Noise protection measures on highways. Architectural and planning activities

The attenuation of noise along the path of its propagation is provided by a set of construction and acoustic measures. These include rational planning solutions (primarily removing noise sources at an appropriate distance from objects), sound insulation, sound absorption and sound reflection of noise.

Measures to mitigate noise should already be envisaged at the stage of designing master plans for cities, industrial enterprises and planning of premises in individual buildings. Thus, it is unacceptable to place objects that require noise protection (residential buildings, laboratory and design buildings, computer centers, office buildings, etc.) in the immediate vicinity of noisy workshops and units (test boxes for aircraft engines, gas turbine units, compressor stations etc.). The noisiest objects should be combined into separate complexes. When planning rooms inside buildings, the maximum possible distance between quiet rooms and rooms with intense noise sources is envisaged.

To mitigate noise penetrating into isolated rooms, it is necessary: ​​to use materials and structures for ceilings, walls, partitions, solid and glazed doors and windows that provide proper sound insulation; use sound-absorbing lining of the ceiling and walls or artificial sound absorbers in isolated rooms; provide acoustic vibration isolation of units located in the same building; apply soundproof and vibration-damping coatings on the surface of pipelines passing in the room; use silencers in mechanical ventilation and air conditioning systems.

The machine room of elevators is unacceptable to be located directly above and below the living quarters, as well as next to them. Elevator shafts should not be adjacent to the walls of living rooms. Kitchens, bathrooms, bathrooms should be combined into separate blocks adjacent to the walls of staircases or to the same blocks of neighboring rooms, and separated from living quarters by a corridor, vestibule or hall.

It is forbidden to install pipelines and sanitary appliances on the enclosing structures of living rooms, as well as to place bathrooms and sewer risers next to them.

In all public, and sometimes in residential buildings, ventilation systems are used, sometimes air conditioning and air heating systems with mechanical equipment, can create significant noise.

To mitigate noise propagating through the channels of ventilation, air conditioning and air heating systems, special silencers (tubular, honeycomb, plate and chamber with sound-absorbing material) should be used, as well as air ducts and spurs lined with sound-absorbing material from the inside (Figure 1). The type and size of the muffler is selected depending on the required noise level, the allowable air flow rate and local conditions.

Soundproofing rooms from airborne noise is called the attenuation of sound energy in the process of its transmission through the fence. Most often, soundproof fences are walls, partitions, windows, doors, ceilings.

Currently, multilayer structures are used in construction practice more and more often. In some cases, they make it possible to obtain significant additional insulation compared to single-layer structures of the same mass (up to 12–15 dB).

In ceilings, to ensure the normative isolation of shock and airborne noise, a floor is made on an elastic basis (floating floor) or soft roll coatings are used. The joints between the internal enclosing structures, as well as between them and other adjacent structures, must be equipped in such a way that during operation there are no cracks and crevices that weaken the insulation (Figure 2).

Figure 1. Vent silencers (diagrams):

a --- tubular; b - lamellar; in - cellular;

g - cylindrical.

To increase sound insulation, double doors with a vestibule are also used. Door porches are provided with elastic gaskets. It is advisable to line the walls in the vestibule with sound-absorbing material. Doors should open in different directions.

Double windows are better isolated from airborne noise (up to 30 dB) than paired windows (20-22 dB).

Rice. 2.

a - floating floors on a solid flexible base (1 - floor covering; 2 - prefabricated or monolithic screed; 3 - soundproof flexible gasket; 4 - bearing part of the floor; 5 - plinth; b - floating floor on tape or artificial gaskets; in - overlap with soundproof materials (1 - soft rolled floor; 2 - overlap; 3 - plinth)

Recently, "sound-proof ventilation windows" have been widely used, which provide high sound insulation and at the same time allow ventilation of the room. These are two blank frames located at a distance of 100 mm or more from one another, with soundproof lining along the contour. Glasses of various thicknesses are used or a package of two glasses is used in one frame. A hole is equipped in the wall under the window, in which a box is installed in the form of a silencer with a small fan that provides air flow into the room.

Sound-absorbing structures are designed to absorb sound. These include sound-absorbing lining of enclosing surfaces of rooms and artificial sound absorbers. Sound-absorbing structures are widely used.

Most often, sound-absorbing lining is used: in educational, sports, entertainment and other buildings to create the best acoustic conditions for the perception of speech and music; in production shops, offices and other public premises (typing bureaus, machine counting stations, administrative premises, restaurants, waiting rooms of railway stations and air terminals, shops, canteens, banks, post offices, etc.); in corridor-type premises (schools, hospitals, hotels, etc.) to prevent the spread of noise.

Sanitary and hygienic requirements for sound-absorbing structures are, first of all, that they should not worsen hygienic conditions due to the shedding of fibers or material particles, and contribute to the accumulation of dust. The ease of cleaning dust from sound-absorbing structures is of particular importance in buildings with both increased sanitary and hygienic requirements (hospitals) and with increased dust emission (most industrial enterprises).

The effectiveness of sound-absorbing cladding in noisy rooms depends on the acoustic characteristics of the room, the characteristics of the selected structures, the method of their placement, the location of noise sources, the size of the room and the localization of design points. Usually it does not exceed 6-8 dB.

Measures to combat urban noise can be divided into two groups: architectural and planning and construction and acoustic.

Noise reduction along the path of its propagation from the source to residential development involves rational design of the road plan, transverse profiles and the use of the right of way.

In this case, if it is impossible to provide a buffer zone from roads to buildings, taking into account the requirements of sanitary standards, the following options for reducing traffic noise can be distinguished (Figure 3, a-k):

Figure 3. Schemes for protecting residential buildings from traffic noise.

a - noise barrier on the right of way of the highway;

b - a combination of a noise barrier on the right of way and a barrier located on the dividing strip (with a small width of the dividing strip, it is combined with fences);

c - a retaining wall from the side located close to the building;

d - green spaces within the buffer zone;

d - protective earth shafts;

e - road in a recess within settlements;

g - a road on an overpass with a device on the dividing strip and along the edges of noise barriers made of transparent plastic. The space under the overpass can be used for parking. For better protection, you can build a low soil shaft;

h - gallery with natural light;

and - a gallery open in the opposite zone from the building using the space above the gallery for parking and additional noise protection with green spaces;

k - a tunnel with complete isolation from traffic noise and the use of space above the tunnel for local traffic.

Various administrative measures may be used. These include: redistribution of traffic flows by city streets; restriction of movement at different times of the day in one direction or another; change in the composition of vehicles (for example, a ban on the use of trucks and buses with diesel engines on some streets of the city), etc.

When developing projects for planning and building cities, both natural conditions (terrain relief and green spaces) and special structures (screens near highways) can be used to protect against noise. You can also apply rational methods of zoning the territory according to the conditions of the noise regime for certain types of buildings, plots and sites for recreation, household needs, etc. noise transport population reduction

Consider possible options for noise protection in cities. First of all, in order to protect against noise in the design of cities and other settlements, it is necessary to clearly divide the territory according to its functional use into zones: residential, industrial (industrial), communal storage and external transport. Industrial (manufacturing) and communal storage areas, designed for large cargo flows along transport routes, are located so that they do not cross the residential area and do not wedged into it.

To protect against noise, when designing an external transport system, it is necessary to provide bypass railway lines in cities (to pass transit trains outside the city), place marshalling yards outside settlements, and technical stations and parks of reserve rolling stock, railway lines for freight traffic and access roads. ways - outside the residential area; to separate new railway lines and stations during new construction from the residential development of cities and other settlements of the SPZ; observe the proper distance from the boundaries of airports, factory, military airfields to the boundaries of residential development

When designing a street and road network, the maximum possible enlargement of Intermain areas, a decrease in the number of intersections and other transport hubs, and the installation of smooth curvilinear road junctions should be provided. In residential areas it is necessary to limit through traffic.

Functional zoning of the territories of microdistricts should be carried out taking into account the need to locate residential buildings and preschool institutions in areas that are the most remote from noise sources, highways, parking lots, garages, transformer substations, etc. In areas adjacent to noise sources, buildings can be built, in which allow higher sound levels. These are consumer services, trade, public catering, public utilities, administrative and economic and public institutions. Shopping centers and service blocks are usually built on the border of microdistricts along transport routes in the form of a single complex.

If residential development needs to be placed on the border of microdistricts along transport routes, it is advisable to use special types of noise-proof residential buildings. Depending on the insolation conditions, it is recommended to build: noise-protected residential buildings, the architectural and planning solutions of which are characterized by the orientation towards noise sources of the windows of auxiliary premises and no more than one living room without beds in multi-room apartments; noise-proof residential buildings with increased sound-proofing properties of external enclosing structures oriented towards noise sources and with built-in supply ventilation systems.

To ensure sanitary standards in apartments and on the territory of microdistricts, it is necessary to use compositional methods for grouping noise-proof buildings based on the creation of a closed space. When residential buildings are located along highways, one should not resort to compositional methods of grouping residential buildings, which are based on opening space towards the roadway.

If architectural and planning measures (breaks, building methods, etc.) do not provide the proper noise regime in buildings and on the territory of a residential microdistrict, and also in order to save the territory necessary to comply with territorial gaps with highways, it is advisable to use building acoustic methods: noise protection structures and devices, screens, noise protection strips of landscaping, and for residential buildings also window openings with increased sound insulation.

Various buildings and structures can be used as screens: buildings with reduced noise requirements; soundproof residential buildings; artificial or natural relief elements (dredging, ravines, earth ramparts, embankments, mounds) and walls (roadside retaining, enclosing and noise-protective). Noise barriers should be placed as close to the noise source as possible.

Buildings with reduced noise requirements (consumer services, trade, public catering, utilities; public and cultural and educational, administrative and economic institutions) and noise-protected residential buildings should be placed along noise sources in the form of frontal, if possible continuous, development. Premises of administrative, public, cultural and educational institutions with increased requirements for acoustic comfort (conference halls, reading rooms, auditoriums of theaters, cinemas, clubs, etc.) should be built on the opposite side from noise sources. They are separated from the highway by corridors, foyers, halls, cafes and buffets, auxiliary rooms.

As an additional means of noise protection, special noise protection strips of green spaces can be used. Several strips are formed with gaps between them equal to the height of the trees. The width of the strip should be at least 5 m, and the height of the trees should be at least 5-8 m. On the noise protection strips, the crowns of the trees should be tightly closed together.

State Committee
in architecture and urban planning
under Gosstroy of the USSR

Research and design institute for the development of master plans and urban development projects LenNIIPgradostroitelstva

NOISE POLLUTION
PART OF TERRITORIAL INTEGRATED SCHEMES
URBAN ENVIRONMENT PROTECTION

Leningrad 1989

A method is proposed for determining the state of noise pollution in urban areas in the development of integrated schemes for nature protection. The main most active sources of noise that cause pollution are classified, methods for determining their acoustic power and the degree of emission activity are given, sanitary standards for territories for various purposes are presented, criteria for assessing the territory by the noise load factor are identified. The recommendations are addressed to designers - urban planners, as well as specialists involved in urban environmental protection.

Introduction

1. MAIN SOURCES OF NOISE AND DETERMINATION OF THEIR CHARACTERISTICS

Rice. 1. Nomogram for determining the noise characteristic L Aeq of traffic flows
V is the weighted average flow rate; ρ - flow composition; N - traffic intensity

Table 1

Correction to the equivalent level, taking into account the characteristics of the path

Correction to the equivalent level, taking into account the type of building

L Aeq = 10 lgN + 13.3 lg + 8.4 ρ± ΔА /1/

Where N - traffic intensity; - weighted average flow rate; ρ - percentage of freight and public transport; ΔA is the sum of the corrections. On fig. 1 shows the nomogram, which must be used in the calculation /table. 12/. At the intersection of the main streets, the characteristics of the means of road transport should be determined by energy summation. The noise characteristic of railway train flows is the equivalent level L Aeq, dBA at a distance of 25 m from the axis of the railway track closest to the design point. The calculation of the noise characteristic of the railway flow is carried out according to the formula

, /2/

Where l a max - the maximum value of the sound level during the passage of a single train; Δ L And l - correction for the length of the composition; Δ L A - correction depending on the speed. Values ​​L Aeq. depending on the intensity of traffic are given in table. 3, 4, 5. The noise characteristic of water transport means is the equivalent noise level L Aeq., dBA at a distance of 25 m from the side of the vessels, depending on the hourly intensity of navigation during 8 hours of the most noisy period of the daytime. The values ​​of the equivalent flow of ships are given in Table. 6. The noise characteristic of the aircraft flight path is the reduced maximum sound level L A, dBA, determined by the location of the calculated point from the route, runway and flight stage. Table 3

Vehicle noise sources

Noise characteristics of railway trains

Amendments to the characteristics of the railway flow, taking into account the speeds, dBA

Noise characteristic of the flow of ships, A eq. , DBA

L Amax = L Almax + ΔL , /3/

Where L Almax - is determined depending on the flight stage according to fig. 2; ΔL - correction depending on the types of aircraft. The calculated equivalent level A eq on the ground during the flight of several aircraft along the route is determined by the formula

L Aeq = L Amax + Δ 2 - 25, /4/

Where Δ 2 is a correction that takes into account the intensity of the span and the time of exposure to noise, depending on the reduced number of spans / N n /

The combined exposure of several mobile sources is determined by the energy summation of the equivalent sound levels. Stationary noise sources in the city are very diverse both in terms of power and emission spectrum. The noise characteristics of industrial enterprises, thermal power plants, enterprises servicing means of transport, stations and other objects of road, water and railway transport located in a residential area is the corrected sound power level L pA /dBA/ and maximum corrected sound power level L pmax /dBA/. Industrial enterprises are considered as complex sources of noise, consisting of separate conditionally point and spatial emitters. It is advisable to represent the noise characteristic of enterprises in the form of equivalent levels along the contour of the enterprise. Approximate data on the noise levels of industrial enterprises depending on their type, dBA:

Rice. 2. Curves of the reduced maximum sound levels on the ground during takeoff and landing of aircraft
runway - runway; a - distance from the start of the run l, km; b - distance from the end of the runway l , km, c - distance from the start of the runway or the landing end of the runway

The calculated noise levels of industrial enterprises should be taken from the passport data of the sound levels of the most noisy equipment or, in the absence of this information, based on field measurements in accordance with GOST 12.1.026-80, GOST 12.1.028-80, GOST 12.1.024-81, GOST 12.1 .025-81. Obtaining the noise characteristics of various sources makes it possible to graphically represent the most noisy places, the main sources of noise, on the schematic image of the city, the numerical values ​​of which are displayed here using graphic techniques. The map of noise sources serves as the main material for calculating noise pollution zones and determining the state of noise pollution in the acoustic environment /Fig. 3/.

Rice. 3. Noise map and zoning according to acoustic loads
Noise sources: 1 - road network; 2 - railway; 3 - industrial enterprises; noise load zones: 4 - acoustic emergency; 5 - unfavorable; 6- favorable; 7- boundary of noise pollution zones

2. ASSESSMENT OF THE STATE OF NOISE POLLUTION OF THE TERRITORY

γ = L Aeq add. - L Aeq, /6/

Where L Aeq - estimated equivalent level in the territory; L Aeq add. - noise level allowed by sanitary standards. The percentage of the population living in conditions of noise pollution is very indicative.

, /7/

Where N d - the number of people living in conditions of noise discomfort; N total - the number of people living in the area under assessment. Using the indicator K t, the percentage of the territory located in the zone of noise pollution is determined

, /8/

Where S d - the area of ​​​​the territory of discomfort; S is the total area of ​​the territory under consideration. Table 7

Norms of permissible noise level in various functional areas

Where τ i is the coefficient of social danger for i th territory /zone/ with population N i and sound level L Aeq. The value of τ varies from 0 to 1, and the extreme values ​​correspond to levels of 55-80 dBA /80 dBA - the maximum value of the sound level in the main areas in real conditions/. The excess of the level in the territory above the standard value /55 dBA/ by 1 dBA corresponds to the value τ i = 0.04, i.e.

τ = 0.04(L Aeq.ter - 55), /10/

Where L Aeq.ter is the equivalent sound level, at i th territory /zones/, dBA; N i - the number of inhabitants per i th territory exposed to noise - L Aeq.

/11/

The criterion of social effectiveness of noise protection measures allows to determine the reduction of social danger after the implementation of noise protection measures

Where n, m are the population in the zone of acoustic discomfort before and after the noise protection measures. For a comparative assessment of the state of the acoustic regime, the specific noise load indicator should be used

, / 13/

Where n is the number of noise sources; i - source number; W i - acoustic power i-th source; S is the area of ​​the noise-prone area; I o \u003d 10 -12 W / m 2 - threshold value of sound intensity; k 1, k 2, k ... k n - correction calculation factors that take into account the shape of the territory, the nature of development, etc. In the process of invariant design, as a rule, it is required to carry out an approximate analysis of various solutions in a large number of planning and building options in a fairly short time in order to select the optimal one. For this, the most effective is the express method, which gives an assessment of the specific noise load in aggregated indicators, which will make it possible to identify the fundamental orientation of urban planning decisions. The idea of ​​an express assessment of the noise regime of the development area is to determine the most dangerous areas in terms of noise load and the number of people in them. The method is carried out by calculation and graphically in the form of differentiated indicators of the number of people exposed to noise pressure in each class of noise load levels from maximum to standard. Knowing the main design parameters of the development: area, average number of storeys, population, density of the network of main streets - it is possible to classify it according to the degree of noise hazard. The methodical sequence of the express method is presented in the form of a block diagram.

Main stages: obtaining the values ​​of the specific noise load of various functional areas by calculation in accordance with formula 13; ranking of the territory in accordance with the requirements of sanitary standards / tab. 7/ depending on the density, number of storeys and the nature of the development. Based on the calculations of the state of noise pollution for various building options, indicators were obtained / table. 8/, convenient to use in the assessment; final differentiation according to the degree of acoustic hazard / fig. 3/, The express method is convenient for assessing the state of noise pollution, both in the existing building and in projects for the development of its options. It allows you to determine the strategy of noise protection measures in order of priority. When ranking the territory, the task is to identify environmental conflict situations for purposeful planning of noise protection measures, which are also ranked according to the degree of priority of implementation, depending on the severity of the conflict and the magnitude of acoustic discomfort. To determine the effectiveness of noise protection measures, as well as to justify the choice of the most rational planning solution that contributes to noise protection, the concept of damage from the impact of noise on the population has been introduced.

Y o \u003d Y n - Y d / 14 /

The values ​​of Y n and Y d are calculated by the formulas

/15/

/16/

Where U n is the economic assessment of the annual damage from noise at night; At d - the same, in the daytime; N - the number of people living in the zone of negative noise impact,

A L H= 0.5∙2 0.15 - 6.1 = 10 0.045 L H -0.3 - 6.1 /17/

AT Ld= 2 0.1 - 5.3∙10 0.03 L d - 5.3 /18/

A L H, AT Ld- dimensional factors for external noise sources. The effectiveness of noise protection measures is determined by the formula

E \u003d R - Z, / 19 /

Where P is the annual economic result of targeted noise protection measures.

R \u003d Y o - Y / 20 /

Y o - economic assessment of annual damage before the implementation of measures; Y - the same, after the implementation of activities, Z - the annual reduced costs of the activities.

Z = C + E n K, /21/

Where C - annual operating costs; K - investment in activities; E n \u003d 0.12 - the standard coefficient of efficiency of capital investments. The criterion for the day of choosing the optimal option is the minimum annual reduced costs for the implementation of measures that ensure the maximum value of the annual economic effect

E \u003d (R - Z) max / 22 /

Table 8

Influence of the nature of development on the population in the zones of noise pollution

The use of these criteria makes it possible to qualitatively carry out a new assessment of the planning and development of urban areas and, from urban planning and social positions, to approve the feasibility and effectiveness of possible means and methods of noise protection.

3. NOISE PROTECTION MEASURES

, / 23/

Where I B - load index; N is the number of residents exposed to noise; q - coefficient of use of the building for residential purposes; C - relative building cost. The building utilization factor ranges from 0 to 1.5. Approximate values ​​of the coefficient of use of buildings for residential purposes / q /: The choice of noise protection measures in urban planning decisions is carried out in three areas: architectural and planning, architectural and construction, construction and construction. In the general system of noise protection measures for the early stages of design, such as CSE, the role of architectural and planning solutions is increasing, the most effective of which are: functional zoning of the territory, separation of residential, medical and recreational areas from industrial, utility and storage areas and main transport communications; formation of a city-wide system of green spaces that contribute to noise protection; routing of high-speed and freight roads bypassing residential areas and recreation areas; differentiation of the road network according to the composition of the traffic flow; the use of noise-protective properties of the relief when tracing highways; enlargement of inter-main territories to separate the main building blocks from transport highways and the choice of complex geometric forms of inter-main territories, giving a large area of ​​acoustic comfort. 3.1. Functional zoning of the urban area provides for a clear differentiation of individual functional areas according to their purpose and the interconnection of the noise load created in them with the indicator of the need for noise protection / 23 /. At the same time, the maximum removal of industrial zones, enterprises servicing all types of transport, transformer, boiler houses from residential, medical and recreational areas is ensured, or the issue of choosing individual construction and structural noise protection measures is considered if it is impossible to provide the necessary sanitary protection zone. 3.2. In the formation of urban areas, an important role is played by the system of the road network and the organization of traffic along it. When choosing the layout of the street and road network, it is advisable to consider the following issues: increasing the inter-main space with the intensive use of individual Main passages, provided with special construction and structural noise protection structures; differentiation of the street and road network according to its purpose, the removal of transit and freight traffic to non-residential areas; maximum use of natural relief elements. As noise protection structures on highways, the following can be recommended: a noise barrier on the right of way of the highway, or on the same subgrade; high working level of the embankment of the highway, set on the basis of acoustic considerations; excavation slopes, the depth of which is determined by acoustic calculation; retaining walls when the road is located in a recess; various ceilings erected over the carriageway in the form of galleries or tunnel ceilings; noise-protective soil shafts; flyovers. The noise protection option adopted for implementation, with economic feasibility and ensuring noise reduction to the values ​​regulated by sanitary standards, should include additional requirements: do not contribute to the snow-covering of the subgrade of roads, do not impede snow removal from the roadway, fit well into the landscape and not interfere with inspection of the surrounding landscape by the riders, not to create the danger of traffic accidents, to occupy the smallest possible width of the right-of-way. The material for the construction of noise protection structures should be selected based on structural and economic considerations. The most widespread are concrete and reinforced concrete. Steel, aluminum, various plastic materials, glass, wood, etc. are also used. The required surface density of structures depends on the required sound insulation /noise penetration through the surface of the structure/, determined by the magnitude of the required reduction in sound level. Being a means of protecting the environment from traffic noise, noise protection structures themselves become its element, shaping the appearance of the highway and determining its functioning both from a technical and aesthetic point of view /Fig. four/. Noise protection structures are a harmonious, rational proportions element of the surrounding ensemble, which is in "balance" with the external environment, while they must be functional and devoid of architectural excesses. The reconstruction of roads and the development of traffic noise protection projects makes sense only in cases where the excess of sanitary standards is at least 3 dBA, since only the excess begins to be perceived by the human ear.

Rice. 4. Options for the organization of motor transport routes and the influence of the subgrade profile on the spread of traffic noise

The effect of the concentration of traffic in a separate corridor can be enhanced by the attractiveness of the main trunk roads and the creation of difficult patterns when driving along a secondary network, by organizing one-way traffic, designing access roads, and locally reducing traffic intensity, and hence noise. This effect can also be achieved by administrative measures to organize traffic, such as the prohibition of through and freight traffic. Elements of highways that can lead to a change in the speed of movement / crossing roads / should be located in areas where some increase in the calculated sound levels will not be perceived as undesirable. It is possible to reduce the noise produced by traffic by influencing the design sound level by operational control through: coordinated traffic light control; introduction of one-way traffic; construction of bypasses of settlements or individual residential areas; prohibition of traffic on certain roads or in zones; movement speed limits. The shape of the street and road network seems to be quite significant, the noise pollution index of which significantly depends on the linear building density and the size of the inter-main territory. Enlargement of inter-main territories is expedient from 25 to 100 hectares. At the same time, noise levels on the building line will increase by 2 - 4 dBA. The population living in conditions of discomfort will increase by 7-8%. A further increase in inter-main areas from 100 to 200 hectares leads to a reduction in noise by 2.5 - 3.5%. The increase in inter-main areas by 2 times from 25 to 50 hectares and further to 100 hectares leads to a decrease in capital investments in engineering and technical means of noise protection and annual economic damage per inhabitant by an average of 37%, and when enlarged from 100 to 200 hectares - by 25%. The influence of the size of inter-main territories on urban planning and economic indicators is shown in fig. 5.

Rice. 5. Influence of MMT dimensions on urban planning and economic indicators of noise pollution
a - population in the zone of noise pollution; b - economic damage from noise impact

The choice of reception of placement of buildings in the first row of buildings should be carried out taking into account noise levels on adjacent highways. Application in planning and development projects of residential areas and microdistricts of architectural and planning solutions that contribute to noise protection / placement of extended residential and utility buildings - screens in the first row of development, the choice of rational methods for placing buildings in the main area, concentrating in quiet areas of buildings with an increased number of storeys of a point type, preschool institutions of schools / will provide acoustic comfort for at least 80% of the population without the use of engineering and technical means of noise protection. The choice of types of buildings or block sections should be carried out depending on their placement in the building. The facades of the building that fall into the zone of acoustic discomfort should either have increased sound insulation of window openings, which will contribute to the necessary air exchange in the premises, or such an internal layout in which the living quarters would be turned to a quiet side. With mixed development, it is advisable to provide for the placement of lower buildings in the first row. Under the conditions of the historically established planning structure, which is formed around the central part, the main difficulty is the issue of normalizing the acoustic regime in areas of quarterly development that are not designed for increased traffic intensity. In such conditions, it is most rational: the creation of ring roads and alternate streets; arrangement of underground transport communications, partial or complete blocking of highways; formation of a network of one-way streets; - organization of non-stop traffic on the principle of a green wave. When placing buildings in the conditions of reconstruction, it is necessary, on the basis of the noise map of the quarter, first of all, to determine the zones where it is possible to build new residential buildings without taking noise protection measures. While maintaining quarterly development, internal redevelopment of residential premises should be envisaged in order to orient residential rooms in the direction “opposite to highways. If it is impossible to provide the required insolation, it is recommended to replace window blocks with windows with increased sound insulation. In the conditions of reconstruction, it may be necessary to develop individual designs of "quiet" windows. 3.2. In the general transport structure of the city, the movement of rail transport is characterized by a very noticeable emission activity. It is expedient to design railway lines bypassing the residential area for the passage of transit freight trains without entering the city. Sorting stations should be located outside the cities, and new technical stations and parks of reserve rolling stock, freight stations, yards and container yards - outside the residential area. Railway lines and stations are recommended to be separated from residential areas of settlements by a protective zone of at least 200 m wide for railway lines of categories I and II, at least 100 m for railway lines of categories III and IV, and at least 100 m from station tracks, counting from axis of the extreme railway track, it is necessary to use shielding structures. About 40% of the sanitary protection strip should be protective landscaping. Territories of sea and river cargo ports, mooring places for ships belonging to citizens, coastal bases and sports clubs for small fleets should be located in suburban areas at distances from the residential area justified by acoustic calculation. The distance from the ship's passage on waterways to the residential area is determined according to Table. 9. New airports and airfields must be located outside of populated areas. The smallest distance from the borders of the airfield to the residential area, taking into account the prospective development, is recommended to be taken according to Table. 10.3.3. Landscaping is one of the noise protection measures whose effectiveness is most evident in large-scale design. Green spaces help to reduce the intensity of noise only in those cases when they rise to their full depth with sufficient width above the beam connecting the source and the sound receiver / at least 2-3 m /. With dense landscaping, not only a shielding effect is provided, but additional noise attenuation is also created due to the absorption and reflection of sound inside the green mass. It is advisable to use special ordinary groupings of green spaces, the effect of which is most noticeable. In the current development, with a small width of landscaping strips, the effect of noise protection is insignificant, however, landscaping is used to create psychological comfort. It is important to decide the overall system of landscaping at the stage of the territorial CSE of the city's master plan. The effectiveness of landscaping is graphically presented in fig. 6. For noise protection purposes, both special alternating "green walls" are used, the effectiveness of which depends mainly on the reflection of sound, as well as large arrays of green spaces, the effectiveness of which is determined by dispersion and absorption. Multi-row structures achieve the greatest effect with a total width of up to 25 m, green areas - 25 m. Table 9

The levels of external noise of ships, at which the fulfillment of sanitary standards in residential areas during the daytime is ensured, dBA

The shortest distance from airports to residential areas

Rice. 6. Estimated costs for the formation of green spaces

To ensure the maximum efficiency of the strip, it is necessary that the height of mature trees exceed by 2 m or more the conditional line of the direct sound beam between the noise source and the calculated point. 3.4. The effectiveness of noise protection measures is the measure by which the need for them is compared with the possible reduction in the burden and reduction in their implementation as a result of the implementation of the measures. The effectiveness of noise protection measures will be high if, for a given need, a high effect is achieved as a result of carrying out an activity, the cost of which is insignificant. Thus, for zones with an uneven distribution of noise load and a heterogeneous residential structure, the efficiency value can be determined by the formula

, /24/

Where I B - load index; K - the total costs associated with the event; ΔI m e p is the index of level reduction. Estimated value of efficiency is given in table.11.

Rice. 7. Variants of noise-protective landscaping strips
Efficiency, dBA: a - 10 - 16; b - 2.4 - 2.8; in - 3.3 - 4

Table 11

The effectiveness of the use of noise protection products

Literature

Back to main rubricator: Soundproofing. Acoustics. FAQ

1. What is the main source of noise in settlements?

The source of noise in settlements, which has the greatest impact on residential development, is mainly transport.

Traffic noise has increased especially in recent decades. Cities, the planning and development of which took shape over the centuries, turned out to be unsuitable for the movement of a large number of vehicles along the streets, and residential buildings turned out to be not protected from traffic noise. A transport crisis is forming, which has become especially acute due to an unprecedented increase in the number of cars.

2. What are the sources of external noise in cities?

Cities are saturated with numerous noise sources, which can be conditionally divided into two large groups: individual sources and complex sources, consisting of a number of individual sources.

To individual noise sources include single vehicles, electrical transformers, intake or exhaust openings of ventilation systems, installations of industrial or energy enterprises, etc.

To complex noise sources include traffic on the streets or roads, train flows on the railway, industrial plants with multiple sources of noise, sports or playgrounds, etc.

Noise protection can be carried out both at the source of noise and along the path of its propagation. For the successful adoption of certain measures, it is necessary to know the noise characteristics of the sources.

3. What are the main methods for protection from external noise sources in cities?

Solving the problems of noise protection in cities in the presence of road transport requires a radical reconstruction of the street and road network and a change in the established principles of building blocks.

To protect against external noise sources in cities, the following main methods are used. The source of noise is engineering, technical, organizational and administrative. Along the path of noise propagation in the urban environment from the source to the protected object - urban planning and construction-acoustic. In the object of noise protection - structural and construction (improving the soundproofing qualities of building envelopes and structures) and planning.

4. What are the basic principles for protecting residential buildings from noise?

This is a complex problem that needs to be solved by architectural means by carrying out a complex of urban planning and construction-acoustic measures. When developing a feasibility study, a master plan for a city, a detailed planning of its districts, as well as development projects for residential microdistricts, it is necessary, first of all, to provide for urban planning measures to reduce noise in the building. This will allow in some cases to do without special construction and acoustic measures to protect against noise or reduce the cost of their implementation.

The most effective building-acoustic means of noise reduction include screens, noise-protective buildings and noise-protective windows.

5. What are the means by which noise suppression methods are implemented?

Firstly, this is a rational solution for the layout of the building in such a way that all the premises associated with the occurrence of this or that noise are concentrated in one place and removed from work and residential premises. So, in residential and public buildings, boiler rooms, machine rooms of elevators, elevator shafts and garbage chutes, pump rooms, rooms with fans, canteens, buffets, etc. should not be adjacent to living and working premises.

Living rooms of multi-storey residential buildings, dormitories and hotels, working rooms of administrative buildings, wards of hospitals and sanatoriums, classrooms and auditoriums of educational institutions should be separated from staircases by auxiliary premises (kitchens, bathrooms, corridors, etc.). Gymnasiums, workshops and other noisy rooms in educational institutions should not be located in the immediate vicinity of classes, auditoriums and laboratories.

The main means for protecting the premises of residential and public buildings from noise is the proper sound insulation of enclosing structures, which should ensure compliance with regulatory requirements for sound insulation. In many rooms of public buildings, it is advisable to install sound-absorbing linings, for example, in long rooms such as corridors in schools, hospitals, hotels, which prevents the spread of noise along them.

For noise reduction in typing bureaus, counting stations, computer centers, administrative buildings, restaurants, waiting rooms of railway stations and air terminals, shops, canteens, etc. sound-absorbing wall and ceiling coverings should be provided.

Most ventilation systems in public buildings require the use of silencers. Muffler designs can have different solutions. The simplest of them are arranged in the form of a channel lined inside with sound-absorbing material. In addition, lamellar ones are used, consisting of a number of parallel sound-absorbing plates separated by air gaps, honeycomb, chamber, etc.

Vibrations of various machines of engineering and sanitary equipment, transmitted to the structures on which it is installed, or to communications suitable for it, are the cause of structural noise that propagates along the building structures or even along the ground over long distances and is emitted in the form of airborne noise by fences in remote areas. quiet rooms.

Significant attenuation of this noise can be achieved by taking measures to prevent the spread of structural noise by installing units on vibration and sound insulators, made, for example, from spring or rubber shock absorbers.

It is also necessary to take measures to exclude hard contacts of the vibration and soundproof unit with external communications. To do this, rubber inserts should be provided in pipelines suitable for pumping units, tarpaulin or rubber inserts at the points of connection of air ducts to the fan, compensating loops on the power wires of electric motors, etc.

6. What are the urban planning methods and means of noise protection?

Significant noise reduction in residential areas can be ensured by strict compliance with the requirements of building codes and regulations for the planning and development of cities and other settlements. First of all, it is necessary to provide for a clear functional zoning of the territory with the separation of residential, medical and recreational zones from industrial and communal storage areas and main transport communications. Distances from the boundaries of industrial enterprises that are sources of external noise to residential buildings, hostels, hotels, preschool institutions, boarding schools, hospitals, sanatoriums, rest houses, boarding houses should not be less than those indicated in Table.

Table

7. Are there regulations for the placement of airfields in relation to settlements?

New airports and airfields must be located outside cities and other settlements. The smallest distance from the boundaries of the aerodrome to the boundaries of the residential area should be taken depending on the class of the aerodrome, the location of the runways and flight routes relative to the settlement according to Table 3.8

Table 3.8

The smallest distances from the borders of airfields to the borders of residential areas

The possibility of reducing the gaps between the airfield and residential areas compared to those indicated in Table. 3.8, subject to the implementation of special organizational and technical measures (reduction of night operations, special piloting techniques, etc.), as well as the use of noise-protective residential buildings, must be confirmed by calculation.

8. What are the standards for the location of transport routes in relation to residential development?

The distance from new railway lines and stations during new construction to the boundaries of residential areas without the use of special noise suppression equipment must be at least 200 m for category I and II railway lines, at least 150 m for category III and IV railway lines, and at least 100 m for station tracks, counting from the axis of the outermost railway track.

The distance from motor roads of categories I and II to the boundaries of residential areas in the absence of special noise suppression equipment must be at least 200 m, and from motor roads of categories III and IV - at least 100 m.

The distance from motor roads of categories I and II to the boundaries of land plots of sanatorium-and-spa institutions, hospitals and rest houses in the absence of special noise suppression equipment must be at least 500 m, and from motor roads of categories III and IV - at least 250 m.

The distance from the boundaries of the territory of sea and river ports to the boundaries of residential areas in the absence of special noise suppression equipment must be at least 100 m for the passenger area of ​​the port and at least 300 m for the cargo area of ​​the port.

It is advisable to provide for the combination of railway and highway routes. Streets and roads should be strictly differentiated in terms of purpose, speed of movement and composition of the traffic flow with the allocation of the main volume of freight traffic to specialized highways. Territories of residential areas and recreation areas should not be crossed by high-speed roads and freight traffic roads. High-speed roads in these territories, with appropriate justification, may be placed in recesses, tunnels and overpasses. The latter should be equipped with noise barriers or blind fences.

9. What are the principles of functional zoning of buildings, taking into account possible noise loads?

When designing a network of streets and roads, it is necessary to provide for the maximum possible enlargement of inter-main areas, a decrease in the number of intersections and other transport hubs, their replacement with T-shaped junctions, and the arrangement of smooth curvilinear junctions of streets. In the absence of special noise suppression means, residential buildings should be located at a distance of at least 150 m from the edge of the carriageway of express roads and freight traffic roads, at least 125 m from the main streets of citywide significance, at least 75 m from the main streets of district significance and at least 25 m from residential streets. It is advisable to design residential streets as dead ends, providing round areas for turning cars at the end of each dead end. The tracing of driveways should ensure the connection of residential and public buildings with the streets and prevent the through passage of vehicles through the territory of the microdistrict. When tracing the main streets and roads, one should use the noise-protective properties of the terrain - hills, ravines, beams, etc.

Functional zoning of residential territory should provide for the placement of trade enterprises, public catering, consumer services, public utilities, organizations and institutions of management, financing and communications enterprises in the zone adjacent to noise sources. Residential development, kindergartens, healthcare facilities, nursing homes must be located in the area farthest from noise sources.

In multi-storey buildings, the principle of a gradual increase in the number of storeys of residential buildings into the depth of the inter-main territory should be observed. Buildings of trade and public centers and service blocks located on the border of microdistricts along transport routes should be combined into single extended complexes. This solution allows the use of complexes of primary, daily and periodic maintenance facilities as effective noise barriers and at the same time significantly expands their scope, making it convenient for passing use when the population moves to and from work.

Premises of administrative, public and cultural and educational institutions with increased requirements for acoustic comfort - conference rooms, reading rooms, auditoriums of theaters, cinemas, clubs, etc. - should be placed on the side of buildings opposite from noise sources, separating them with corridors, foyers, cafe and buffet halls, utility rooms.

If it is necessary to place residential buildings on the border of microdistricts, along transport routes, special soundproof residential buildings . To ensure acoustic comfort in the territory of microdistricts, it is desirable to use compositional methods of grouping residential buildings based on the creation of a closed space. It is not recommended to use methods of grouping residential buildings with the disclosure of the space of the microdistrict in the direction of noise sources. For example, setting up residential buildings with their ends to the main street significantly expands the zone of acoustic discomfort.

10. In what cases is it effective to use noise protection strips of green spaces?

As an additional means of noise protection for low-rise residential buildings, recreation areas of microdistricts and groups of residential buildings, playgrounds for kindergartens and school sites, it is necessary to provide for the formation of special noise-protective strips of green spaces near noise sources. In order for such strips to have noticeable effectiveness, the crowns of the trees must be tightly adjacent to each other; the space under the crowns is recommended to be filled with green mass of shrubs. The width of the strips should be at least 10 m. Some increase in noise protection efficiency is achieved by dividing the strip in the longitudinal direction into several parts with gaps between them 3-4 m wide.

As green spaces, breeds of fast-growing large-sized trees with a densely branched, low-lying, dense crown should be used. Coniferous tree strips are the most effective and have a year-round effect. However, these trees do not grow well in urban environments, so they should be combined with hardwood trees.

11. What are noise barriers and how effective are they?

Screens. The concept of "screen" is usually referred to any obstacles in the path of noise propagation. Screens can serve as roadside retaining, enclosing and special protective walls, as well as artificial and natural elements of the terrain: earthen ramparts, embankments, hills, slopes of cuts, ravines, etc. Buildings can also serve as screens, in the premises of which sound levels of more than 40-50 dBA are allowed (buildings of consumer services enterprises, trade, public catering, utilities, etc.), residential and public buildings with enhanced sound insulation of external enclosing structures and with centralized or individual supply ventilation devices combined with noise silencers, as well as residential buildings in which utility rooms windows are located on the side of the noise source.

Table

Reducing the sound level by extended wall screens

12. What types of screens are particularly effective in combating traffic noise?

In the world practice of combating traffic noise, screens-walls, earthen ramparts and their combinations are most widely used. The required noise protection efficiency of screens is provided by varying their height, length, distance between the noise source and the screen. Reducing the sound level by the screen-wall at the calculated points located on the border of the sound shadow, i.e. on the continuation of a straight line connecting the acoustic center of the noise source with the top of the screen is about 5 dBA.

Therefore, to ensure higher acoustic efficiency, the top of the screen should rise above a straight line connecting the acoustic center of the noise source with the calculated point. When designing a screen-wall along a transport highway for approximate calculations, an increase in its efficiency with an increase in height can be taken equal to an average of 1.5 dBA per 1 m.

To increase the acoustic efficiency of the screen and reduce its height, it is recommended to take the minimum distance between noise sources and the screen, taking into account traffic safety and normal operation of the road and vehicles. Approximate values ​​for sound level reduction by extended wall screens at a height of 1.5 m from the surface level of the territory with a distance between the edge of the carriageway and the screen equal to 3 m are given in Table. 3.9. Such values ​​of acoustic efficiency are maintained at an angle of visibility of the shielded section of the street from the design point of at least 160°.

Currently, there are many designs of wall screens. The most common materials used for their construction are concrete and reinforced concrete. Steel, aluminum, various plastic materials, wood, etc. are also used. The required surface density of the screen-wall depends on the required acoustic efficiency and usually does not exceed 20 kg/m 2 .

13. What are the additional requirements for wall screens?

When designing wall screens, along with the required acoustic efficiency, it is necessary to meet a number of other requirements for them. Screens must be durable, resistant to atmospheric influences and the harmful effects of exhaust gases, withstand snow, wind and seismic loads. They must meet aesthetic requirements, be transportable, simple in construction, installation and operation. The design of individual elements of the screens should ensure their tight adjacency to each other to create an acoustically opaque screen.

Installing wall screens with an acoustically hard surface on one side of the noise source causes some increase in the sound level on the opposite side due to the contribution of the sound energy reflected from the screen. For example, when a screen-wall 5 m high is located along the road, the sound level on the opposite side of the road, depending on the distance from the curb, increases by 1-2 dBA. When installing wall screens with an acoustically hard surface along both sides of the road, the acoustic efficiency of the screens decreases by -5 dBA, depending on the distance between the screen and the traffic flow.

14. How can the acoustic efficiency of wall screens be improved?

To eliminate the undesirable effect of sound reflected from the wall surfaces, constructive solutions for screens with sound-absorbing linings have been developed. Sound-absorbing materials used for screen cladding must have stable physical, mechanical and acoustic performance throughout the entire period of operation, be bio- and moisture resistant, and not release harmful substances into the environment in quantities exceeding the maximum allowable concentrations for atmospheric air.

To protect the sound-absorbing material from moisture, it is necessary to provide a coating in the form of a film. From the outside, the screen with sound-absorbing lining must be protected with perforated sheets of aluminium, steel or plastic

The acoustic efficiency of wall screens to a certain extent depends on their shape. The most effective is the T-shaped cross profile of the screen.

15. What are the advantages and disadvantages of noise-protective earthen ramparts?

Earthen ramparts have a number of advantages over wall screens. To create them, as a rule, surplus soil is used, which is formed during the vertical planning of the building area and the construction of building foundations. The cost of building shafts is 2-3 times lower than the cost of building screens-walls. In addition, they give the highways a picturesque look. In the body of the shafts, garages, collectors and other structures can be located. However, due to the need for gentle slopes with slopes of 1:2 or 1:1.5, large areas are required for their placement. Therefore, the use of such screens is advisable mainly in suburban areas, where the main areas are not limited. In recent years, shaft structures with slope cladding with concrete or stone elements have been developed, which makes it possible to significantly increase the steepness of the slopes and, accordingly, reduce the width of the shafts.

16. What are the advantages of combined noise protection: recess + screen?

The placement of main streets and roads in recesses makes it possible to use their slopes as noise barriers. However, combined screens are more effective, consisting of a recess or an earthen rampart with a wall on top. In recent years, designs of screen-walls with open cavities have been developed for placing earth and planting climbing plants. From an aesthetic point of view, such screens are more acceptable than traditional wall screens.

17. How is noise protection achieved in special buildings?

In the conditions of modern cities with mass development of highway territories with multi-storey long buildings, in order to protect the population from traffic noise, it is most expedient to build special residential buildings, which are commonly called soundproof or soundproof.

According to the methods of noise protection, these buildings can be divided into two types. The first is houses with a special architectural and planning structure and a volumetric and spatial solution.

The second type of soundproof buildings provides for the protection of premises by increasing the sound insulation of external enclosing structures, the use of special ventilation devices combined with noise silencers. Since external fences consist of several elements - the outer wall, windows, balcony doors, the soundproofing properties of which differ sharply, their overall sound insulation is completely determined by the weakest elements, i.e. windows and balcony doors. Combined versions of noise-protective buildings are also possible.

To maintain the regulatory noise regime in residential areas, noise control should be carried out in three main areas:

At the source of noise - by engineering, organizational and administrative methods;

Along the path of noise propagation - urban planning and construction-acoustic methods;

In the object of noise protection - by constructive and construction methods.
External in relation to the residential area of ​​the city of Nyagan are rail transport, air transport and transit traffic flows.

Noise from railway transport occurs during the movement of trains and their processing at marshalling yards. Noise levels depend on the speed of movement, the load of the wagons, the general technical condition of the trains, the track, etc.

Taking into account the branching in the station area, the equivalent level of generated noise (taking into account the number of pairs of trains) is 80 dBA. Reducing the noise level to the standard value is achieved at a distance of 180-200 m.

In order to reduce the noise level, it is planned to create a sanitary protection zone along the railway track with noise-protective landscaping, and eliminate a number of access roads.

The airport, 10 km away from the city, does not affect the overall noise background.

Transit cargo flows are mainly directed to the bypass road, and also do not affect the overall noise background.

The main source of intracity noise is the backbone network of the city.

The calculation of the noise characteristics of traffic flows should be carried out in accordance with SNiP 11-12-77 "Protection from noise".

The sound level Later, in dBA, at the calculated point on the territory of the object protected from noise is determined by the formula:

LAter \u003d LAeq - Laras - L-Aekr - L-Azel

(in accordance with SNiP 11-12-77 "Protection from noise", clause 10.7) The project provides for the following urban development activities:

Functional division of transport highways;

Assigning the width of streets in accordance with the accepted classification of the road network;

Redistribution of traffic flows in connection with the creation of one-way streets, alternate streets, a bypass highway;

Landscaping of highway territories, creation of noise-protective green belts and others.

The enlargement of inter-main areas and the rational distribution of traffic loads on the road network can reduce noise by an average of 8 dBA.

The arrangement of alternate streets leads to noise reduction at hauls by 5-10 dBA, and at intersections by 8-25 dBA.

The organization of traffic allows to reduce the level of traffic noise by 2-10 dBA, and the regulation of the composition of traffic flows and the use of automatic control systems by 10-15 dBA.

Depending on the design of green spaces, the effectiveness of noise protection is 3-15 dBA, and the use of noise screens is 5-25 dBA.

Residential buildings used as noise barriers must have high soundproofing qualities of external enclosing structures.

structures and, first of all, windows, which can reduce the sound level by 18-45 dBA.

The dimensions of the sanitary protection zones from transformers to residential buildings are calculated taking into account the number and power of transformers at a voltage of 110-220 kV substations. (200-250 m).

The use of a set of noise protection measures makes it possible to improve the acoustic regime in residential premises.

PROTECTION AGAINST ELECTROMAGNETIC FIELD

To protect the population from the adverse effects of the electromagnetic field generated by overhead lines, it is necessary to organize a sanitary protection zone. The size of the zone for 110 kV power lines coincides with the size of the technical zone, i.e. equal to 5 m, for overhead lines - 330 kV -20 m.

Taking into account that the field strength in buildings can be reduced through planning solutions, the use of special building structures, it seems possible for the rational use of the sanitary protection zone from the television and radio center to divide its territory into a zone of a strict "construction" regime and a zone of "restriction".

The “strict” regime zone includes the technical territory of the radio transmitting facility.

The zone of "restrictions" can be used for urban development, provided that a set of measures aimed at reducing the level of field strength (rational planning, the use of special building structures, radio engineering methods) will ensure the recommended maximum permissible level of field strength in residential and other premises.

Noise regulation

Noise regulation is carried out in two directions: hygienic regulation and regulation of noise characteristics of machines and equipment (technological).

The current noise standards at workplaces are regulated by SanPiN 2.2.4 / 2.1.8.10-32-2002 “Noise at workplaces, in residential, public buildings and in residential areas” and GOST 12.1.003. "SSBT. Noise. General safety requirements”.

In accordance with SanPiN 2.2.4 / 2.1.8.10–32–2002, maximum permissible noise levels are normalized in two categories of noise standards: noise limit at workplaces; Noise limit control in the premises of residential, public buildings and on the territory of residential development.

Maximum permissible sound levels and equivalent sound levels in workplaces

For an approximate assessment of noise, the sound level is taken, determined by the so-called A scale of the sound level meter in decibels - dBA.

These documents establish the permissible noise levels in working rooms for various purposes. At the same time, zones with a sound level above 80 dBA are considered dangerous, they must be marked with special signs, and workers in these zones must be provided with personal protective equipment.

The maximum sound level for fluctuating and intermittent noise must not exceed 110 dBA. In areas with a sound pressure level of more than 135 dBA, even a short stay of people is prohibited.

For various production equipment and machines, the standards set the maximum levels of noise characteristics (machines, compressors, weaving and other equipment).

There are also standards that establish methods for determining noise characteristics.

The standards stipulate that the technical documentation indicates the noise characteristics of machines.

The fight against noise in production is carried out in a comprehensive manner and includes measures of a technological, sanitary-technical, therapeutic and prophylactic nature.

The classification of means and methods of noise protection is given in GOST 12.1.029–80 SSBT “Means and methods of noise protection. Classification”, SNiP II–12–77 “Noise protection”, which provide for noise protection by the following construction and acoustic methods:

a) soundproofing of enclosing structures, sealing the porches of windows, doors, gates, etc., arrangement of soundproof cabins for personnel; shelter of noise sources in casings;

b) installation of sound-absorbing structures and screens in rooms on the path of noise propagation;

c) the use of aerodynamic noise silencers in internal combustion engines and compressors; sound-absorbing linings in the air ducts of ventilation systems;

d) creation of noise protection zones in various places where people are located, the use of screens and green spaces.

Protection of workers from noise can be carried out both by collective means and methods, and by individual means.

Basic noise protection methods:

1. Source Noise Reduction

Causes: mechanical, aerodynamic, hydrodynamic and electromagnetic phenomena due to the design and nature of the machines, inaccuracies in manufacturing, etc.

To reduce noise at the source, use:

Replacement of percussion mechanisms with non-impact ones;

Use of low noise connections;

Replacing metal parts with plastic ones;

Replacement of rolling bearings with plain bearings

Changing operating modes;

Grease, etc.

These are the most effective measures, because. Dealing with noise after it occurs is more expensive and often ineffective.

2. Noise emission redirection

Appropriate orientation of installations in relation to workplaces or residential buildings.

This method is used in the case when a working device (machine, unit, installation) radiates noise in a direction. An example of such a device is a pipe for discharging compressed air into the atmosphere in the direction opposite to the workplace.