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.
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.
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.
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 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.
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.
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.
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 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.
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.
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.
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.
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.
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.
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.
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.
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 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.
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 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 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 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.
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.