 0.3m and 1.2m. The width of the downstream vegetation area 62 is 10m, which is a tree vegetation area, and herbaceous vine vegetation is also planted, wherein the height of the tree vegetation is required to be about 3.5-4.5m, and the height of the herbaceous vine vegetation is 0.2-0.65m. The total leaf area S of the tree t and vegetation effective height h e The ratio is greater than 2. In this embodiment, there is a height difference between the two vegetation areas in the middle area.

[0071] The width of the terminal area 7 is 5m, which is a shrub vegetation area, and herbaceous vine vegetation is also planted. The height of the shrubs is 1.5-2.5m, the height of the herbaceous vine vegetation is 0.2-0.6m, and the length of the shrub branches is between 0.3m and 1.2m.

[0072] In the four vegetation areas arranged in sequence in this embodiment, the height of the fourth vegetation area is less than the height of the vegetation area located upstream and adjacent to it, forming ups and downs. In this embodiment, the canopy density of each vegetation area is 0.7-0.8.

[0073] In this embodiment, ∑N i=N2+N3+N4=5 / 5+10 / 5+5 / 5=4 (i≥2, and is an integer), which is the prime number 5 minus 1. In this embodiment, the width of the herbaceous vine vegetation area in the starting area is 8.5 meters, which includes a standard width, so that the effective setting layer in the forest belt is 5 layers, which is a prime number, preventing the noise from being superimposed twice. Example 6

[0074] This embodiment is for flat roadbed, that is, the difference between the roadbed height and the ground height on both sides is within 2m. In this embodiment, the roadbed is 2m higher than the ground on both sides, and the distance between the roadside noise reduction forest belt and the roadside is less than 40m. Figure 6 As shown, no vegetation is planted on the side slope of the roadbed. The noise reduction forest belt starts from the side edge of the roadbed, i.e., the bottom edge of the slope, and includes three starting areas 5, middle areas 6, and terminal areas 7 arranged in sequence along the direction from the roadbed to the outside, wherein the starting area 5 is a herbaceous vine vegetation area, and the starting area 5 is an initial vegetation area; the middle area 6 is planted with trees, and the terminal area is planted with shrubs, and the height of the highest vegetation area in the middle area is higher than that of the starting area 5 and the terminal area 7.

[0075] In this embodiment, the width of the starting area 5 is 8.5 m, and the height of the herbaceous vine vegetation planted in the starting area 5 is 0.2-0.6 m.

[0076] The middle area includes five vegetation areas 61, 62, 63, 64, and 65, which are the first shrub vegetation area, the first tree vegetation area, the second tree vegetation area, the second shrub vegetation area, and the third tree vegetation area. Vegetation area 61, i.e. the first shrub vegetation area, has a width of 5m, the height of the planted shrubs is 1.5-2.5m, and the length of the shrub branches is between 0.3m and 1.2m. Vegetation area 62, i.e. the first tree vegetation area, has a width of 5m, the height of the planted tree vegetation is 6-8m, and the vegetation area also has herbaceous vines, the height of the herbaceous vines is 0.2-0.6m, and the total area of ​​the tree leaves in this area is S t and vegetation effective height h e The ratio is greater than 2. The width of the vegetation area 63, i.e. the second tree vegetation area, is 5 m, the height of the tree vegetation is 3-5 m, and the total area of ​​the planted tree leaves is S t and vegetation effective height h eThe ratio is greater than 2. The width of vegetation zone 64, i.e. the second shrub vegetation zone, is 5 m, wherein the height of the shrub plants is 1.5-2.5 m, and the length of the shrub branches is between 0.3 m and 1.2 m. The second shrub vegetation zone is also planted with herbaceous vines with a height of 0.2-0.6 m. The width of vegetation zone 65, i.e. the third tree vegetation zone, is 5 m, wherein the height of the tree vegetation is about 6-8 m, and the total area of ​​the planted tree leaves is S t and vegetation effective height h e The ratio is greater than 2.

[0077] The terminal area 7 is a shrub vegetation area, and herbaceous vine vegetation is also planted there, with a width of 5 meters, wherein the height of the shrubs is 1.5-2.5m, the height of the herbaceous vine vegetation is 0.2-06m, and the length of the shrub branches is between 0.3m and 1.2m.

[0078] In the seven vegetation zones arranged sequentially in this embodiment, the density of each vegetation zone is 0.7-0.8.

[0079] In this embodiment, ∑N i =N2+N3+N4+N5+N6+N7=5 / 5+5 / 5+5 / 5+5 / 5+5 / 5+5 / 5=6 (i≥2 and is an integer), which is the prime number 7 minus 1. In this embodiment, the width of the herbaceous vine vegetation area in the starting area is 8.5 meters, which includes a standard width, so that the effective setting layers in the forest belt are 7 layers, which is a prime number and can prevent the noise from being superimposed twice. Example 7

[0080] This embodiment is aimed at the cutting section, that is, the situation where the height difference between the side slopes on both sides and the road surface is greater than 2 meters. In this embodiment, the height difference between the side slopes on both sides and the road surface is 3 meters. Figure 7 As shown, the noise reduction forest belt includes a herbaceous vine vegetation area 8 planted on the slope, namely the initial vegetation area, and a high vegetation area 9 and a low vegetation area 10 arranged in sequence along the roadbed pointing outward above the slope, wherein the high vegetation area 9 is planted with trees, and the low vegetation area 10 is planted with shrubs.

[0081] In this embodiment, the height of the herbaceous vine vegetation laid on the slope is 0.2-0.6m, and the width is set equal to the width of the slope; the width of the high vegetation area 9 is 5 meters, and tree vegetation + herbaceous vine vegetation are planted. The height of the tree vegetation is about 3-4m, the height of the herbaceous vine vegetation is 0.2-0.6m, the width is 5m, and the total area of ​​the vegetation leaves is S t and vegetation effective height h e Ratio is greater than 2. Ratio is greater than 2.

[0082] There are 10 shrubs and herbaceous vines in the low vegetation area. The height of the shrubs is 1.8-2.2m, the height of the herbaceous vines is 0.2-0.6m, the planting width is 5m, and the length of the shrub branches is between 0.3m and 1.2m.

[0083] The specific types of herbaceous vines, shrubs, and trees of different height ranges planted in the above Examples 1-7 are detailed in the table below, and one or more of the plants listed in the table can be selected according to climatic conditions. However, it should be noted that the vegetation selection in this application is not limited to this, and any suitable plant species can be selected according to local climatic conditions during actual implementation.

[0084] Table 1 Examples of eligible vegetation types in different regions

[0085]

[0086] In each vegetation zone, the plants are planted in the area in a uniform manner, that is, the plants in each vegetation zone are evenly distributed in the entire vegetation zone.

[0087] In order to verify the technical effect of the noise reduction forest belt in the present invention, the noise reduction effect of the noise reduction forest belt in the above-mentioned embodiments 1-7 was simulated according to the laboratory sound absorption and noise reduction test of vegetation and simulation calculation. When performing the simulation calculation, the insertion loss was calculated by selecting the observation point position located 40m from the roadside and 1.5m above the ground. The experimental results are shown in the following table.

[0088] Serial number Height difference between road surface and ground on both sides (m) Width of forest belt m Insertion loss dB Example 1 4 ＜20 3.1 Example 2 4 ＜30 4.4 Example 3 4 ＜40 5.9 Example 4 2 ＜20 3.6 Example 5 2 ＜30 5.2 Example 6 2 ＜40 6.7 Example 7 -3 ＜10 5.3

[0089] The above results show that the insertion loss corresponding to the noise reduction belt described in the present invention is 3.1-6.7dB. Compared with the existing noise reduction belts set to a single height and the noise reduction belts set to successively increasing heights, the noise reduction amount of the noise reduction belts described in the present invention can be effectively increased by 30%.

[0090] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the claims.

Claims

1. A highway noise reduction forest belt, characterized in that: It includes a plurality of vegetation areas arranged in sequence along the direction pointing outward from the roadbed; the vegetation area located at the most upstream is the initial vegetation area, the initial vegetation area is a herbaceous vine vegetation area, and the height of the herbaceous vine vegetation area is 0.2-0.6 meters; the height of the vegetation area located downstream of the initial vegetation area is greater than or equal to the height of the initial vegetation area; and the height of at least one vegetation area is lower than the height of the vegetation area adjacent to it and located upstream thereof; the canopy density of each vegetation area of ​​the noise reduction forest belt is 0.7-0.8; Among the multiple vegetation areas arranged in sequence along the direction from the roadbed to the outside of the noise reduction forest belt, except for the herbaceous vine vegetation area located at the uppermost stream, the width of the other vegetation areas along the direction from the roadbed to the outside is n times the standard width, where n ≥ 1 and is an integer; the standard width is 5-5.5 meters; The width of the herbaceous vine vegetation area located at the uppermost stream in the direction from the roadbed to the outside is less than the standard width, or is greater than the standard width but less than 2 times of the standard width; When the width of the herbaceous vine vegetation area located at the uppermost stream in the direction pointing outward from the roadbed is less than the standard width, the value of ∑Ni is a prime number; when the width of the herbaceous vine vegetation area located at the uppermost stream is greater than the standard width but less than twice the standard width, the value of ∑Ni is a prime number minus 1; wherein Ni represents the value obtained by dividing the width of the i-th vegetation area downstream from the starting point of the noise reduction forest belt by the standard width, i≥2.

2. The highway noise reduction forest belt according to claim 1 is characterized in that: When the roadbed is higher than the ground height and the height difference is greater than 2 meters, the noise reduction forest belt includes at least two combined vegetation areas arranged in sequence along the direction pointing outward from the roadbed, each of the combined vegetation areas includes a first area located upstream and a second area located downstream, the first area located at the upstreammost end of the noise reduction forest belt is the initial vegetation area, and the remaining first areas are herbaceous vine vegetation areas or shrub vegetation areas; the height of the planting area in the second area in each of the combined vegetation areas is higher than that of the first area; the vegetation area located downstream of the initial vegetation area and adjacent to the initial vegetation area is a tree vegetation area with a height of 5-7 meters.

3. The highway noise reduction forest belt according to claim 2 is characterized in that: Among the combined vegetation areas arranged in sequence along the direction pointing outward from the roadbed, the height of the first area in the combined vegetation area located downstream is greater than or equal to the height of the first area in the combined vegetation area located upstream, and at the same time, the height of the first area in the combined vegetation area located downstream is less than the height of the vegetation area located upstream and adjacent to it.

4. The highway noise reduction forest belt according to claim 1, characterized in that: When the roadbed is higher than the ground and the height difference between the roadbed and the ground is less than or equal to 2 meters, the noise reduction forest belt includes an initial vegetation area, an intermediate area and an end area arranged in sequence along the direction from the roadbed to the outside; the intermediate area includes at least one vegetation area, and the height of the highest vegetation area in the intermediate area is higher than the heights of the initial vegetation area and the end area; and the intermediate area has at least one planting area which is a tree vegetation area with a height of 3-8 meters; the end area is a shrub vegetation area with a height higher than the initial vegetation area.

5. The highway noise reduction forest belt according to claim 4 is characterized in that: The height of the lowest vegetation area in the middle area is greater than or equal to the highest heights of the initial vegetation area and the terminal area.

6. The highway noise reduction forest belt according to claim 1, characterized in that: When the roadbed is lower than the ground height and the height difference is greater than 2 meters, the noise reduction forest belt includes an initial vegetation area located at the upstream end and planted on the slope, and a high vegetation area and a low vegetation area located above the slope and arranged in sequence along the roadbed pointing outward. The high vegetation area is planted with trees, and the low vegetation area is planted with shrubs.

7. The highway noise reduction forest belt according to claim 1, characterized in that: Herbaceous vine vegetation is also planted in some tree vegetation areas and / or some shrub vegetation areas in the noise reduction forest.

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