The Alexander Column as a compositional center of the architectural ensemble of Palace Square in Saint Petersburg, Russia, has always been a matter of concern for both the public and specialists due to progressive deterioration of its granite shaft caused by crack formation. The article examines previous studies related to the inspection and restoration of the column's shaft and other parts above ground level, as well as reasons for crack initiation and propagation in the column. An analysis was performed on the anomalies in the Fennoscandian Shield and the structural-tectonic conditions at the Montferrand quarry site, revealing the presence of faults and circular features within the studied area. The research considers N.Hast's measurements of excess tectonic stresses in anomaly zones (southeastern Finland), which acted horizontally and resulted in the development of tensile cracks within the granite massif and later in the column’s shaft after its installation. The most dangerous type of deformation for the Alexander Column is its tilt in the northeast direction, recorded in 1937 and 2000. The article analyzes the construction features of the column's foundations and additional underground elements, as well as soil and groundwater characteristics based on archival data. The contamination history of the underground space is taken into account, and an analogy-based method is used to assess the engineering-geological and hydrogeological conditions of the underground load-bearing structures within the placement zone of the Alexander Column and the New Hermitage buildings. The results of visual observations on the nature of deterioration and deformation of the pavement around the monument, as well as its pedestal, indicating the development of uneven settlement of the foundation, are presented. The article concludes with general recommendations for organizing and implementing comprehensive monitoring to forecast the deformation dynamics of the Alexander Column.
The article reviews the issues concerned with correctness of the engineering-geological and hydrogeological assessment of the Upper Kotlin clays, which serve as the foundation or host medium for facilities of various applications. It is claimed that the Upper Kotlin clays should be regarded as a fissured-block medium and, consequently, their assessment as an absolutely impermeablestratum should be totally excluded. Presence of a high-pressure Vendian aquifer in the lower part of the geological profile of the Vendian sediments causes inflow of these saline waters through the fissured clay strata, which promotes upheaval of tunnels as well as corrosion of their lining. The nature of the corrosion processes is defined not only by the chemical composition and physical and chemical features of these waters, but also by the biochemical factor, i.e. the availability of a rich microbial community. For the first time ever, the effect of saline water inflow into the Vendian complex on negative transformation of the clay blocks was studied. Experimental results revealed a decrease in the clay shear resistance caused by transformation of the structural bonds and microbial activity with the clay’s physical state being unchanged. Typification of the Upper Kotlin clay section has been performed for the region of Saint Petersburg in terms of the complexity of surface and underground building conditions. Fissuring of the bedclays, the possibility of confined groundwater inflow through the fissured strata and the consequent reduction of the block strength as well as the active corrosion of underground load-bearing structures must be taken into account in designing unique and typical surface and underground facilities and have to be incorporated into the normative documents.
The underground space of the Kupol deposit is analyzed as a multicomponent system – rocks, underground water, microbiota, gases (including the mine atmosphere) and supporting structures – metal support and shotcrete (as an additional type of barring) and also stowing materials. The complex of host rocks is highly disintegrated due to active tectonic and volcanic activity in the Cretaceous period. The thickness of sub-permafrost reaches 250-300 m. In 2014, they were found to contain cryopegs with abnormal mineralization and pH, which led to the destruction of metal supports and the caving formation. The underground waters of the sub-permafrost aquifer are chemically chloride-sulfate sodium-calcium with a mineralization of 3-5 g/dm 3 . According to microbiological analysis, they contain anaerobic and aerobic forms of microorganisms, including micromycetes, bacteria and actinomycetes. The activity of microorganisms is accompanied by the generation of hydrogen sulfide and carbon dioxide. The main types of corrosion – chemical (sulfate and carbon dioxide), electrochemical and biocorrosion are considered. The most hazardous is the biocorrosion associated with the active functioning of the microbiota. Forecasting and systematization of mining and geological processes are carried out taking into account the presence of two zones in depth – sub-permafrost and below the bottom of the sub-permafrost, where mining operations are currently underdone. The importance of assessing the underground space as a multicomponent environment in predicting mining and geological processes is shown, which can serve as the basis for creating and developing specialized monitoring complex in difficult engineering and geological conditions of the deposit under consideration.
The article presents the features of transformation and migration of petroleum products in the underground environment, which are determined by the physical and physicochemical properties of petroleum hydrocarbons (density, viscosity, solubility in water, etc.) and their enclosing soils (sorption capacity, humidity, etc.). The main processes of degradation of oil products in the soil stratum are considered. The influence of oil products on the change in oxidation-reduction and acid-alkaline conditions of the underground space, development of activity of various forms of microorganisms is shown. The change in the composition and properties of dispersive soils of various degrees of water saturation is experimentally studied. The analysis of the causes of the reservoir destruction used for storage of fuel oil is given. It was established that the development of microbial activity at its base led to the transition of sands to quicksands, and moraine loams to quasi-plastic varieties. Intensive gas formation of methane and its homologues, nitrogen, carbon dioxide, hydrogen in sands was recorded. Based on the analysis of the results of long-term monitoring of the effect of contamination of dispersive soils by oil products, their bearing capacity in the base of the structures has been reduced to 50% of the initial value. The role of microbial activity in the formation of an aggressive environment in relation to building materials is shown.
The paper deals with the main petroleum hydrocarbon sources in the earth cover. Oil products influence on intensification of different microbial forms activity as well as on bio-chemical transformation of the pollutants themselves is shown. Changes in state and properties of soils due to microbial degradation of oil products are experimentally studied. The analysis of reservoir destruction through the example of black oil fuel storage is carried out. Results of determining different groups of microorganisms in soils and groundwater in the fuel oil storage tank area cross-section are given. The role of microbial activity in bearing capacity change of sandy-argillaceous soils with specific reference is presented.
Drainage water formation of the Yakovlevsky mine (Yakovlevsky deposit, KMA) is considered, as well as the features of its discharge to soak away and thereto related ecological issues. Ways of drainage water treatment are presented. The particular focus is given to the project of its disposal in the high-head Lower Carboniferous aquifer using injection methods. Negative effects of this measure and nature of its impact on the water-protective layer, determining safety of mining operations, are stated.
The analysis of engineering and geological conditions of Primorskiy district of Saint Petersburg associated with the prospects of its areas development up to the year 2025. Its structural and tectonic conditions are represented. Results of microbiological analysis of soils from the section of Juntolovskiy reserve are given. The research of microbial flora of Lakchtinskoye swamp peats are carried out. The analysis of basic engineering and geological problems related with microbial activity is given. The main natural and technogenic sources of underground water and soils contamination are considered, and also some measures that provide longterm com-petence of constructions of different appointment are recommended.
The analysis the characteristics and specificity the formation of Predglintovoy lowlands is carried out. The regularities of changes in the state and the strength of blue clay at the depth of cut, taking into account their degree of disintegration – layering and fracturing. The influence of macro- and microcracks in the blue clay zone predglintovoy on their strength and deformation ability is investigated. Basic provisions of engineering-geological analysis of the territory are developed. Recommendations to improve the safety and reliability estimates of blue clay as base of constructions of different function are offered.
The short characteristic of engineering-geological and hydrological conditions of the grounds of concrete constructions is given. Factors of formation of ecological conditions in a benthonic zone of a water basin of Cheboksary hydroelectric power plant are analyzed. Dynamics of change of activity and number of microorganisms in water and bed deposits of a water basin is considered. Results of specialized shooting in dry footway about a condition of concrete of a hydroelectric power plant building of and an overflow dam in 2010-2011 are stated, the comparative estimation of microbiological activity which promotes development of the vigorous activity of biocorrosion of concrete and metals is spent. It is shown high microbes prevalence the materials applied to repair work (seals of various defects in concrete designs).
The effect of physical-chemical and chemical factors on peculiarities of swell and osmotic shrinkage of clay provided to unmembrane’s effect is analyzed. It is demonstrate that the genesis of swell due to water inflow in soil and its outflow is principally different and depends on different correlation of clay pore water concentration (Сп) and solutions filter-passing (Сф). The balance equations for five types of swells are adduced. The experimental researches are allowed to obtain the equation for calculation of solution concentration (boundary of osmotic shrinkage Споу). The exceeding of Споу leads to osmotic shrinkage of clay formation. The conclusion of strength and deformation capacity of clay by swell and shrinkage is gained.
Features of engineering-geological and hydrological conditions of the basis of concrete constructions are analyzed. Factors of formation of ecological conditions in a bottom zone of a water basin of Cheboksary hydroelectric power plant are analyzed. The maintenance and change of activity and number of microorganisms in water and ground adjournment of a water basin is considered. Results of specialized shooting in dry gallery about a condition of concrete of a building of hydroelectric power plant and an spillway dike in 2010-2011 are stated, the comparative estimation of microbiological activity which promotes development of active biocorrosion of concrete and metals is spent.
The estimation of main factors which exerts influence upon functioning reliability of system «tunnels – underground space» is executed. It is shown that hydrogeological conditions have a special importance for construction and maintenance of subway tunnels in Saint-Petersburg. The hydrodynamic effect of regional and local water-bearing horizons on development and activation of different processes such as groundwaters flow, quicksands, head water inrush, underground constructions deformation is analyzed. The influence of hydrochemical conditions on formation of underground space aggressiveness to constructional and waterproofing materials of the tunnels is established. The negative effect of underground microbiota activity on degradation of reinforced concrete and castiron tunnel lining is shown.
Complexity of hydrogeological and engineering-geological conditions of the Jakovlevsky deposit and the basic tendencies of their change is characterized at expansion of front of mining works and increases in volumes of extraction of rich iron ores. It is noticed that safety of conducting mining works is defined by formation and development of dangerous mining-and- geological processes. Substantive provisions of forecasting of mining-and-geological processes on Jakovlevsky mine are resulted. Possibility of occurrence of underground waters breaks from undrained water bearing horizons is considered. Ordering of processes of native and native-technogenetics genesis within an allotment of Jakovlevsky mine is executed and the basic directions of actions for increase of safety of exploitation of mine are planned.
The study presents influence biotic and abiotic components in underground space on formation and changes of sandy soils conditions and properties under peat, contamination of leaking sewages and some industrial enterprises. The regularities of decreasing of density, water permeability and shear strength of sand due to good disintegrated peat by experimental are analyzed. The organic component of biotic genesis leading to extremely negative effect on permeability and mechanical properties of water saturated sands till to quicksands is shown. The local constructional norms for Saint-Petersburg on the base of getting results should be modernized.
In the paper construction specificity of St. Isaak Cathedral’s underground space and engineering geological profile features are considered. The comparative assessment of condition and properties modification of water-saturated quarternary sandy and clay soils during 55 years are taken up (1954-2009). The dynamic of groundwater contamination due to leakage sewers and its aggressiveness are estimated. The researches of microbes activity in soils which are characterized by quasiheavy values are completed. The structural of complex monitoring to secure of St. Isaak Cathedral long-term stability are proposed.
Development’s conditions and sources of microorganisms in high-grade iron ore (HGIO) of Jakovlevsky deposit (KMA) were considered. Influence of watering, draining and contamina tion in iron ore on decreasing of shear strength and growth of bacterial mass were noticed. Dif ferent physiological groups and species composition of microorganisms in underground space were defined, and their influences on constructional materials which are used to coffer mine workings were studied.
In article researched difficult hydro-geological conditions of the Jakovlevsky deposit rich iron ores on which mining going under not-drained high-pressured bottomcoal water-bearing horizon. The purpose spent monitoring is resulted. The comparative analysis of results of three cycles of a hydro-geological monitoring which has shown gradual expansion of front of an over flowing of underground waters from not-drained horizon is made. Negative consequences of such process are specified. The development features of various biological forms of a life in mine which destroy construction materials are noted. Actions for decrease in consequences of an overflowing are planned.
Reasons of transition tunnel construction to the pre-emergency state and the nature of landslide displacements trimmed slope, which can be traced in the context of the Lower Cambrian blue clay are defined. Influence of microbial activity as a negative factor fracture of structural materials, as well as strength reducing of blue clay. Regularities of changes in the state and the strength of blue clay at the depth, taking into account their degree of disintegration – layering and fracturing. The quantitative evaluation of stability of the construction of the transport tunnel, taking into account changes in the strength of blue clay as an fissered medium at different positions of the landslide surface. The strategy of measures to ensure the reliability of the facilities.
Briquetting in ferrous metallurgy is the earliest way clotting. In the beginning of XX century briquetting has been forced out by agglomeration basically for the reason considerably more productivity of process of agglomeration. As alternative to agglomeration pelletizing became. It started to be popular in the XX-th century, that is quite explainable by essential increase of manu- facture fine particle concentrates. However briquetting has a number of advantages. For some kinds of iron ores briquetting can be preferable process. Such ores are rich iron ores with iron content 60 % and more. The technology of briquetting includes crushing, preliminary screening for removing of large particle size classes; dispensing and mixing martite ore, and hydrohematite ores; mixing with binder substances; pressing; screening for removing of small size briquettes; drying. The received briquettes have density 3200-3600 kg/m3, durability on uniaxial compression more then 4,5 MPа.
Rich iron ores of the Jakovlevsky deposit are fine metallurgical raw materials. These ores are suitable for melt of high-quality metal at the minimum cost price as doesn't demand mineral processing. Ores contain a considerable quantity of fine classes particles and need briquetting. Mining operations include quality control of mined ore. The technology of briquetting includes, preliminary screening for removing of large classes; dispensing and preliminary mixing 85-90 % martite, iron-micaceousmartite ores and 10-15 % hydrohematite ores; mixing with connective substances; pressing; drying. The received briquettes have density 3200-3500 kg/m 3 , durability on compression 4,5 MPа.
Engineering-geological and hydro-geological features of rent of St. Petersburg are considered. It is noted that at designing buildings for different purposes, in order to ensure their long-term stability it is necessary to analyze the possibility of their transformation the main components of underground space (rocks, underground water, gas, microbiota, underground structures) under the influence of natural and technogenic factors. Examples of transformation of sand-clay soils under the influence of physical and chemical conditions change and activization of microbial activity in underground space are given. The case of transition of a heavy construction to a pre-emergency condition because of mistakes in engineering research and incorrect assigning of computative parameters is analyzed.
The natural and technogenic factors effect on exploitation reliability of subway tunnels located in Upper Vendian clays are analyzed. It is noted what the fractured clays has been studied during the exploring of the first metropolitan lines. It is emphasized what the intensity of clay fracturing increases in thalweg zones of paleo-valleys within the bounds of which the quantity of underground water leakages in tunnels increases. The hydrodynamic and hydrochemistry conditions of Vendian high head horizon (lied under clays) influence on deformation and destruction of tunnels lining are investigated. The reduction of clays shear strength parameters under the interaction of clays and liquid phases is experimentally studied. The water extracts chemical composition of disintegrated construction materials and sinter forms are resulted. The important role of biocorroion in constructional and waterproof materials (included bitumen) disintegration is shown. The protection methods of tunnels constructions from biocorrosion are recommended.
Specificity of hydro-geological conditions of the Jakovlevsky deposit and operating system of a drainage on the mine with the same name is resulted. It is underlined that mine works are conducted under not drained high pressure water-bearing horizons. The complex hydrochemical and hydrodynamic monitoring of underground waters is considered as implement for increase of safety of extraction mine works in difficult mine-geological conditions. The comparative analysis of hydro-geological monitoring three cycle’s results which has shown gradual expansion of underground waters overflowing front from not drained horizon is carried out. Negative consequences of such process are specified. The development features of various biological forms of a life in mine which destroy construction materials are noted. Actions for decrease in consequences of an overflowing are planned.
The history of high-rise construction is considered summarily. The main features of high-rise buildings and difficulties connected with theirs engineering and construction especially with underground space development and deep excavations in soft water saturated soils are characterized. Territorial construction guides «Residential and social high-rise buildings» prevail in Saint-Petersburg are analyzed in the context of recommendations for reliable basement choice. Brief description of Pre-Quanernary clays (Upper Vendian clays and Lower Cambrian clays) as basement for high-rise constructions are given. It is placed emphasis that the main feature of Pre-Quaternary clays is zone sequence of physical and mechanical properties and fissuring in depth. Physical and mechanical properties of Upper Vendian clays, Lower Cambrian clays and glacial clays are given. In addition, it is confirmed that glacial soils is not recommended to use as a basement for high-rise buildings.
The article deals with geomechanical and hydrogeological problems under the Yakovlevsky ore deposit development including variations in strength properties. The estimation of feasible underground water inrush inside the mining excavation is done. In situ results of ore strata deformation around excavation are discussed. Numerical modeling of stress and strain in the waterproofing ore pillar due to partially backfilling of excavation is carried out.
It is noticed that the chosen territory for nuclear-waste disposal in Lower Cambrian clay massif nearby Koporje of Leningrad region takes place in a tectonic zone. Lower Cambrian clays are considered as the block-fractured rock mass having a depth zone structure. The long radioactive irradiation of dark blue clays has led to transformation of their structure, physical-chemical and physical-mechanical properties, and also to activization of microbial activity. Nine criteria to the geoenvironmental and engineering geological characteristics allowing in a complex to estimate safety and reliability of a nuclear-waste disposal in clay formations on an example of dark blue clays are suggested.
The basic principles of organization and carrying out of hydrogeochemical monitoring according to the set parameters of chemical compounds of mine water at Yakovlevsky mine are given. Monitoring allows to estimate the activity of overflow and secondary moistening of rich iron ores in the mine. At carrying out of monitoring the general occurrence of hydrogen sulfide (H2S) of various genesis is revealed. The correlation of H2S and chlor- ionic maintenance was obtained. Zones of active water overflow from low-carbon limestone at horizons -425 m and -370 m were outlined. The possibility of corrosion of concrete and metals under the influence of H2S is shown.
The main natural and anthropogenic factors determining the nature and mechanics of fractures of deep underground tunnel structures lining are considered. On the basis of the conducted research in underground excavations the systematization of the main forms of destruction is carried out. The composition of water extracts prepared from the destroyed concrete and various forms of neoplasms was investigated. Determination of the number and types of microorganisms - micro-mycetes, bacteria and actinomycetes - was carried out. Based on the results of experimental studies, a conclusion is made about the role of biocorrosion in the destruction of tubing and waterproofing jacket. Particular attention is paid to the impact of pressure water of the Lower Kotlin aquifer, which creates favorable conditions for the development of microbiota and its aggressive effect on structural materials.
The problem of surface subsidence under intensive downward influence of artesian waters is considered. Changes in the Lower Kotlin aquifer affecting surface and underground structures in St. Petersburg are characterized. Examples of destruction of structural materials during the construction of transportation tunnels are shown. Recommendations on prevention of corrosiveness of structural materials are given.
The main natural and anthropogenic factors determining the vitality of diverse microbiota in the underground space (US) of St. Petersburg are analyzed. The data on characteristic microbial flora of buried bogs, contributing to the growth of microorganisms in the underlying soils are given. The processes influencing the formation of reductive-oxidizing and acid-alkaline conditions and viability of various physiological groups of microorganisms in RS are considered. Peculiarities of destruction of foundation brickwork, reinforced concrete and cast-iron lining of some transportation tunnels are considered. A comparative assessment of the influence of water extracts selected from fractured building materials and new formations on the chemical composition of tunnel linings is given. The metabolism of various bacteria and microfungi leading to the destruction of building materials is characterized.
На первоочередном участке ведения горных работ Яковлевского рудника выполнено гидрогеомеханическое зонирование, позволившее выделить три зоны разной проницаемости пород толщи, которая отделяет высоконапорный нижнекаменноугольный горизонт от рудно-кристаллического горизонта. Предложены основные подходы к организации гидрогеомеханического мониторинга непосредственно в подземных горных выработках рудника, включающего мониторинг подземных вод и геомеханический мониторинг. Даны методические рекомендации к постановке основных работ, входящих в систему гидрогеомеханического мониторинга.
Рассмотрена природа формирования физико-механических свойств богатых железных руд (БЖР) как продукта химического выветривания железистых кварцитов. Проанализировано влияние остаточных и вторичных цементационных связей на прочности и устойчивость БЖР. Приведены данные оценки физических свойств осушенных и водонасыщенных БЖР. Показано, что разуплотнение БЖР приводит к существенному повышению их пористости до 50 % и более. Рассмотрены особенности деформационного поведения и прочности руд по результатам экспериментальных исследований, проведенных на образцах ненарушенного сложения. Диапазон показателей сопротивления сдвигу БЖР позволяет проводить расчеты устойчивости при различных условиях их водонасыщения и осушения.
Рассмотрены общие положения возможности формирования прорывов вод при ведении горных работ под водными объектами, в том числе неосушенными водоносными горизонтами. Приведен пример аварийных ситуаций при проходке подземных выработок ниже уровня моря. Выполнены расчеты допускаемых напоров с использованием реальных характеристик прочности БЖР и проектных пролетов одиночных выработок. Показано, что только в условиях полного осушения руд можно гарантировать устойчивость потолочины при ведении горных работ на горизонте –370 м. Рассчитано возможное время перетекания вод из нижнекаменноугольного водоносного горизонта в рудную толщу. Предложена организация специального мониторинга перетекания подземных вод по гидрохимическим показателям .
Рассмотрены основные факторы, определяющие развитие микробной деятельности в рудном теле богатых железистых руд Яковлевского месторождения КМА. Исследовано влияние увлажнения, загрязнения и дренажа на рост бактериальной массы в богатых железных рудах. Показана взаимосвязь между прочностью руд и величиной бактериальной массы. Экспериментально определены некоторые физиологические группы и виды микроорганизмов, в том числе микромицеты, а также их численность. Проанализирована активность воздействия биоценозов в условиях Яковлевского рудника на конструкционные материалы – металлы и бетоны.
The main leading factors (changes in the stress state of rocks at the base of structures, physico-chemical and biochemical conditions) determining the long-term stability of surface structures are analyzed. It is noted that filtration consolidation is not of practical importance when considering the compressibility of rocks. The influence of physico-chemical factors on sandy-clayey rocks is evident when polluted by runoff with a wide range of mineralization and composition. The effect of intensification of microbial activity, during which biochemical gases are formed and the increase in the content of bacterial mass, on reducing the strength and deformation capacity of clayey rocks is particularly emphasized. It was found that the transformed clay rocks are usually characterized by the presence of quasi-plastic state.
The features of the structure of the St. Petersburg bedrock clay massif as a fractured-block environment are considered. The genesis of fracture formation due to tectonic and non-tectonic factors is analyzed, the zoning structure of the clay strata along the depth of the section, which is determined by the block size and the range of humidity and density changes. The regularities of changes in the parameters of shear resistance and general deformation modulus of clays by depth, as well as the influence of the scale effect on the same parameters of mechanical properties, are presented.
The composition, structure, physical, physical-chemical, and mechanical properties of blue Lower Cambrian clays in the western part of the Leningrad Oblast have been analyzed. The blue clay formation is considered as a medium for the disposal of radioactive waste near the Koporje settlement. Complex analysis and assessment of the conditions of formation and transformation of blue clays under the influence of natural and anthropogenic factors has shown that prolonged radioactive irradiation of clay strata leads to an increase in the disintegration of clays, reduces the resistance to shear and deformation properties indicators of the activation of microbiological activity, which are considered as a negative factor. Changes in clay properties contribute to the disturbance of hydrodynamic conditions and increase the risk of aquifer pollution. Nine criteria for safe operation of underground storage facilities based on the study of engineering-geological and geo-environmental factors are proposed. Long-term safety of operation of underground storage facilities in clay strata should be based on the multi-barrier concept of environmental protection.
Analysis of the scientific legacy of V.D. Lomtadze shows that the main directions of engineering geology have been developed by many followers and have been recognized both at home and abroad. Three laws of engineering geology, proposed by V.D. Lomtadze in 1978, namely the law of geological correspondence, the law of accounting the dynamics of the earth crust and the law of detailed study of the geological environment have been confirmed in modern scientific research. At present there is some stagnation in engineering research due to the reduction in the rate of construction, and the primary statement of V.D. Lomtadze that engineering geology is aimed at solving problems of rational use and protection of the geological environment turns out to be true.
Statistical data on the reasons of buildings and structures transition to emergency and pre-emergency state are analyzed. In more than 60 % of cases the loss of stability of structures is observed as a result of activation of various factors acting during operation of buildings. The results of experimental studies showing the negative transformation of sand-clay soils under the influence of sewage runoff and the activation of microbial activity are presented. Empirical dependencies of changes in the coefficient of filtration of sands and strength of clayey soils when the bacterial mass increases are given. The role of organic pollutants in changing the redox conditions in the city underground space has been analyzed. The recommendation of the necessity to take into account the technology of industrial production in the practice of engineering surveys is given.
The influence of long-term radiation irradiation on changes in composition, physical and chemical activity and mechanical properties of Lower Cambrian blue clays serving as the base of low-activity waste storage facilities has been analyzed. It is shown that as a result of formation of defects in the crystal lattice of rock-forming and cementing minerals and their amorphization there is a significant decrease in the values of the total deformation modulus and shear resistance parameters, absorption capacity and swelling ability of clays increases 2 times. It was noted that the thickness of these clays is characterized by a high content of bacterial mass, which indicates active microbiological activity, especially in the upper part of the section.
Natural and technogenic factors determining the evolution and destabilization of the geo-ecological state of the underground space of St. Petersburg are analyzed. Special attention is paid to buried marshes, drainage network and groundwater pollution as the least stable parts of the underground space. The main pollutants of the city are sewage and buried wastes, which bring not only a large amount of organic substances easily assimilated by microorganisms, but also additional microflora. Since the mid-20th century, petroleum hydrocarbons are considered to be active pollutants in the underground space. Large amounts of organic matter in the underground space leads to the formation of a reducing environment and microbiological activation. Conducted mass sampling of redox potential, determining the features of the chemical composition of groundwater, as well as assessing the bacterial mass in sandy clay sediments of the section indicate the importance of physico-chemical and biochemical processes in the evolution and destabilization of the underground space of the city. As a result of these processes, negative transformation of dispersed soils, leading to the formation of floats, the active development of gas-dynamic phenomena, and a high level of environmental aggressiveness are observed. A special form of corrosion of building materials caused by the activity of microorganisms (bio-corrosion), which enhances chemical, electrochemical and other types of underground exposure, has been analyzed. It was found that more than 50 percent of the total destruction of underground pipelines, foundations, and basement walls is the result of bio-corrosion.
Проанализированы природные и техногенные факторы формирования окислительно-восстановительных условий в обводненной толще дисперсных пород. Показано влияние восстановительной обстановки и активности микробиологической деятельности на изменение состава и физико-механических свойств песчано-глинистых отложений. Приведены примеры трансформации пород при загрязне нии грунтовых вод и пород органическими компонентами.
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Хвосто- и шламохранилища, относимые к сооружениям промышленной гидротехники, входят в комплекс горно-промышленных предприятий, связывающих в единую и неразрывную систему добычу полезных ископаемых и их переработку, в том числе обогащение ...
Расширение добычи и переработки калийных руд требует увеличения площадей, занимаемых под складирование твердых и жидких отходов обогащения. В пределах Верхнекамского месторождения ежегодно отчуждается свыше 20-25 га ...
Количественный прогноз развития деформаций в основании сооружений должен базироваться на глубоком и всестороннем анализе процессов, которые протекают в породах основания при их взаимодействии с сооружением ...
Расширение производства калийных удобрений влечет за собой рост мощностей обогатительных фабрик. В связи с этим возникают серьезные проблемы охраны природных вод при складировании жидких отходов калийного производства ...
Оценка несущей способности глинистых пород как основания зависит от условий их консолидации б ходе строительства и эксплуатации сооружений. Выяснение возможности и характера уплотнения пород позволяет прогнозировать деформацию основания, изменение его прочности, правильно назначать показатели сопротивления сдвигу, выбирать схемы расчета осадок и оценивать устойчивость сооружений ...
Осадочные горные породы обычно имеют слоистое строение , причем прочностные характеристики на контактах слоев (сцепление с к и угол внут реннего трения ср к ) могут изменяться от нуля до их значений в материа ле слоя (с м И ф м ) ...
Прочность глинистых пород в значительной мере определяется содержанием в них воды и соотношением ее различных категорий. В настоящее время большинство авторов рассматривает виды категорий воды с точки зрения их формирования под влиянием энергетического поля глинистой частицы. Известно, что напряженность любого энергетического поля убывает по закону, близкому к экспоненциальному, поэтому переход воды из одной категории в другую является постепенным, плавным. При наложении поля частицы на воду структура ее искажается в связи с изменением характера трансляционного движения молекул воды ...
Геологический разрез кровли Ленинградского месторождения довольно сложен и характеризуется большим разнообразием литологических типов (от слабых глинистых горючих сланцев до весьма прочных известняков), их изменчивостью по расстояниям залегания от кровли промпачки и мощности. Наиболее опасной с точки зрения возможности обрушения является 90-сантиметровая пачка пород, считая от кровли промпласта, разрез которой наиболее сложен и обобщенно может быть представлен в следующем виде ...
Отличительной особенностью ленточных отложений является высокое значение их естественной влажности, обычно близкое или даже превышающее предел текучести породы. Вместе с тем ленточные отложения в природных условиях весьма далеки от текучего состояния (например, устойчивые откосы карьеров, вскрывающих ленточные отложения на полную мощность, устойчивость стенок шурфов, котлованов при условии сохранения их естественного сложения и отсутствии дополнительного увлажнения и др.) ...
В глинистых породах под действием определенного сдвигающего напряжения т развиваются во времени деформации ползучести. При значениях сопротивления сдвигу т, меньших некоторой величины деформации ползучести носят затухающий характер. При превышении деформации ползучести не затухают, причем в пластичных или мерзлых глинистых породах развитие их во времени приводит к разрушению пород. Чем больше величина сдвигающего напряжения, тем раньше разрушается глинистая порода ...