Hydrogeology and engineering geology MTPI

The laboratory provides the following services:

Determines the following physical and mechanical properties of cohesive soils and rocks:

I. For cohesive soils:

• 1. Density

• 2. Bulk density

• 3. Granulometric composition of gravel-pebble deposits

• 4. Granulometric composition of dispersed soils

• 5. Humidity

• 6. Hygroscopic humidity

• 7. Plasticity

• 8. Maximum molecular moisture

• 9. Swelling

• 10. Soaking

• 11. Compression tests

• 11. Compression tests

• 13. Shear testing of soils in their natural state with pre-compaction

• 14. Shear testing of soils in their natural state without pre-compaction

• 15. Shear testing of soils in a water-saturated state with preliminary compaction

• 16. Shear testing of soils in a water-saturated state without preliminary compaction

II. For rocks:

• 1. Density

• 2. Bulk density

• 3. Water absorption

• 4. Natural humidity

• 5. Porosity

• 6. Breaking strength

• 7. Compressive strength – in natural state

• 8. Angle of internal friction

• 9. Tractive resistance

• 10. Ultimate compressive strength in a water-saturated state

• 11. Softening factor

• 12. Strength coefficient according to Protodyakonov.

Laboratory develops methods and conducts research to study the engineering-geological and hydrogeological conditions of solid mineral deposits at different stages of exploration, measures to prevent the negative consequences of the development of engineering-geological processes and increase the stability of mine workings.

It performs research to determine the physical, mechanical and other properties of rocks to justify the design and construction of engineering structures.

The range of issues to be resolved in engineering-geological and hydro-geological studies at different stages of geological exploration.

• 1. Justification of opening methods and development systems, design of quarries and underground workings, projects for the organization of construction (ground, underground) works, assessment of the stability of rocks in slopes of opencast benches and sides of quarries, in underground workings and dumps, design of lining and selection of technological equipment, drainage systems , measures to prevent negative consequences during the development of deposits, properties of rocks and substandard minerals sent to dumps (acidity, salinity, content of chemically active and toxic substances, spontaneous combustion, etc.). They should be based on the conditions for the functioning of the binary system “geological environment – engineering works”: forecast of the conditions for the development of deposits (engineering and geological characteristics of rocks and their spatial variability, stability of rocks in the sides of quarries and underground workings, the nature of engineering-geological and hydrogeological phenomena in mine workings, features of mine workings watering, total water inflow, measures for draining mines and safe mining operations, assessment of the chemical composition of drainage waters); predictive assessment of the impact of mining operations and dewatering of the deposit on environmental objects (changes in the stress state of the mining and geological massif and the state of rock stability, the possibility of negative processes and phenomena in the deposit and adjacent areas, the development of a depression funnel, the nature of the regime of groundwater levels and the resulting changes in the hydrogeological conditions of the area, pollution of natural waters, the possibility of subsidence of rocks as a result of the deposit mining and waterlogging of the surface, etc.).

• 2. The watering of deposits that require preliminary and systematic drainage of aquifers, zones and complexes (forced measures used to ensure the stability of rocks in mine workings and the safety of mining operations) often significantly change the balance of groundwater, deplete their resources and violate the conditions of water supply to settlements , industrial facilities and agricultural activities, which are the most important tasks, not only from a hydrogeological point of view, but also concerning engineering geological study.

• 3. Assessment of the degree of technogenic changes in the geological environment in the zones of tailings and the state of stability of their dams with an assessment of the sedimentation of alluvial pulp, as well as typing by the harmfulness of hazardous wastes emitted and recommending additional volumes for storing industrial wastes, improving the state of the geological environment in the zones of tiailings influence.

• 4. Study and assessment of the state of the geological environment of “industrial desertification” of the territory of the mining regions of Uzbekistan: establishing the factors and causes of the formation of industrial deserts; identification of sources, types, degree of degraded-disturbed lands and the main negative components of industrial deserts; development of criteria for the formation of industrial deserts and recommendations for reducing the negative impact of the mining industry on the geological environment in industrial desertification zones.

• 5. Rational placement of dumps of waste rocks, substandard ores (disposal) of the after-run production, assessment and forecast of their stability, their impact on the state of hydrogeological and engineering-geological conditions of the underdump farm, as well as protection of adjacent territories from their harmful effects.

• 6. Questions about the possibility of using mine workings in depleted deposits or their individual sections for objects of various purposes (garages, warehouses, various manufacturing enterprises, etc.).

• 7. Development of proposals and recommendations for the rational use of the geological environment and its protection from the negative impact of mining enterprises.

• 8. The range of unresolved hydrogeological and engineering-geological issues related to the exploration and development of oil, gas and uranium deposits, which are envisaged in the future.

Currently, the laboratory of engineering geology and hydrogeology of the solid mineral deposits (SMD) conducts research and production work in the following areas:

• 1. Comprehensive engineering-geological and hydro-geological study of SMD at the stage of exploration work at the facilities of the State Committee for Geology and the AGMK and NGMK.

• 2. According to the theory of stability of mine workings, study of stress-strain state of the rock mass in connection with the formation of a quarry and an underground cavity; development of engineering-geological processes.

• 3. Use of the state of the rock mass of the deep horizons of the SMD and the forecast of the zone formation of engineering-geological processes.

• 4. Study of the water-physical and mechanical properties of quarry and dump soils on the dams of the reservoir of the Republic of Uzbekistan.

• 5. In the future, engineering-geological and hydrogeological work will be aimed at: – improvement of engineering-geological and hydrogeological methods for studying and predictive assessment of deep horizons of ore deposits in connection with the expansion of mining operations at great depths and an increase in the likelihood of complications; – improvement of the methodological foundations for studying the stress-strain state of the massif at various stages of exploration and development of a mineral deposit; – development of methods, apparatus and equipment for studying the properties and condition of the rock massif; – study and evaluation of hydrogeological and engineering-geological processes in connection with the exploration and development of the deposit, their forecast (type, location and distribution); – organizing and conducting monitoring of the geological environment in order to prevent adverse processes and phenomena; – study of hydrogeological and engineering-geological conditions of probabilistic mining waste disposal sites without much damage to the geological environment; – study and assessment of “drainage water” (groundwater involved in the watering of the SMD and attributed to associated minerals), its quality and reserves based on the intended purpose and stability over the period of water use (household and drinking, medicinal and extraction of useful components); – development of methodological foundations for forecasting to assess possible changes in the natural environment associated with the exploration and development of mineral deposits, as well as recommendations for taking these changes into account in the geological and economic assessment of the deposit.

• 6. Experimental studies are conducted to determine the long-term stability of rocks, the mechanism and dynamics of deformation development in deep mine workings using a bench model and long-term stability devices and a stabilometer.

The main scientific direction of the laboratory is the development of a theory that considers the conditions for the functioning of the binary system “geological environment – structures and engineering works”. The study of the operating conditions of the system involves the study, construction and operation of mines and quarries in difficult geological and tectonic conditions and ensuring the safety of mining operations. The trend of recent years in the development of the mining industry is involvement in the exploration and development of deposits characterized by more complex engineering and geological conditions and located at deep horizons. In this regard, the technogenic load on the geological environment increases, which leads to the development of unforeseen negative engineering and geological processes that complicate the development of deposits.

Main scientific results of the laboratory:

Peculiarities of engineering-geological conditions of deposits in mountain-folded areas in the Central Kyzylkum have been revealed. The main feature of the deposits is that ore bodies cross several lithological rock varieties at a large angle and are confined to zones of tectonic faults. They are characterized by frequent alternation of various lithological varieties, unsustainable in thickness and strike, wide development of zones of schistosity and crushing of rocks, the presence of different types of differently oriented faults. Lithological (for coal and phosphorite deposits) and lithological-tectonic (for all other types of deposits) principle of engineering-geological testing of rocks during exploration of deposits has been developed. The places, interval, number of sampling points depending on the stage of exploration are substantiated. A principle has been developed for compiling forecast maps of engineering-geological stability to changes in the natural environment during field development, based on a multi-parameter geomechanical classification of a rock mass. The main components of the rock mass (RM) are singled out depending on the specific gravity of each component, the appropriate “points” are established by the selection method. According to the numerical values of the total geomechanical parameters of the RM, the following categories of stability are distinguished: stable, medium stable, unstable.

-Stable with high engineering and geological potential: rocks are massive, weakly fractured (fracture voidness coefficient is less than 3%), strong (compressive strength is not lower than 50 MPa), low disturbance (disturbance coefficient is less than 5), water-resistant (softening coefficient is not lower than 0, 9), the shape of the structural block is favorable for stability (trapezoidal), the orientation of the main stresses is very gentle (less than 20 °) or the opposite direction with the side and mine workings, the total quality index is not lower than 75 points, the general angle of stable laying of the sides (up to the level of the erosion basis ) 50-60°.

Medium-stable, transitional, with an average engineering and geological potential: weakly and medium-altered, moderately fractured (fracture voidness coefficient 3-6%), softening coefficient 0.7-0.8, the shape of the structural block is oblique, medium and low strength ( ultimate compressive strength 35 – 50 MPa), total quality index not lower than 50 points, general angle of stable laying of sides (up to the level of erosion basis) 45-50°.

Unstable, with low engineering and geological potential: highly fractured (fracture voidness coefficient more than 6%), softening coefficient less than 0.7, the shape of the structural block is polygonal and shapeless, low and weak strength (compressive strength of 35 MPa or less), total the quality index is below 50 points;