Introduction ................................................... .................................................. ................................. 3.

1. Trends to change the acoustic effects of transport 4

2. The state of the problem of reducing transport noise .............. 6

3. Limiting the impact of road noise 7

3.1. Reducing the intensity of motion, improvement of road construction and land use regulation ........................................ ................................. 7.

3.2. Soundproofing of buildings .................................................. ................................................ 12

4. The problem of reducing noise from rail transport 14

4.1. Reducing noise when the wheel and rail interaction ............................ 14

4.2. The noise of the freight car ............................................... ................................................. fifteen

4.3. Reducing vibration ................................................ .................................................. ....

5. Reducing the effect of noise from air transport .................. 20

5.1. Reducing the effects of noise generated by aircraft .. 20

5.2. Reducing the impact of noise (ground events) ........................... 22

5.3. Rules regulating land use near airports ................. 24

Conclusion ............................................................... .................................................. ...................... 27

List of used literature ............................................................. ............ 28.

Introduction

Noise pollution in cities is almost always local and mainly caused by means of transport - urban, railway and aviation. Already on the main highways of large cities noise levels exceed 90 dB And tend to strengthen annually by 0.5 dB, which is the greatest environmental hazard in areas of lively transport highways. According to medical studies, elevated levels of noise contribute to the development of neuropsychiatric diseases and hypertension. The fight against the noise in the central areas of cities is hampered by the density of the current building, due to which the construction is impossible noise protection Screens, expansion of highways and landing of trees that reduce noise levels on roads. Thus, the most promising solutions of this problem are to reduce their own noise of vehicles (especially tram) and use in buildings overlooking more busy highways, new noise absorbing Materials, vertical gardening of houses and triple glazals n. I am about it (with the simultaneous use of forced ventilation).

The special problem is an increase in the level of vibration in the city of x regions, the main source of which is transport. This problem is little studied, but it is undoubted that its value will increase. Vibration contributes to a more rapid wear and destruction of buildings and structures, but the most essential that it can adversely affect the most accurate technological processes. It is especially important to emphasize that the greatest harm to the vibration brings the industry to best industries and, accordingly, its growth can have a limiting impact on the possibilities of scientific and technological progress in cities.

1. Trends to change the acoustic effects of transport

In ancient Rome, there were legislative regulations governing the noise level created by vehicles of that time. But only recently, from the beginning of the 70s XX in. When developing the prospects for the development of transport began to take into account its environmental impact. Movement for the purity of the environment has become so powerful that many promising development in the field of transport were recognized as environmentally unwanted. This environmental revolution occurred not as the result of the public reaction to pollution in all its manifestations, but as a result of a combination of increased concerns and the public with the need to maintain environmental purity at least in the level of intensive development of means of transport and transport systems and urbanization. For example, transportation by road in the countries of the Organization for Economic Cooperation and Development (OECD) for 1960-1980. Ground 3 times, air - 2 times. The urban population of these countries increased by 50%, and the number of cities with the number of residents of more than 1 million people. doubled. During the same period, a lot of roads, airports and other large transport facilities were built.

With this development of transport and in not surprise that the noise pollution of the environment has constantly increased.

But it should be noted that since the late 70s, mainly due to experimental studies related to the limitation of noise created by individual means of transport and aircraft, and also partly as a result of the perfection of roads and sound insulation of buildings, the previously achieved level of transport noise has a tendency to stabilization. .

Given the tendency to reduce noise for the next few years, one can conclude about the impact of the relevant indicators. In OECD countries, more stringent requirements for noise restriction have been presented to cargo vehicles. New rules should lead to significant changes that will especially affect the part of the population, which is exposed to noise generated by heavy freight transport. In addition, in some countries, more advanced road design standards are introduced, as well as legislation providing people whose homes are subject to significant impact of transport noise, the right to demand adopting additional measures to sound insulation of residential premises.

It is estimated that in France by the 2000th year, the share of city inhabitants exposed to noise with a level of 65 dBA and higher, decreased to 13% compared with 16% in 1975. This is small, but, nevertheless, a significant decrease.

Providing more stringent measures to reduce vehicle noise in the source of its occurrence, one can expect further real decrease in the effects of noise per person. Back in 1971, in the UK, when developing a project of low noise heavy vehicles, it was recommended to proceed from the regulatory level of 80 dBA noise. Even if this project has demonstrated that modern technology allows you to implement a certain degree of noise reduction, being economically acceptable, still technical and political difficulties remain in the establishment of legislative measures that would contribute to the production of the design standards above. It is estimated that if it was possible to implement this technical policy, the number of people who are exposed to the noise of 65 dBA and more, significantly reduced.

As for the noise generated by civil aircraft, according to most studies, the implementation of measures to reduce its impact will take a sufficiently long time. This is due mainly by two reasons. First, the new generation of aircraft will be less noisy, secondly, all old-type aircraft that do not meet the modern regulatory requirements for noise will be removed by the end of the next decade. The rate of updating the existing aircraft fleet will depend, of course, from many factors, mainly from the pace of replacing aircraft with the samples of a new generation, as well as on the possible shift of the deadlines due to the expected increase in the general purpose aircraft park and the use of helicopters. Taking into account the listed factors in the forecast for the OECD countries, it is indicated that the United States will have a decrease in the number of people exposed to 65 dBA noise by approximately 50-70%, in Denmark by 35%, and in France, according to the results of the calculated assessment in relation to the five most important airports there will be a decrease in the area exposed to aviation noise, by 75%. Despite the fact that the number of people who will benefit from these events is slightly compared with the significantly large number of people exposed to ground transport noise unacceptably high levels, these measures are a significant step forward.

The quantitative indicators of the effects of the noise of railway transport in most countries remain in most part unchanged. It is assumed that in the foreseeable future, the state of affairs in this area will remain unchanged. However, there are areas where the noise of railway transport is the main source of irritation. Introduction Recently, high-speed trains and high-speed urban lines lead to expansion of zones exposed to new noise sources. Therefore, the living conditions of people can be improved if they take serious measures to reduce noise.

2. State of the problem of reducing transport noise

In the general case, the methods of reducing transport noise can be classified according to the following three areas: reduction of noise in the source of its occurrence, including withdrawal of vehicles and change their movement routes; reduce noise on the path of its distribution; Applying means of sound protection when perceiving sound.

The use of one or another method or their combination depends largely on the degree and nature of the required reduction of noise, taking into account both economic and operational restrictions.

Any attempt to regulate noise should begin with the establishment of sources of this noise. Despite the presence of a significant analogy of various sources, they are sufficiently unhappy with each other for three types of transport, - automotive, rail and air.

Noise is every unwanted sound for a person. Under normal atmospheric conditions, the speed of sound in the air is 344 m / s.

A sound field is a space area in which sound waves are distributed. When the sound wave is propagated, energy is transferred.

The noise level is measured in units expressing the degree of sound pressure - decibels (dB). This pressure is not perceived irrelevant. Noise at 20-30 dB is almost harmless to humans and is a natural sound background, without which life is impossible. As for the "loud sounds", then a permissible boundary rises to about 80 dB. The noise of 130 dB already causes a painful sensation in humans, and reaching 150 dB becomes intolerable for him. No wonder in the Middle Ages existed a penalty - "under the bell"; The bell ringing killed a man.

If in the 60s - 70s of the last century noise on the streets did not exceed 80 dB, then it currently reaches 100 dB and more. On many lively highways, even at night, the noise is below 70 dB, while at the sanitary standards it should not exceed 40 dB.

According to experts, the noise in big cities annually increases by about 1 dB. Bearing in view of the level already achieved, it is easy to imagine the very sad consequences of this noise "invasion".

Depending on the level and nature of noise, its duration, as well as from the individual characteristics of a person, the noise can have various actions on it.

Noise, even when he is small, creates a significant burden on the human nervous system, having a psychological impact on him. This is especially often observed in human mental activities. Weak noise affects people. The reason for this may be: age, state of health, type of labor. The impact of noise depends on the individual attitude towards it. So, the noise produced by the person himself does not bother him, while a small extraneous noise can cause a strong irritating effect.

The absence of the necessary silence, especially at night, leads to premature fatigue. High level noises can appear good soil for the development of insomnia, neuroses and atherosclerosis.

Under the influence of noise from 85 - 90 dB, the hearing sensitivity at high frequencies is reduced. For a long time, people complain about malaise. Symptoms - headache, dizziness, nausea, excessive irritability. All this is the result of work in noisy conditions.

11. Activities to combat noise problems.

Noise protection products are divided into collective and individual protective equipment.

Measures regarding noise reduction should be provided at the design stage of industrial facilities and equipment. Special attention should be paid to the removal of noisy equipment into a separate room, which allows to reduce the number of employees in an increased noise level and measures regarding noise reduction with minimal funds,

equipment and materials. The reduction of noise can be achieved only by defkering all the equipment with a high level of noise.

The work on the monkeying of the active production equipment in the room is beginning with the compilation of noise maps and spectra of noise, equipment and industrial premises, on the basis of which the decision is made regarding the direction of work.

Fighting noise in the source of its occurrence -the most effective way to combat noise. Low noise mechanical transmissions are created, methods for reducing noise in bearing nodes, fans are being developed.

Architectural and planning aspect of collective protection against noiserelated to the need to account for noise protection requirements in projects planning and building cities and microdistricon. It is planned to reduce the noise level by using screens, territorial gaps, noise protection structures, zoning and zoning sources and protection objects, protective landscaping.

Organizational and technical means of protection against noiserelated to the study of the processes of noiseing industrial installations and aggregates, transport machines, technological and engineering equipment, as well as with the development of more advanced low-noise design solutions, the norms of extremely permissible levels of noise of machines, aggregates, vehicles, etc.

Acoustic remedies for noise protectionthey are divided into soundproofing, sound absorption and silencers of noise.

12. Electromagnetic field and man.

The electromagnetic field is a special form of matter, which is interrelated electrical and magnetic fields.

The effect of electromagnetic radiation on the human body is mainly determined by energy absorbed in it. It is known that radiation falling on the human body is partially reflected and partially absorbed in it. The absorbed part of the energy of the electromagnetic field turns into, thermal energy. This part of the radiation passes through the skin and propagates in the human body, depending on the electrical properties of tissues (absolute dielectric constant, absolute magnetic permeability, specific conductivity) and the oscillation frequency of the electromagnetic field.

In addition to the thermal effect, electromagnetic radiation cause polarization of human body tissues, moving ions, macromolecule resonance and biological structures, nervous reactions and other effects.

It follows from the above that when the human irradiation with electromagnetic waves in the tissues of its body, the most complex physico-biological processes occur, which may cause violation of the normal functioning of both individual organs and the body as a whole.

People working under excessive electromagnetic radiation are usually quickly tired, complain of headaches, general weakness, pain in the heart. They increase sweating, irritability increases, becomes anxious sleep. Separate individuals appear in prolonged exposure, there is a decrease in memory, the trophic phenomena (hair loss, nail fragility, etc.) are observed.

Noise influence is called one of the main hazards in modern megalopolis.

The Public Chamber and Human Rights Council (LTF) proposed to the Government to develop a comprehensive program to combat noise in large cities, said the newspaper Izvestia. According to the GPBU "Mosecomonitoring", about 60% of Moscow territory is subject to a constant noise effect exceeding the standards. Most citizens suffer from automotive, railway and aviation noises.

"Noise is one of the main environmental hazards in modern megalopolis. Noise pollution causes irregular buildings, industrial enterprises, transport, repair work. We have a fines in the legislation for violation of the noise levels, there are laws about silence, but noise pollution is a comprehensive The problem and the approach to its solution should be appropriate. Many do not make aware that acoustic pollution not only gives discomfort, but also makes tremendous harm to the health of people, provokes chronic diseases, "said the responsible secretary of the SCC, Yana Lantratova.

According to women, children suffer most from noise. Meanwhile, in other states the problem has long been solved, including with the help of fines.

"The worst thing is that children suffer from him. Abroad, it was long ago concerned with this problem and its decision with the help of high fines, special marking of vehicles and other ways," said Lantratov.

Scientists agree with the Public Chamber and HCH - noise can lead to serious violations in the work of the body.

"Noise affects the brain to work - on the degree of attention, concentration, fatigue, accuracy of functions by the operator. The influence of the low-frequency roe is very adversely affected. Especially if we are talking about the frequencies close to the alpha rhythm of a person," said the scientific secretary of the institute notes physiology them. I.P. Pavlova RAS Alexander Chuikin.

Among the proposals of the SCC and Public Chamber are the installation of additional noise protection screens along the roads and railway tracks, as well as an increase in fines for the violators of the regime - in particular, motorcyclists.

"The program is definitely needed. And Moscow, and Petersburg are very noisy cities. All major cities suffer the same. For example, in the West you will never see a car from which very loud music comes. The driver will immediately pay such a penalty that No longer in life will not increase the sound. Well, and, of course, this is another question of inner culture.

So you need to put the screens, fined the motorcyclists, "said the head of the physiology of the institute of physiology. I.P. Pavlova RAS Nikolay Nikitin.

The researcher responds that noises can have an extremely negative psychogenic effect on a person.

"The noise of increased volume destroys the auditory apparatus. Road noises do not reduce the rumor, but they negatively affect the nervous system. Especially if it is a continuous noise. At a minimum, it causes irritation, all kinds of mental reactions and even disorders. And advertising of any supermarkets at the metro station ? All day, these loud sounds annoying people. I think for such things you need to seriously punish the ruble. We conducted an experiment: a person was put on the site and began to move a sound signal by him in the sphere. And the man began to hear, swing, his center of gravity shifted together With a change in the position of the sound source. Moreover, the reaction was involuntary, "explains Nikitin.

Earlier it was reported that residents of the Moscow Region Kotelnikov complained about the noise during the repair of roads at night. According to the deputy head of the city administration Konstantin Karpova, the road builders independently decided to carry out repair work at night, for this it faces a fine.

The strongest factors that can have a negative impact on a person belongs to noise. Noise is one of the forms of harmful effects on the environment. The environmental pollution occurs as a result of an invalid exceeding sound oscillation levels over natural background. From an ecological point of view, in natural conditions, the noise becomes not just unpleasant for hearing, but also leads to serious physiological consequences for a person.
The basis of the occurrence of noise is the mechanical oscillations of elastic tel. In the air layer, directly adjacent to the surface of the fluctuating body, there are thickening (compression) and the vacuum, which alternate in time and apply to the side in the form of an elastic longitudinal wave. This wave reaches the human ear and causes periodic pressure fluctuations near it, which affect the auditory analyzer.
The person's ear can perceive sound fluctuations with a frequency in the range from 1b to 20,000 Hz. All noise is made to divide on low-frequency (below 350 Hz), mid-frequency (350-800 Hz) and high-frequency (above 800 Hz). With a low frequency, the oscillation sound is perceived as low, with a greater frequency - as high. High sounds have a more adverse effect on the rumor and on the entire human body than low, therefore noise, in the spectrum of which high frequencies prevail, is more harmful than noise with a low-frequency spectrum.
Sound volume, or noise level depends on sound pressure level. The unit of measurement of sound pressure is decibel (dB) - a tenth of the decimal logarithm of the intensity of sound energy to its threshold value. The choice of logarithmic scale is caused by the fact that the human ear has an extremely large range of sensitivity to change the intensity of sound energy (in Yu10), which corresponds to a change in the noise level of only 20 to 120 dB on a logarithmic scale. The maximum range of audible sounds for a person is from 0 to 170 dB (Fig. 70).
Permanent or intermittent noise is estimated at the level of rms pressure in the spectrum areas corresponding to

Fig. 70. Noise from various sources (dB)

frequencies 63, 125, 250, 500, 1000, 2000, 4000, 8000 Hz. An indicative assessment of noise can be carried out at the sound levels measured on the noiseomer scale (dB a).
The non-permanent noise is estimated at the equivalent sound levels, under which the average sound level of non-permanent noise, which has the same impact on humans, as the constant noise of the same level.
Natural natural sounds on the environmental well-being of a person are not reflected: the rust of foliage and the measuring noise of the sea surf correspond to about 20 dB. Sound discomfort creates anthropogenic sources of noise with high (more than 60 dB) noise levels that cause numerous complaints. Noise levels less than 80 dB do not cause risks for hearing, at 85 dB, some hearing deterioration begins, and at 90 dB - a serious impairment of hearing; At 95 dB, the probability of hearing loss is 50%, and at 105 dB, the hearing loss is noted with almost all persons who have undergone noise. The noise level of 110-120 dB is considered to be a painful threshold, and over 130 dB - is a destructive limit for the hearing organ.
The human hearing body can adapt to some permanent or repeating noise (auditory adaptation). But this adaptability cannot protect against loss of hearing, but only temporarily postponing its offensive. Under the conditions of urban noise there is a constant voltage of the auditory analyzer. The ego causes an increase in the threshold of hearing for 10-25 dB. Noise makes it difficult for speech intelligibility, especially with noise level of more than 70 dB.
Currently, more than half of the population of Western Europe lives in areas with noise level 55-65 dB: in France - 57% of the population, in the Netherlands - 54%, Greece - 50%, Sweden - 37%, Denmark and Germany - 34%. On the territory of Moscow, the zone with periodic exceeding the permissible level of noise reach 60%.
Noise as an environmental factor leads to an increase in fatigue, a decrease in mental activity, neurosis, growth of cardiovascular diseases, noise stress, impairment of vision, etc. Permanent noise is able to cause a surge of the central nervous system, due to which residents of the noisy areas of the city, by an average of 20%, more often suffer from cardiovascular diseases and by 18-23% - atherosclerosis and impaired nervous system. Especially negatively noise affects the functional state of the heart system in children.
Excessive street noise is the cause of 80% of the migraine in the inhabitants of France, about 50% of memory disorders and the same number of spoiled characters.
The noise contributes to the development of neuroses, which suffer from the fourth part of men and the third part of the UK women. According to French psychiatrists, the fifth of all psychiatric patients have lost their mind as a result of strong noise. In New York, there is a lagging towards children in growth and mental development due to excessive noise.
Noise in big cities reduces human life expectancy. According to Australian researchers, noise by 30% is the cause of aging citizens, reducing the life expectancy for 8-12 years, pushes people to violence, suicide, murder.
Currently, noise irritations relate to important reasons for sleep disorder, while such violations affect the effectiveness of recreation and can lead to the state of chronic fatigue, drowsiness with all the consequences arising from here for performance and susceptibility to disease. At night, the noise is capable of cumulatively accumulate. Night noise in 55 dB causes the same physiological effects as daytime noise of 65 dB; Noise in 65-67 dB, repeating over 5 times per night, has significant harm to human health. The threshold value of the noise level capable of causing a sleep disorder is depending on different reasons on average 40-70 dB: in children it reaches 50 dB, in adults - 30 dB, and in the elderly people are significantly lower. The noise has the greatest concern on people engaged in mental labor, compared to physically working.
Depending on the origin, the noise of the household, production, industrial, transport, aviation, the noise of the street movement is distinguished, etc. Household noise occurs in residential areas from the work of television and radio equipment, household appliances and behavior of people. Production noise is created in the production facilities working mechanisms and machines. The source of industrial noise is industrial enterprises, among which energy installations are allocated, compressor stations, metallurgical plants, construction enterprises, creating a high level of noise (more than 90-100 dB). A slightly smaller noise occurs when the operation of machine-building plants (80 dB), printing houses, sewing factories, woodworking plants (72-76 dB).
Transportation is created by motor, wheels, brakes and aerodynamic features of vehicles. The noise level created by the operation of automobile transport (buses, passenger and trucks) is 75-85 dB. Railway transport is able to raise noise to 90-100 dB. The strongest noise is aviation - it is created by the operation of the engine and the aerodynamic characteristics of the aircraft - up to 100-105 dB over the air transport route. In the areas of airports, the number of stillbirth and congenital anomalies is statistically significantly significantly increased. Aviation noise also leads to an increase in the number of mental disorders. The maximum allowable level of this noise at the surface of the Earth is determined in 50 dB.
The volunteer's noise is a totality of transport noise and all the sounds of the street (whistles of traffic controllers, rustling of pedestrian steps, etc.).
The transport noise arising from the movement of motor vehicles is up to 80% of the total city noise. In recent decades, the noise level in large cities increased by 10-15 dB. Transport flows on district highways near major cities in peak hours reach 2,000 cars per hour, at urban highways - up to 6000 cars per hour. Increasing noise in large cities is associated with increasing power and capacity of transport, increasing engine speed, with the introduction of new engines, etc. The most noisy city in the world is Rio de Janeiro, the noise level in one of its districts (Kapabana) significantly exceeds 80 dB. The noise level in Cairo is the largest city of Africa and the Middle East - is 90 dB, and at the main streets of the city reaches 100 dB. On the roads of Moscow, St. Petersburg and other major cities of Russia, the noise level from transport during the daytime reaches 90-100 dB and even at night in some areas does not fall below 70 dB. In general, Russia in Russia is about 35 million people, which is 30% of the urban population, are subject to the substantial effects of transport noise.
To protect the population from the harmful influence of urban noise, it is necessary to regulate its intensity, spectral composition, time and other parameters. The norms of permissible levels of external noise from various sources are being developed.
In hygienic rationing, such a noise level is established as permissible, the action of which for a long time does not cause changes in the complex of physiological indicators reflecting the reactions of the most sensitive to the noise of the body's systems.
Regulatory levels of sound pressure and sound levels for premises of residential and public buildings, territories of micro-district, recreation places are established in accordance with the sanitary standards of permissible noise (Table 42).
The permissible noise of street movement near the walls of houses should not exceed 50 dB and at night 40 dB, and the overall noise level in residential premises is 40 dB during the day and 30 dB at night.
Permissible levels of noise in the territories of various
economic purposes
Table 42.

As permissible parameters of aviation noise on the ground in a residential building conditions, maximum levels of 75 dB sounds at night and 85 dB during the day and equivalent levels of 55 dB sounds at night and 65 dB during the daytime.
The idea of \u200b\u200bplacing the sources of noise and the spread of noise in the city gives a noise map. On this map, you can judge the state of the noise regime of the streets, neighborhoods, the entire city territory. The city's noise map makes it possible to regulate the noise level on the residential territory of the city, and also serves as the basis for the development of complex town planning measures to protect the residential building from noise.
When drawing up a map of the noise of the city, the conditions of transportation of transport on the trunk streets, the intensity and speed of movement, the number of units of cargo and public transport in the stream, placement of industrial facilities, transformer substations, external transport, the cost of housing stock, etc. The card must contain information about the types of buildings of buildings, about the placement of medical and preventive institutions, research institutes, parks. The city's map shows existing noise sources with their levels obtained by torture measurements.
The map can be judged on the state of the noise regime on the highways and the territory of the residential building directly adjacent to them, to identify the most dangerous areas in acoustic terms. Maps of different years allow us to judge the effectiveness of activities aimed at reducing noise.
In fig. 71 Presents a fragment of a noise map of one of the Karaganda regions.

Fig. 71. Fragment of the noise map of the city:
1-6 - city streets; Noise levels: i - 80 dB A; II - 76 dB A;
III - 65 dB A; IV - 79 dB A; V - 78 dB A; Vi - 70 dB a

The presented area mainly affect the transport highways (streets 1-2, 4-6) with high intensity of motion, especially freight transport. The territory, surrounded by these streets, is exposed to the noise of large intensity (78-80 dB a). Even at a distance of 100 m from the roadway, the noise intensity reaches 65 dB A.
Analysis of the noise card shows that the permanent growth of the car park in the presence of a large number of narrow streets and sidewalks, the lack of the necessary improvement and insulation of microdistrics and blocks from penetrating transport noise has created prerequisites for an increased noise background of the city. To ensure the acoustic comfort of the population, the width of the highway with such an intensive movement of transport must be at least 100-120 m.
The noise map makes it possible to identify the complex of factors affecting the acoustic regime, to recommend the rational placement of the functional zones of the city, which allows to weaken or completely eliminate the influence of the main sources of noise.
The most frequent causes of the level of noise are: insufficient territorial gap to ensure the noise protection of settlements, the territories of the mass recreation, resorts, therapeutic centers; violation of the regulatory documents or the lack of accounting for sanitary standards in the development and design of the main road and railway trails, airport locations; increasing the noise level from year to year due to the lack of new silent modes of transport, increase the capacity of jet engines of aircraft; High cost of sound protection structures, lack of technical and economic development in this area.
These causes are mainly determined by a promising set of noise protection measures.
The method of reducing noise on the path of its distribution is the greatest importance, including various activities: the organization of the necessary territorial gaps between sources of external noise and zones of various economic purposes with a normalized noise regime, rational planning and development of the territory, the use of terrain relief as natural natural screens, noise protection .
Special territorial gaps make it possible to significantly reduce the noise level in residential territories. Sanitary standards and rules provide for the creation of sanitary protection zones between production facilities, transport highways, airfields, marine and river ports and residential buildings. Within sanitary protection zones, the shielding buildings of non-residential purpose are allowed, in which noise level is allowed 55-60 dB and the noise properties of houses-screens are quite high. Especially effective extensive buildings like shopping rows. They reduce the transport noise by 20-30 dB A and reliably protect intra-quartered territory. The buildings of the screens can be placed garages, workshops, reception points of household service enterprises, dining rooms, cafes, restaurants, atelier, hairdressers, etc. You should not only be placed in this area of \u200b\u200bthe pharmacy, libraries and other institutions in which noise level should not exceed 40 dB A.
The optimal planning and development of the territory contributing to the reduction of noise levels provides for a rational trace of transit highways, laying them outside the towns and recreation places; The device of ring and semi-rival roads and bypass rail lines in suburban areas of cities with a population of more than 250 thousand people; localization of intensive sources of noise in the territory under consideration and separation of residential areas, mass recreation areas, tourism from industrial and factory zones and transport sources; The removal of the most powerful sources of noise beyond the territory under consideration or, on the contrary, deposancy of housing from the zone of increased noise.
The motorways I and II categories and railway lines, creating respectively equivalent noise level 85-87 and 80-83 dB A, should not cross the territory of the suburban zone, where forest parks, holiday homes, boarding houses, children's camps and medical institutions and sanatoriums, universities are placed Research institutes. Recreation homes need to be placed at a distance of at least 500 meters from roads and industrial enterprises and 1 km from the railway.
Industrial enterprises, areas or production areas that are noise sources of elevated levels (70-80 dB a), should be separated from residential buildings with protective zones and are placed taking into account the dominant direction of the wind. At the same time, other factors adhere to the environment are taken into account.
Industrial enterprises, equivalent noise levels of which are less than 60 dB A, can be located in industrial and residential areas if they are not sources of other negative effects.
Airports should be placed outside the city, outside the recreation areas. The distance from the borders of the runway of the airfield to the borders of the residential territory depends on the class of the airfield, intersection of the flight track with residential territory, and may vary in the range from 1 to 30 km.
To reduce noise in urban planning practice, natural shielding structures are used, based on the use of terrain - recesses, embankments, ravines, etc.
Exceptional ability to delay and absorb noise impacts have woody and shrubs planted along the motorways. The multi-row strip of wood-shrub planting with a height of 5-6 m is able to significantly reduce the noise level; The greatest effect is available broadbands - with a strip width of 25-30 m, a decrease in noise level is observed by 10-12 dB A. However, in the winter period, the protective function of green plantings is reduced by 3-4 times.
When developing projects for detailed planning and building buildings, the protective effect can be achieved by zoning the residential area. In the zone directly adjacent to the highway, it is necessary to have a low building of non-residential destination, in the next zone - low-rise living building, hereinafter - the living building of high floors and in the most distant zone - children's institutions, schools, polyclinics, hospitals, etc.
A significant reduction in noise level is achieved with a closed construction type (Table 43).
Efficiency of gas-noise development and relief elements
Table 43.

Type of construction	Reduced level
	pollution,%	noise DB A.
Solid nine-story perimeter construction	63	20-30
Perimetral nine-story building with arches	40	/>12-20
Perimetral nine-story building with ruptures	25	10-26
P-shaped nine-story building	50	18-22
Free nine-story building (80-120 m from the highway)	40	12-18
Location highway on mound	25	11
Location of the highway in the excavation	68	15

In the conditions of mass development of primary territories, multi-storey extended buildings for the protection of the population from transport noise are advisable to build special types of residential buildings. The bedrooms and most residential rooms must be oriented towards the yard, and the windows of common rooms without sleeping places, kitchens, flight-elevator nodes, veranda and galleries - towards the main streets. Not only the planning of apartments, but also noise-proof windows with triple glazing and a high degree of sealing, which will ensure special bounds will help the silence in the house. Massive walls and soundproofing plates are effective for eliminating noise from adjacent rooms.
In addition to urban planning activities, a complex of other events is used to eliminate noise pollution - installation on the equipment of soundproofing housings, emission silencers. In some countries, in particular, in Germany, there are noise protection zones in Germany, on many military and civil airfields that take reactive aircraft, the intensity of flights is limited until the prohibition of night flights, restrictions were introduced for supersonic aircraft over time, height, speed. For wheel-rail transport, technical methods of reduction of noise are applied: sound-absorbing wheeled blends, replacing boom brakes on disk et al. In some parts of the highways, a noise absorbing asphalt was used, having high porosity due to larger amount of emptiness (25% instead of 6% in conventional asphalt ). This made it possible to reduce the noise level on the roads of Germany by 4-6 dB.
The strongest factors that can have a negative impact on a person belongs to noise. Noise is one of the forms of harmful effects on the environment. The environmental pollution occurs as a result of an invalid exceeding sound oscillation levels over natural background. From an ecological point of view, in natural conditions, the noise becomes not just unpleasant for hearing, but also leads to serious physiological consequences for a person.
The basis of the occurrence of noise is the mechanical oscillations of elastic tel. In the air layer, directly adjacent to the surface of the fluctuating body, there are thickening (compression) and the vacuum, which alternate in time and apply to the side in the form of an elastic longitudinal wave. This wave reaches the human ear and causes periodic pressure fluctuations near it, which affect the auditory analyzer.
The person's ear can perceive sound fluctuations with a frequency in the range from 1b to 20,000 Hz. All noise is made to divide on low-frequency (below 350 Hz), mid-frequency (350-800 Hz) and high-frequency (above 800 Hz). With a low frequency, the oscillation sound is perceived as low, with a greater frequency - as high. High sounds have a more adverse effect on the rumor and on the entire human body than low, therefore noise, in the spectrum of which high frequencies prevail, is more harmful than noise with a low-frequency spectrum.
Sound volume, or noise level depends on sound pressure level. The unit of measurement of sound pressure is decibel (dB) - a tenth of the decimal logarithm of the intensity of sound energy to its threshold value. The choice of logarithmic scale is caused by the fact that the human ear has an extremely large range of sensitivity to change the intensity of sound energy (in Yu10), which corresponds to a change in the noise level of only 20 to 120 dB on a logarithmic scale. The maximum range of audible sounds for a person is from 0 to 170 dB (Fig. 70).
Permanent or intermittent noise is estimated at the level of rms pressure in the spectrum areas corresponding to

Fig. 70. Noise from various sources (dB)

frequencies 63, 125, 250, 500, 1000, 2000, 4000, 8000 Hz. An indicative assessment of noise can be carried out at the sound levels measured on the noiseomer scale (dB a).
The non-permanent noise is estimated at the equivalent sound levels, under which the average sound level of non-permanent noise, which has the same impact on humans, as the constant noise of the same level.
Natural natural sounds on the environmental well-being of a person are not reflected: the rust of foliage and the measuring noise of the sea surf correspond to about 20 dB. Sound discomfort creates anthropogenic sources of noise with high (more than 60 dB) noise levels that cause numerous complaints. Noise levels less than 80 dB do not cause risks for hearing, at 85 dB, some hearing deterioration begins, and at 90 dB - a serious impairment of hearing; At 95 dB, the probability of hearing loss is 50%, and at 105 dB, the hearing loss is noted with almost all persons who have undergone noise. The noise level of 110-120 dB is considered to be a painful threshold, and over 130 dB - is a destructive limit for the hearing organ.
The human hearing body can adapt to some permanent or repeating noise (auditory adaptation). But this adaptability cannot protect against loss of hearing, but only temporarily postponing its offensive. Under the conditions of urban noise there is a constant voltage of the auditory analyzer. The ego causes an increase in the threshold of hearing for 10-25 dB. Noise makes it difficult for speech intelligibility, especially with noise level of more than 70 dB.
Currently, more than half of the population of Western Europe lives in areas with noise level 55-65 dB: in France - 57% of the population, in the Netherlands - 54%, Greece - 50%, Sweden - 37%, Denmark and Germany - 34%. On the territory of Moscow, the zone with periodic exceeding the permissible level of noise reach 60%.
Noise as an environmental factor leads to an increase in fatigue, a decrease in mental activity, neurosis, growth of cardiovascular diseases, noise stress, impairment of vision, etc. Permanent noise is able to cause a surge of the central nervous system, due to which residents of the noisy areas of the city, by an average of 20%, more often suffer from cardiovascular diseases and by 18-23% - atherosclerosis and impaired nervous system. Especially negatively noise affects the functional state of the heart system in children.
Excessive street noise is the cause of 80% of the migraine in the inhabitants of France, about 50% of memory disorders and the same number of spoiled characters.
The noise contributes to the development of neuroses, which suffer from the fourth part of men and the third part of the UK women. According to French psychiatrists, the fifth of all psychiatric patients have lost their mind as a result of strong noise. In New York, there is a lagging towards children in growth and mental development due to excessive noise.
Noise in big cities reduces human life expectancy. According to Australian researchers, noise by 30% is the cause of aging citizens, reducing the life expectancy for 8-12 years, pushes people to violence, suicide, murder.
Currently, noise irritations relate to important reasons for sleep disorder, while such violations affect the effectiveness of recreation and can lead to the state of chronic fatigue, drowsiness with all the consequences arising from here for performance and susceptibility to disease. At night, the noise is capable of cumulatively accumulate. Night noise in 55 dB causes the same physiological effects as daytime noise of 65 dB; Noise in 65-67 dB, repeating over 5 times per night, has significant harm to human health. The threshold value of the noise level capable of causing a sleep disorder is depending on different reasons on average 40-70 dB: in children it reaches 50 dB, in adults - 30 dB, and in the elderly people are significantly lower. The noise has the greatest concern on people engaged in mental labor, compared to physically working.
Depending on the origin, the noise of the household, production, industrial, transport, aviation, the noise of the street movement is distinguished, etc. Household noise occurs in residential areas from the work of television and radio equipment, household appliances and behavior of people. Production noise is created in the production facilities working mechanisms and machines. The source of industrial noise is industrial enterprises, among which energy installations are allocated, compressor stations, metallurgical plants, construction enterprises, creating a high level of noise (more than 90-100 dB). A slightly smaller noise occurs when the operation of machine-building plants (80 dB), printing houses, sewing factories, woodworking plants (72-76 dB).
Transportation is created by motor, wheels, brakes and aerodynamic features of vehicles. The noise level created by the operation of automobile transport (buses, passenger and trucks) is 75-85 dB. Railway transport is able to raise noise to 90-100 dB. The strongest noise is aviation - it is created by the operation of the engine and the aerodynamic characteristics of the aircraft - up to 100-105 dB over the air transport route. In the areas of airports, the number of stillbirth and congenital anomalies is statistically significantly significantly increased. Aviation noise also leads to an increase in the number of mental disorders. The maximum allowable level of this noise at the surface of the Earth is determined in 50 dB.
The volunteer's noise is a totality of transport noise and all the sounds of the street (whistles of traffic controllers, rustling of pedestrian steps, etc.).
The transport noise arising from the movement of motor vehicles is up to 80% of the total city noise. In recent decades, the noise level in large cities increased by 10-15 dB. Transport flows on district highways near major cities in peak hours reach 2,000 cars per hour, at urban highways - up to 6000 cars per hour. Increasing noise in large cities is associated with increasing power and capacity of transport, increasing engine speed, with the introduction of new engines, etc. The most noisy city in the world is Rio de Janeiro, the noise level in one of its districts (Kapabana) significantly exceeds 80 dB. The noise level in Cairo is the largest city of Africa and the Middle East - is 90 dB, and at the main streets of the city reaches 100 dB. On the roads of Moscow, St. Petersburg and other major cities of Russia, the noise level from transport during the daytime reaches 90-100 dB and even at night in some areas does not fall below 70 dB. In general, Russia in Russia is about 35 million people, which is 30% of the urban population, are subject to the substantial effects of transport noise.
To protect the population from the harmful influence of urban noise, it is necessary to regulate its intensity, spectral composition, time and other parameters. The norms of permissible levels of external noise from various sources are being developed.
In hygienic rationing, such a noise level is established as permissible, the action of which for a long time does not cause changes in the complex of physiological indicators reflecting the reactions of the most sensitive to the noise of the body's systems.
Regulatory levels of sound pressure and sound levels for premises of residential and public buildings, territories of micro-district, recreation places are established in accordance with the sanitary standards of permissible noise (Table 42).
The permissible noise of street movement near the walls of houses should not exceed 50 dB and at night 40 dB, and the overall noise level in residential premises is 40 dB during the day and 30 dB at night.
Permissible levels of noise in the territories of various
economic purposes
Table 42.

As permissible parameters of aviation noise on the ground in a residential building conditions, maximum levels of 75 dB sounds at night and 85 dB during the day and equivalent levels of 55 dB sounds at night and 65 dB during the daytime.
The idea of \u200b\u200bplacing the sources of noise and the spread of noise in the city gives a noise map. On this map, you can judge the state of the noise regime of the streets, neighborhoods, the entire city territory. The city's noise map makes it possible to regulate the noise level on the residential territory of the city, and also serves as the basis for the development of complex town planning measures to protect the residential building from noise.
When drawing up a map of the noise of the city, the conditions of transportation of transport on the trunk streets, the intensity and speed of movement, the number of units of cargo and public transport in the stream, placement of industrial facilities, transformer substations, external transport, the cost of housing stock, etc. The card must contain information about the types of buildings of buildings, about the placement of medical and preventive institutions, research institutes, parks. The city's map shows existing noise sources with their levels obtained by torture measurements.
The map can be judged on the state of the noise regime on the highways and the territory of the residential building directly adjacent to them, to identify the most dangerous areas in acoustic terms. Maps of different years allow us to judge the effectiveness of activities aimed at reducing noise.
In fig. 71 Presents a fragment of a noise map of one of the Karaganda regions.

Fig. 71. Fragment of the noise map of the city:
1-6 - city streets; Noise levels: i - 80 dB A; II - 76 dB A;
III - 65 dB A; IV - 79 dB A; V - 78 dB A; Vi - 70 dB a

The presented area mainly affect the transport highways (streets 1-2, 4-6) with high intensity of motion, especially freight transport. The territory, surrounded by these streets, is exposed to the noise of large intensity (78-80 dB a). Even at a distance of 100 m from the roadway, the noise intensity reaches 65 dB A.
Analysis of the noise card shows that the permanent growth of the car park in the presence of a large number of narrow streets and sidewalks, the lack of the necessary improvement and insulation of microdistrics and blocks from penetrating transport noise has created prerequisites for an increased noise background of the city. To ensure the acoustic comfort of the population, the width of the highway with such an intensive movement of transport must be at least 100-120 m.
The noise map makes it possible to identify the complex of factors affecting the acoustic regime, to recommend the rational placement of the functional zones of the city, which allows to weaken or completely eliminate the influence of the main sources of noise.
The most frequent causes of the level of noise are: insufficient territorial gap to ensure the noise protection of settlements, the territories of the mass recreation, resorts, therapeutic centers; violation of the regulatory documents or the lack of accounting for sanitary standards in the development and design of the main road and railway trails, airport locations; increasing the noise level from year to year due to the lack of new silent modes of transport, increase the capacity of jet engines of aircraft; High cost of sound protection structures, lack of technical and economic development in this area.
These causes are mainly determined by a promising set of noise protection measures.
The method of reducing noise on the path of its distribution is the greatest importance, including various activities: the organization of the necessary territorial gaps between sources of external noise and zones of various economic purposes with a normalized noise regime, rational planning and development of the territory, the use of terrain relief as natural natural screens, noise protection .
Special territorial gaps make it possible to significantly reduce the noise level in residential territories. Sanitary standards and rules provide for the creation of sanitary protection zones between production facilities, transport highways, airfields, marine and river ports and residential buildings. Within sanitary protection zones, the shielding buildings of non-residential purpose are allowed, in which noise level is allowed 55-60 dB and the noise properties of houses-screens are quite high. Especially effective extensive buildings like shopping rows. They reduce the transport noise by 20-30 dB A and reliably protect intra-quartered territory. The buildings of the screens can be placed garages, workshops, reception points of household service enterprises, dining rooms, cafes, restaurants, atelier, hairdressers, etc. You should not only be placed in this area of \u200b\u200bthe pharmacy, libraries and other institutions in which noise level should not exceed 40 dB A.
The optimal planning and development of the territory contributing to the reduction of noise levels provides for a rational trace of transit highways, laying them outside the towns and recreation places; The device of ring and semi-rival roads and bypass rail lines in suburban areas of cities with a population of more than 250 thousand people; localization of intensive sources of noise in the territory under consideration and separation of residential areas, mass recreation areas, tourism from industrial and factory zones and transport sources; The removal of the most powerful sources of noise beyond the territory under consideration or, on the contrary, deposancy of housing from the zone of increased noise.
The motorways I and II categories and railway lines, creating respectively equivalent noise level 85-87 and 80-83 dB A, should not cross the territory of the suburban zone, where forest parks, holiday homes, boarding houses, children's camps and medical institutions and sanatoriums, universities are placed Research institutes. Recreation homes need to be placed at a distance of at least 500 meters from roads and industrial enterprises and 1 km from the railway.
Industrial enterprises, areas or production areas that are noise sources of elevated levels (70-80 dB a), should be separated from residential buildings with protective zones and are placed taking into account the dominant direction of the wind. At the same time, other factors adhere to the environment are taken into account.
Industrial enterprises, equivalent noise levels of which are less than 60 dB A, can be located in industrial and residential areas if they are not sources of other negative effects.
Airports should be placed outside the city, outside the recreation areas. The distance from the borders of the runway of the airfield to the borders of the residential territory depends on the class of the airfield, intersection of the flight track with residential territory, and may vary in the range from 1 to 30 km.
To reduce noise in urban planning practice, natural shielding structures are used, based on the use of terrain - recesses, embankments, ravines, etc.
Exceptional ability to delay and absorb noise impacts have woody and shrubs planted along the motorways. The multi-row strip of wood-shrub planting with a height of 5-6 m is able to significantly reduce the noise level; The greatest effect is available broadbands - with a strip width of 25-30 m, a decrease in noise level is observed by 10-12 dB A. However, in the winter period, the protective function of green plantings is reduced by 3-4 times.
When developing projects for detailed planning and building buildings, the protective effect can be achieved by zoning the residential area. In the zone directly adjacent to the highway, it is necessary to have a low building of non-residential destination, in the next zone - low-rise living building, hereinafter - the living building of high floors and in the most distant zone - children's institutions, schools, polyclinics, hospitals, etc.
A significant reduction in noise level is achieved with a closed construction type (Table 43).
Efficiency of gas-noise development and relief elements
Table 43.

Type of construction	Reduced level
	pollution,%	noise DB A.
Solid nine-story perimeter construction	63	20-30
Perimetral nine-story building with arches	40	/>12-20
Perimetral nine-story building with ruptures	25	10-26
P-shaped nine-story building	50	18-22
Free nine-story building (80-120 m from the highway)	40	12-18
Location highway on mound	25	11
Location of the highway in the excavation	68	15

In the conditions of mass development of primary territories, multi-storey extended buildings for the protection of the population from transport noise are advisable to build special types of residential buildings. The bedrooms and most residential rooms must be oriented towards the yard, and the windows of common rooms without sleeping places, kitchens, flight-elevator nodes, veranda and galleries - towards the main streets. Not only the planning of apartments, but also noise-proof windows with triple glazing and a high degree of sealing, which will ensure special bounds will help the silence in the house. Massive walls and soundproofing plates are effective for eliminating noise from adjacent rooms.
In addition to urban planning activities, a complex of other events is used to eliminate noise pollution - installation on the equipment of soundproofing housings, emission silencers. In some countries, in particular, in Germany, there are noise protection zones in Germany, on many military and civil airfields that take reactive aircraft, the intensity of flights is limited until the prohibition of night flights, restrictions were introduced for supersonic aircraft over time, height, speed. For wheel-rail transport, technical methods of reduction of noise are applied: sound-absorbing wheeled blends, replacing boom brakes on disk et al. In some parts of the highways, a noise absorbing asphalt was used, having high porosity due to larger amount of emptiness (25% instead of 6% in conventional asphalt ). This made it possible to reduce the noise level on the roads of Germany by 4-6 dB.