Regional engineering geology: a history of the development of theory and methodology

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Theoretical aspects of engineering geology

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THE DISTRIBUTION CONDITIONS, THE COMPOSITION AND STRUCTURE OF THE SOILS OF THE KHARKOV SUITE OF PALEOGENE OF THE SOUTHEAST OF BELARUS

The deposits of the Kharkov suite of Paleogene of Belarus are the soils formed at the turn of existence and regression of the last sea basin and the final establishment of the continental situation in the territory of the country. They are widely spread in the south of the republic and lie mostly at depths of 100–110 m. In the southeast of Belarus, along the valleys of large rivers, these soils often reach the surface. The latter predetermined their active use as the foundations of structures. This is especially pronounced in the city of Gomel, where a wide development of territories is currently underway, within which these soils lie at depths of less than 10 m. The purpose of the work is to characterize the conditions for the distribution of the soils of the Kharkov suite of Paleogene within the southeast of Belarus and to study the characteristics of their composition and structure. The work is based on the results of the author's field and laboratory studies, which included a description of the outcrops, pits, and well cores; soil sampling; determination of their chemical and mineral, granulometric and microaggregate compositions, moisture characteristics for the classification of clay soils, as well as the results of statistical data processing. The paper presents the typification of the soil strata of the Kharkov suite of Paleogene of the southeast of Belarus, which allowed us to isolate three characteristic sites that differ in terms of their distribution, depth, thickness of the strata and composition of the soils. Nine granulometric sand and clay differences within the isolated areas were identified. The study of chemical-mineral and granulometric compositions of soils made it possible to identify their significant changes, both in area and in the section, which is caused by confinement to various facies zones, frequent migration of the coastline, long and uneven erosion and glacier-exaction destruction. The interrelation of the mineral composition, size and morphology of sandy soil particles is analyzed, it is noted that in all their varieties medium and fine sand fractions differ in the greatest mineral diversity.

TERMINOLOGICAL DICTIONARY ON FOUNDATION ENGINEERING, SOIL MECHANICS AND SOIL SCIENCE

Terminological dictionary on foundation engineering, soil mechanics and soil science.

THE SIZE OF THE SANITARY PROTECTION ZONE OF THE WATER INTAKE WELL IN THE LAYERED HETEROGENEOUS AQUIFER

Sanitary protection zones (SPZ) of water intakes allocate on the time of movement from the outer boundary of the zone to the water intakes. For example, for zone II it is the time of microbial contamination transport, accepted for target aquifers insufficiently protected from the surface, which is equal to 400 days. For zone III, this is the time of chemical pollution transport equal to the estimated lifetime of the water intake. To calculate the spatial position of the boundaries of these zones, analytical and numerical methods are used based on the integration of equations for the velocities of neutral particles in the groundwater flow, the flow field of which formed by the superposition of the natural flow velocities and the disturbances imposed on it by groundwater abstraction. When these methods are used, the only configuration of the sanitary protection zone that corresponds to some homogeneous or heterogeneous spatial field of hydraulic parameters obtained from field materials and (or) from the solution of the inverse problem is obtained as a result of calculations. At the same time, possible variations of SPZ boundaries are not considered due to local hydraulic heterogeneity, which is not taken into account in the water intake model. The article analyzes the influence of vertical hydraulic heterogeneity on the formation of sanitary protection zones in the layered heterogeneous aquifer. Random stationary fields of normally distributed logarithms of hydraulic conductivity were used as a basis for the model of hydraulic heterogeneity. As a result, the sizes of the first and second zones of sanitary protection were estimated and the comparative analysis of the received values with the sizes of SPZ was carried out, which were determined without taking into account model hydraulic heterogeneity. The analysis showed that the consideration of model hydraulic heterogeneity leads to a significant increase in the sanitary protection zones.