GEOTECHNICS

as an important area of civil engineering, investigates the properties of the soil and rock environment, the interaction of this environment with new building objects, or their usability as a construction material. It encompasses interrelated specialisations such as soil mechanics, rock mechanics, engineering geology, building foundation, underground construction, earth construction. It is directly related to environmental protection, especially in connection with the movement of large quantities of solid materials, whether original or various wastes (spoil heaps, tailings, landfills, etc.).

From the point of view of a scientific discipline, geotechnics mainly brings together the following sub-disciplines of engineering:

• Geology, engineering geology and hydrogeology
• Geomechanics as a special discipline of mechanics, which includes the following theoretical disciplines
  • Soil Mechanics
  • Rock Mechanics
  • Mechanics of snow and ice – not taught here
• Application subjects:
  • Foundation Engineering
  • Underground Construction
  • Earth Structures
  • Special methods of foundation engineering
  • Foundations for reconstruction
  • Geotechnical task automation
  • Environmental geotechnics

Geology and engineering geology

Basic knowledge of geological disciplines is essential for safe and economical design of foundation structures, solution of stability of the territory, forecast of deformations of foundation soil, identification of causes of failures of building objects and design of their rehabilitation, evaluation of the impact of buildings on the environment and solving other tasks of construction practice. Together with other branches of geotechnics, geology enables the acquisition of reliable information on the properties of the rock environment, leading to its rational use. In the Czech Republic, geotechnical investigations of a typical construction project account for about 0.6% of the construction investment, while for complex engineering works (motorways, high-speed railways, dams, underground construction) it can exceed 2%. Errors and shortcomings in this survey have a negative impact on all phases of the life of the building, and the costs of remediation of failures as a consequence of inadequate geotechnical surveys often exceed the above values many times over.

Soil mechanics and rock mechanics

Soil mechanics and rock mechanics are theoretical disciplines for practical applications of geotechnical engineering (foundation engineering, underground construction, earth construction). The subject matter of the discipline of Soil Mechanics deals with issues related to the state of stress, mainly in terms of deformation, stability and, if necessary, failure of the foundation soil with respect to the presence and movement of water and the factor of time. An integral part of the mechanics of soils and rocks is the determination of their properties and behaviour under various conditions of stress. Therefore, the determination of the properties of soils and rocks under laboratory and field conditions is given considerable attention in the teaching of these subjects.

Foundation Engineering

Foundation engineering deals with the design and construction of foundations. It is an interdisciplinary science using knowledge from geology, engineering geology, soil mechanics, structural mechanics, building materials, etc. Despite the fact that the foundation of buildings is based on calculations and uses limit state methodology, it requires intuition and engineering sensitivity. Therefore, in teaching this subject, emphasis is placed on the student’s independent thinking, on his ability to find the essential one out of many problems. Computer technology is used in the teaching, but the ability for independent reasoning resulting from knowledge of the above fields is crucial. Of particular importance is the technology of building foundations, which is developing rapidly and to some extent determines the cost and efficiency of building foundations. The cost of foundations for ordinary buildings is between 15 and 20 % of the total construction costs, while for complex engineering structures (dams) it exceeds 50 %, and for special structures (waste storage facilities) it can reach up to 90 % of the total cost. Graduates of civil engineering studies (K and V) are best employed in foundation-related activities – K and S majors offer a diploma thesis in foundation. Master theses focus on the design and economic assessment of foundations for civil, industrial and bridge structures; design and assessment of construction pits in urban development; design and assessment of special geotechnical structures.

Underground Structures

Underground construction is developing rapidly around the world. This tendency is beginning to manifest itself in the Czech Republic as well. Underground construction is experiencing an extraordinary growth in highly urbanised environments, in connection with the necessary environmental protection and the requirements for the demanding routing of modern linear structures (metro and underground rapid transit lines, urban, road and motorway tunnels, underground car parks, high-speed railway tunnels). The establishment of special underground storage and storage facilities (for liquid and gaseous hydrocarbons, refrigeration and freezing facilities) is becoming a very frequent issue. Especially in cities, major renewal of utility networks is necessary (water mains, sewerage collectors, establishment of combined lines – collectorisation); wastewater treatment plants are increasingly being placed underground. In connection with the development of the industry and the use of the lithosphere, there is a need for planning in the space below the surface (underground urbanism). The field has changed completely technologically in the last 20 years or so and can be described without exaggeration as a field for the 21st century.

It is only taught in its entirety in the K programme – it is possible to do a diploma thesis in it (usually in the field of transport – i.e. road or railway – tunnels, or municipal underground structures – i.e. sewer collectors or collectors).

Career of graduates of the specialization “Geotechnics” (K programme):

• geotechnical survey – monitoring of demanding civil engineering structures
• work in geotechnical laboratories
• investor activities in the field of civil engineering structures
• design of geotechnical structures and special foundations
• carrying out work in the field of special foundations as a foreman, later as a construction manager or specialist
• special engineering activities focused on complex civil engineering structures

Geological collections of the Institute of Geotechnics

The collection of building and decorative stones is one of the best in Europe. It comprehensively documents the rock types used in European architecture during the 20th century. It contains about a thousand exhibited samples, 6,500 samples are in the depository.

The mineralogical collection, containing historical unique specimens from many European sites, comprises about 2,000 samples, of which about 400 are on display.

The petrographic collection documents the variability of rock and soil types as the foundation soils of Central Europe, with an emphasis on the Czech Republic. It includes about 300 exhibited samples.

Geology classroom

Specialized geology classroom enabling active work with samples representing the basic types of rocks and soils forming the foundation soils of the Czech Republic or used as building and decorative stone. Examples of successful seminar papers are exhibited here, which students prepare on the basis of their own fieldwork and observations, and thus learn in an active way the basic principles of construction geological research.

Soil Mechanics Laboratory

The Soil mechanics laboratory is used primarily for laboratory teaching of geotechnical disciplines, but also for research projects, experiments, obtaining input values for PhD students’ dissertations and special practice tasks.

The laboratory is fully equipped with instruments for the determination of all soil properties, both physical index and mechanical.

For special tests, a fully automated system has been developed at the Institute of Geotechnics to perform both standard and non-standard shear triaxial tests with sample saturation under isotropic or anisotropic consolidation. Automatic data acquisition is also implemented for the shear box instrument and the edometers.

Computer classroom

The following computer programs are available in the computer room of the Institute of Geotechnics for teaching and solving dissertations of PhD students:

GEO4 software is designed for calculation of foundation structures according to ČSN. This package contains sub-softwares that solve only a specific foundation problem.

PLAXIS is a software designed specifically for the calculation of deformation-stress problems in geotechnical engineering based on the finite element method.

The RIBTEC software package is designed for the calculation of 2D problems using the finite element method. It is also specialized for geotechnical tasks.

ANSYS is a general-purpose program based on the finite element method. This program is not specifically developed for geotechnical problems, but allows to solve any problem defined by the user.

The FLAC program is based on the differential numerical method. It is suitable for solving material nonlinear calculations and modelling of overstrain under large deformations.

Physical Modelling Laboratory

The physical modelling laboratory was built in 1973. A detailed study of the mechanical behaviour of geomaterials is essential for solving important geomechanics problems, e.g. for modelling the interaction between structure and soil. There is a tendency in the world to investigate the above-mentioned problems on models using centrifuges, in our country mainly using physical models. At present, our Institute is the only institute in the Czech Republic dealing with this challenging problem of solving complex geomechanics problems using physical models. More than 50 physical models have been built here since 1973 as part of scientific and research activities.

Information can also be found in the document (available in Czech only).