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2017 |
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29
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Описание
С учетом всего вышеизложенного необходимо сделать следующие выводы:
- исследование и решение вопросов экологического страхования является очень важным и необходимым в современных условиях. Исходя из функций экологического страхования, можно сказать, что он может быть сильным фактором, влияющим на ситуацию в области контроля за негативным воздействием предприятий на окружающую среду, и тем самым снизить экологический риск и ущерб;
- развитие экологического страхования является сложным не только при отсутствии совершенной правовой базы, а также на тяжелое финансовое положение предприятий;
- насколько страхового института окружающей среды была создана сравнительно недавно, трудности в реализации системы экологического страхования связаны с отсутствием опыта и квалифицированных кадров;
- пробл ...
Содержание
1. Техносферная безопасности окружающей среды 2
2.Предвестники техногенных чрезвычайных ситуаций 5
3. Прогнозирование техногенных катастроф и роль космических систем в ее практической реализации 21
Выводы 29
Введение
Большое количество промышленных предприятий, являются как правило потенциально опасными объектами, как для человека и для окружающей среды. Они создают высокий риск возникновения чрезвычайных ситуаций и аварий, которые могут привести к необратимым экономическим и социальным последствиям. а такие причины, как административные методы управления и экономическое влияние механизма разрешения экологических деформаций с помощью быстрого природоохранных мероприятий за счет отсрочки перехода на новые технологические процессы кардинально улучшить экологическую ситуацию, а также неспособность предприятий осуществлять природоохранную деятельность способствовала деформации экологической ситуации в мире. Понимание этой ситуации и необходимость разработки новых ключевых моментов, требующих преобразования любого вида экономической деятельности в надежный, т. е. совместимый с требованиями гармоничного развития общества и природы.
Фрагмент работы для ознакомления
The period of time during which facilities are destroyed by such vibrations depends on the amplitude of alternating deformations as against their maximum levels. For example, corrosion increases cyclic stresses on the metal parts of pipelines tens and even hundreds of times.A rather commonly occurring phenomenon characterizing alternating cyclic stresses is the changing property of the rock mass in the areas of crustal fractures induced by such stresses. However, its external signs are not vivid and it is hard to determine their impact on technogenic objects. This phenomenon was for the first time described in the works of the Research and Technical Firm “Geofizprognoz” after studying crustal fracture zones using the profile shooting method. It was determined in particular that cyclic stresses in crustal fracture zones create areas with substantial deviations in strength and deformation properties of the rock mass. It was assumed that the rock mass in a crustal fracture zone is in thixotropic state. This helped solve numerous practical tasks such as determining the nature and patterns of a number of technogenic accidents and disasters (including an accident in St. Petersburg’s subway system).Thixotropy is known to occur in a number of soils and rocks during earthquakes. Alternating cyclic stresses cause them (while having considerable bearing power in static condition) to soften and lose a great deal of their strength, which often results in the tilting and collapse of dwelling houses and other engineering systems. However, this phenomenon occurs only briefly during an earthquake and soil regains its strength after the end of the tremors. Thixotropy in crustal fracture zones, which in many cases consist of rock with a more deformed structure, occurs implicitly for long periods of time and possibly even continuously in historical terms. This phenomenon can be described more precisely by the term “quasi thixotropy.” It is believed that the quasi-thixotropic condition of rock in a crustal fracture zone is caused by alternating cyclic displacements, when induced stresses change their strength and deformation properties. Depending on the design features of installations that interact with the rock in a crustal fracture zone, different patterns and scenarios of emergencies can evolve.For example, the north-western wall of the main open-cut mine at the Korshunovsky ore dressing factory (Urals) has been in critical condition for more than 35 years in a section crossed by a 500-meter latitudinal fracture. Big landslides with the slope angle of 22 have been occurring in the mine since 1975, even though its underlying sedimentary rocks were estimated to remain stable at bigger angles of 28-30. The movement of surveying posts placed along the perimeter of the mine has been monitored annually to expose their cyclic displacement. The transforma¬tion of the rock mass is considered to be a transition to thixotropic state. For example, the mine has a water gallery that draws off the local river from the production area. An examination of the gallery showed that the monolithic reinforced concrete lining in the crustal fracture zone is divided by ring fractures into 7-10-meter sections through which underground water seeps into the gallery, sometimes even spurting under pressure. However, the fractures have practically never occurred in the construction joints in the lining. Therefore, an emergency at the Korshunovsky open-cut mine is developing mainly due to active geodynamic processes in the crustal fracture zone, which requires constant monitoring in order to prevent irreversible destruction.Intensified karstification is one of the factors that provoke technogenic emergencies. Russian scientists encountered this phenomenon when studying the causes of increased karstification in the residential area of the city of Kamensk- Uralsk and in one of the sections of the Bukhara-Urals gas pipeline near the city of Yemanzhelinsk. Dolines appeared to have been caused by alternating stresses in the rocks and their transition into quasi-thixotropic state that had intensified erosion. A series of sinkholes in the crustal fracture zone that crosses the gas pipeline route had resulted in the exposure of its third section, creating a serious technogenic danger.Geodynamic phenomena in the earth’s crust occur naturally due to tectonic processes, or are caused by anthropogenic activities. The geodynamic crustal patterns that manifest themselves through crustal deformations are the same. The difference is in scale and physics. For example, some studies indicate that the area of geodynamic processes caused by the operation of a big mining enterprise can have a radius of several dozen kilometers.Slow deformations, as a rule, are not accompanied by seismic effects, and devastating consequences are limited either to the foundation of a facility or the facility itself if it is of an underground (semi-buried) type. However, despite the absence of seismic effects, the danger of such deformations is characterized by relatively high rates of changes in the earth’s crust that can reach 3H0~3 m a year even in seismically quiet regions of the Urals. This happened in 1961-1962 in two districts of Sverdlovsk region where 0.4-km-wide-open fissures had developed.The observable spread of areas of slow deformations and crustal movements poses a real threat to vital and environmentally vulnerable technical facilities. Such zones occurring in places of crustal fractures are likely to cross extended technical facilities such as trunk pipelines, railroads, power transmission lines, etc., as well as protective dams on water reservoirs, and mining sites.Theoretical studies of large-scale technogenic effects on a given section of the lithosphere are based on classical solutions of flow mechanics. Experimental studies of deformation caused by man-made effects of mining operations are conducted by way of monitoring survey markers installed at the mining sites. Given the size of such sites, such monitoring became effectively possible only after the use of GPS geodetic devices for research purposes.It is common knowledge that the Urals is the biggest and the oldest mining region in Russia and the risk of technogenic accidents caused by intensive mining operations is quite real there. For example, the three biggest open-cut mines in the Urals which produce iron ore (Kachkanar), asbestos (Asbest), and coal (Korkino) have already exceeded the permissible level of technogenic impact beyond which induced geodynamic processes begin. A similar situation can be seen in the areas of underground production of salt (Solimkamsk), bauxites (Severouralsk and Satka), and iron ore (Kushva, Nizhny Tagil). Specialists name at least seven mining areas that are potentially dangerous in terms of induced geodynamic processes. Such processes, including earthquakes with a magnitude of M = 4-6, have already occurred in some of them.The Mining Institute of the Urals Branch of the Russian Academy of Sciences has extensive instrumental monitoring data concerning the movement of rocks at the mining enterprises in the Urals over more than 30 years. Satellite surveying technologies open up utterly new opportunities in this field. The institute has created the Urals Center for Geomechanical Studies of the Nature of Technogenic Accidents in the Mining Areas, which has GPS surveying equipment that can monitor crustal deformations caused by the technogenic impact of mining operations. The Center’s laboratory studies of plate models and analytical calculations based on the theory of shells indicate that natural horizontal tectonic stresses in the crust (the first invariant of which is estimated at 30.8 MPa on average [9]) create a certain critical load that can cause a deformation. This form of buckling distin¬guished in the theory of shells causes immediate deformations and seismic effects. Technogenic loads in this case act as a trigger that determines the time and the place of such occurrences.So, stresses and deformations in large sections of the earth’s crust change considerably due to long-term mining operations, which can cause geodynamic processes and disastrous consequences. Therefore, the study of deformation patterns in the upper layers of the lithosphere caused by long-term mining operations becomes particularly relevant. The forecasting of technogenic disasters, their dynamics and prevention requires geodetic monitoring using satellite surveying and aerospace surveillance technologies.The interconnection between contemporary geodynamic processes and the yet- to-be-discovered mechanisms of technogenic disasters in the mining industry provides a theoretical basis for determining a strategy for fundamental studies related to forecasting anthropogenic emergencies. In the future, this can help solve more effectively a number of applied tasks aimed at preventing such emergencies and reducing their negative effects. Scientific results achieved in the field of seismic location and spectral seismic surveying can be of interest in this respect. It is known that so-called “areas of tectonic faulting” in the lithosphere are often blamed for different technogenic disasters, such as sudden collapses of buildings and installations, road cave-ins, pipeline bursts, rail ruptures, etc. By detecting these zones, it is possible to forecast technogenic accidents and disasters (this is what geological engineering was created for).Studying and mapping areas of tectonic faulting have become possible with the development of the spectral seismic survey profiling method, which can detect such areas through increased values of the Q-factor in the harmonic components of the seismic signal. It is known that the notion of the Q-factor can be applied only to decaying harmonic signals. A signal can be either harmonic or generated by interference of nonharmonic components. If it does not contain a decaying harmonic process, i.e., it was generated by interference, its Q-factor equals 1. The slower a decaying harmonic signal fades out, the bigger its Q-factor is. Conversely, the longer (slower) a harmonic signal fades out, the more destructive its consequences are. The Q-factor describes both the decaying harmonic signal and the vibrating system that generated it (if there is a signal with a Q-factor, the vibrating system that generated it has the same factor).It is known that resonance is a coincidence of the frequency of periodic external impact with the frequency of the vibrating system that is experiencing such impact. Such interaction generates a gradual, from period to period, increase in the amplitude of vibrations. The amplitude can increase Q times. Real values of the Q-factor in areas of tectonic faulting range between 50 and 100, but the growth of vibration amplitude is restricted by elastic deformation limits and the ensuing accident. Usually, destruction takes place before the maximum amplitude has been reached, and it occurs instantaneously as if struck. This phenomenon is well known and is called a mine shock or a technogenic earthquake.The safety of many engineering systems is assessed in terms of resistance to resonances. Bridges are known to have collapsed under marching troops due to resonance when the frequency of the rhythmically stepping people coincided with the own frequency of the bridge’s elements as vibrating systems with a high Q factor. However, the possibility of resonance in the “engineering system - earth strata as a foothold” has never been considered. Many technogenic disasters have never got explanation due to this reason. For example, accidents at facilities that have vibrational impact on soil (different power plants, pumping stations, etc.). Entering into resonance is a transitional process that can be caused by a change in the work of a vibrating object, such as a change in the frequency of vibration due to a higher or lower generator speed (as was the case at the Chernobyl nuclear power plant) or the passage of a train at a certain speed through an area of tectonic faulting. This category of technogenic accidents can be effectively forecasted using the spectral seismic profiling method based on seismic location. So, with time, after resonance phenomena have been better studied, it will be possible to avoid technogenic accidents similar to those described above.But another cause of destruction - planetary pulsation - is much more trouble-some for engineering systems. Some of its manifestations are known. For example, it causes significant surveying errors in certain places. Planetary pulsation occurs exclusively in areas of tectonic faulting and has a rather small frequency (tenths and hundredth of a Hertz). The amplitude of such vibrations can reach 10 cm, but it is not constant and can dwindle to zero from time to time. The vector of an alternating shift in the pulsing surface changes with time both in value and direction. The frequency of pulsation changes as well.Planetary pulsation by itself causes engineering systems to collapse. This can be easily understood if one imagines that one part of the foundation under an installation stands on stable soil, while the other part, being located in an area of tectonic faulting, starts swaying. Naturally, neither a reinforced concrete nor even metal (pipelines, railway tracks, etc.) construction can withstand such loads, even though the latter can, unlike the former, absorb bending stresses. The generally accepted point of view is that the stronger the foundation, the safer the engineering system is. However, practical experience indicates that the strengthening of the foundation does not always increase safety, especially if the foundation is designed without taking into account planetary pulsation (it’s like a young flexible tree that can survive a storm that can break an old and unbending one). A break in reinforced concrete plates in the so-called “floating base” caused the collapse of the water park in Moscow’s Yasenevo district, killing and injuring dozens of people.The impact of planetary pulsation on certain vertical constructions (posts, supports, etc.) causes them to incline toward the center of the stress zone (this explains why posts and trees tilt in the same direction). As a rule, the objects that tilt are located on the fringe of the zone, while those in its center sway. Clearly, if vertical posts holding a pyramidal roof sway, the risk of its collapse increases. Pulsation causes piles driven into the ground to sway in much the same way. If they are built into the foundation frame or floating base, either a pile itself will break at the place of attachment or the construction to which it is affixed will fall apart. When planetary pulsation increases, the number of such incidents increases too. This happened in the winter of 2005-2006 when the roofs of several reinforced concrete buildings in Russia, the Czech Republic, Switzerland, and Germany collapsed at the same time.The sudden collapse of pumping stations standing on piles built into a floating base occurs quite frequently in the Russian oil and gas industry. After studying the construction of the piled foundation at one of the enterprises in Surgut, experts came to a paradoxical conclusion: the use of the most up-to-date technologies and materials does not make a building stronger and may even increase the risk of its subsequent collapse if vibratory properties of the lithosphere are not taken into account.An observation of piling operations showed that it takes dozens of times fewer strikes to drive some of the piles into the ground, suggesting lesser friction between a pile and the soil, which usually happens in tectonic stress zones due to the highly loose rock mass that makes up the upper layer of the lithosphere. What makes these measurements distinct is that six piles driven into the ground and standing next to each other were examined twice: the first time, when the pile was struck and the second time when the soil around it was struck (in both cases, a seismic receiver was affixed to a pile).A common feature shown by all piles was that their length on the ultrasonic image was not very clear with the exception of pile No. 2, the size of which upon impact appeared to be much clearer than that of the other piles, but it did not register at all when the ground around it was struck. This can be explained by lesser friction between pile No. 2 and the soil when, on the one hand, its own lengthwise vibrations are not dampened, and, on the other hand, there is a reduced acoustic contact with the ground. There was yet another interesting effect: when the ground was struck, the above-mentioned harmonic vibration process with a colossal Q factor was registered at a certain frequency f0.Although it is not quite clear what exactly generated this vibration process in the “pile-soil” system, such a vibrating system with a high Q factor is the reason for the resonance with the vibration object, for which the foundation was essentially built, and the cause of a mine shock. This leads to explosion-like and instantaneous destruction of the foundation as in the case of gas pumping stations.Sometimes, it takes a very small number of strikes to drive a pile into the ground. It is also believed that it can’t hurt if a certain number of piles simply hang upon the plate rather than hold it. However, such hanging piles will sway to break loose of the plate, and if there are many of them, the plate can simply snap. So, if a facility with vibrating devices is built in an area of tectonic stress, there are two factors causing the plate to snap: vibration and planetary pulsation. If a facility happens to be in a hazardous zone, a piled foundation with a floating base runs a greater risk of sudden collapse than when a floating base and piles are not used at all.Therefore, there are two types of alternating impact on the lithosphere: vibration from working mechanisms and planetary pulsation. The former, being a higher frequency one, can cause resonance with the own frequencies of adjacent rocks, while the latter, as a low frequency one, can cause resonance with the underlying structures (for example, the pulsation frequency of 1 Hz corresponds to a 2.5-kilometer stratum, and a frequency of 0.1 Hz corresponds to a 25-kilometer stratum). If the frequency of planetary pulsation is close to the own frequency of the lithosphere structure, and if its Q factor as a vibrating system is big enough, the risk of resonance phenomena, i.e., earthquakes, increases immensely.The pattern of a natural earthquake differs from that of a technogenic one. It happens even if the frequency of planetary pulsation changes and nears the frequency of resonance. The amplitude of soil vibrations increases, as has been registered by seismologists immediately before an earthquake. If the frequency of planetary pulsation does not coincide with the own frequency of the relevant vibrating system but is close to it, so-called beats occur.The earth’s crust in areas of tectonic faulting appears to be quite mobile and using it without taking this factor into account increases the frequency of technogenic accidents, and the oftener the ground comes under static or dynamic impact, the more intensive they will be. A transition to the perception of earth strata as a combination of vibrating systems both in the general methodological and purely practical terms is as important as is the transition from geocentric to heliocentric views, and helps to make the operation of engineering and technical systems safer. Such a change of paradigm will make it possible to reduce consider-ably the number of technogenic accidents, rule out technogenic seismic processes and effectively forecast natural earthquakes.3.
Список литературы
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