Geology is the science of the earth. It represents a whole complex of scientific disciplines and industrial branches related to the study of the earth's crust and its deeper spheres. The tasks of geology are mainly aimed at understanding the laws governing the formation and distribution of mineral deposits (mineral deposits). Most of the specific issues addressed in modern geology relate to depths of the order of 10-15 km, due to the geological depth of the cut in the areas of ancient folding and the current level of technical capabilities for mining and exploration of minerals.
General concepts
Engineering geology is a scientific and technical branch of geology that studies the features and patterns of interaction of the geological environment with engineering structures. The object of engineering geology is the upper layers and horizons of the earth's crust, the geological conditions for their formation and occurrence, morphological, strength and dynamic characteristics in connection with human engineering activity.
Along with highly specialized tasks, engineering geology provides for the study of geological composition, soil properties and composition, hydrogeological conditions, destructive geological processes and a number of other issues. Therefore, the fundamentals of engineering geology include the need for certain broad knowledge in a number of related geological disciplines, including general geology, mineralogy, geomorphology, hydrogeology, petrography, tectonics, geophysics, etc.
Targets and goals
Geotechnical surveys aim to carry out a comprehensive and comprehensive assessment of geological factors caused by human activities in the construction and economic sphere, in conjunction with natural geological processes.
The main tasks of engineering geology, including the study of geological-tectonic, geomorphological, seismic and technogenic factors, focus on the development of engineering-geological justification, which without fail precedes the construction of facilities with the status of engineering structures. These are civil and industrial buildings and structures, roads and railways, dams, bridges, airfields, subways, underground workings, underground utilities and many other objects.
Thus, engineering geology is designed to provide designers, builders and maintenance services for economic facilities with all the data necessary for the design and construction, as well as for the implementation of activities related to their operation.
Based on the results of engineering and geological work, they make a conclusion on the fundamental possibility of building structures and buildings or determine the most favorable sites for their placement. The conclusion should contain recommendations on the preferred method of work, proposals for designs in terms of their maximum reliability and preventive measures to combat possible negative geological processes that could threaten the safety of the building or structure.
Main sections of engineering geology
Being a part of geology as a science, engineering geology, in turn, includes a number of independent disciplines, of which engineering geodynamics, soil science and regional engineering geology are considered the main ones.
Soil science, as the name implies, is the scientific branch of engineering geology, which knows the structure, composition and properties of soils, the laws of their formation and accumulation, as well as the peculiarities of spatio-temporal variability due to the engineering, construction and economic activities of people.
The object of engineering geodynamics is a wide range of today's geological processes that have a significant impact on the conditions for the construction and operation of economic facilities of any scale. Such processes include earthquakes, landslides of various origins, dips, subsidence, cracks, etc. Along with research and forecasting, they all necessitate the development of protective and protective measures, which also relates to the tasks of engineering geodynamics.
Regional engineering geology, like others engineering and geological surveys, studying the features and patterns of development of the uppermost layers of the earth's crust, which make up the so-called lithosphere, in connection with the current and planned engineering, economic and civil engineering activity of man. But the subject of regional engineering geology is, by definition, geological factors of a regional scale.
Physico-mechanical properties of rocks and soils
To carry out design and construction work, the study of the physicomechanical parameters of rocks and soils is of paramount importance, since a lot of fundamental decisions depend on the design indicators of strength, reliability and durability of the base of the construction object, related to the choice of the structure of the structure, its size, type, as well as the determination of volumes construction and related works. In this regard, the physical and mechanical properties of rocks and soils are necessarily analyzed at all stages of engineering and geological surveys.
The physical and mechanical parameters of rocks and soils include the following indicators: particle size distribution , plasticity, particle density, moisture, addition density, shear resistance, uniaxial compression strength, angle of repose, petrographic composition, subsidence, swelling and shrinkage, elastic modulus, coefficient soil pressure, deformation modulus, suffusion leaching, Poisson's ratio, salt content, filtration coefficient, water absorption, water saturation and a number of additional parameters.
An assessment of the engineering and geological properties of rocks and soils is invariably accompanied by a study of the material and chemical composition, as well as structural and texture features.
The composition and staging of engineering and geological research
Geological engineering surveys consistently include reconnaissance , geological engineering surveys, geological engineering surveys, detailed work during construction, and final surveys upon completion.
Reconnaissance is a comprehensive assessment of geological and geophysical knowledge in order to determine the feasibility of further, more detailed work. If the geology of the region is sufficiently well studied where engineering geological surveys are planned, work can begin immediately with engineering geological surveys.
The survey is performed to study geomorphological and hydrogeological features, engineering and geological properties of rocks and soils, manifestations of active geological processes and a general assessment of engineering and geological conditions in the area of the planned construction work.
Based on the results of exploration work, design estimates and working documentation are compiled.
The content of production engineering and geological research
A typical set of engineering and geological surveys, as a rule, includes the following types of work :
- preliminary desk processing of the collected materials;
- study of aerial photography materials;
- route research;
- geophysical work;
- mining operations, including well drilling;
- field testing of rocks and soils;
- hydrogeological observations;
- stationary research;
- laboratory works;
- diagnostics of the state of buildings and structures under construction;
- full office processing of the collected materials;
- writing a final report with the presentation of graphic materials, recommendations and conclusion.
Final results of engineering and geological surveys
Summarizing the material presented, it may be appropriate to list the specific and understandable results of engineering and geological research.
So, based on the totality of the data of geotechnical work, the following parameters are calculated and provided:
- the stability of the rocks of the base of the structure to deformation, which leads to "bulging" from under the foundation;
- the degree and timing of the compression of rocks and soils at the base of buildings and structures;
- the stability of rocks and soils in the slopes of quarries, construction pits, road ditches, embankments, ditches, channels and other artificial excavations;
- the stability of hydraulic structures (for example, dams) to shear deformations under the pressure of reservoir water;
- forecasting coastal behavior after the construction of reservoirs;
- the stability of the foundations of buildings and structures during the rise of groundwater;
- sustainability of engineering structures erected on permafrost, in seismic hazardous areas, in the areas of development of karst cavities, landslides, landslides and other natural disasters.
Regulations
Engineering and geological production work is carried out in accordance with the technical requirements set out in the list (set) of survey rules to justify design preparatory measures before construction, as well as for ongoing surveys carried out in the process of construction and operation of facilities until their liquidation.
The marked list of normative guidelines for the production of geological engineering surveys includes a number of building codes and rules (SNiP) that regulate the performance of work in the manner prescribed by state regulatory and legislative acts.