1 [1] Engineering Geology (EC 101) [1] Dr SaMeH Saadeldin Ahmed Associate Prof. of Environmental Engineering Civil and Environmental Engineering Department College of Engineering - Majmaah University (Feb. 2014) Dr. SaMeH CE 101

2 Contents Part 1 1- Definition of Earth Sciences 2- Minerals 3- Rocks 4- Structural Geology 5- Earthquakes 6- Groundwater Dr. SaMeH CE 101

3 Part 2 M echanical Properties of Rocks T unnels F oundations and Engineering Applications

4 1. Definition of Earth Sciences 1. Definition of Earth Sciences Dr. SaMeH CE 101

5 Definition of Earth Sciences Earth sciences are dealing with the study of the constituents of the earth crust from the following point of view: Chemical composition, properties of natural minerals, external and internal processes that affect the earth since and its inception evolution of all life, whether animal or vegetable. The word Geology is derivative from the Greek language and consists of two parts: “Geo = Earth” and “logos = science”. Dr. SaMeH CE 101

6 Main Branches of Earth Sciences The main branches are: 1.Geochemistry 2.Geophysics 3.Dynamic Geology 4.Historical Geology 5.Applied Geology Dr. SaMeH CE 101

7 1.1 Geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks, water, and soils, and the cycles of matter and energy that transport the Earth's chemical components in time and space, and their interaction with the hydrosphere and the atmospherechemicalEarthplanets rockswatersoilshydrosphereatmosphere Dr. SaMeH CE 101

Some subsets of geochemistry are: Isotope geochemistry (Crystallization)Isotope geochemistry Mineralogy Rocks Biogeochemistry Aqueous geochemistryAqueous geochemistry Dr. SaMeH CE 1018

9 1.2 Geophysics is the physics of the Earth and its environment in space.Earth The term geophysics refers to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. Geophysical survey data are used to analyze potential petroleum reservoirs and mineral deposits, to locate groundwater, to locate archaeological finds, to find the thicknesses of glaciers and soils, and for environmental remediation.geologicalshapegravitationalmagnetic fieldsinternal structurecompositiondynamicsplate tectonicsmagmasvolcanismGeophysical survey Dr. SaMeH CE 101

The most common Geophysics methods are: 1.Gravity 2.SeismologySeismology 3.Electricity 4.Magnetism Dr. SaMeH CE 10110

Dynamic Geology 1.3 Dynamic Geology This section includes studies on the geological processes that occur on the surface of the earth, which called external processes such as physical and chemical weathering of rocks, sedimentation in seas and lakes and rivers and surface water study. As well as the geological processes that originate within the Earth, known as internal processes such as: the study of earthquakes, volcanoes and geological structures arising from earth movements Dr. SaMeH CE 101

Historical Geology is the use of the principles of geology to reconstruct and understand the history of the Earth. It focuses on geologic processes that change the Earth's surface and subsurface; and the use of stratigraphy, Ancient geography and paleontology to tell the sequence of these events. It also focuses on the evolution of plants and animals during different time periods in the geological timescale.geologyhistory of the Earth stratigraphypaleontologyevolution plantsanimalsgeological timescale Dr. SaMeH CE 101

Applied Geology This section includes important application of the foundations of Earth Sciences and geological information to exploit the mineral resources of raw materials and oil, etc. which are terrestrial crust economic exploitation for the benefit of rights and the progress of civilization. Dr. SaMeH CE 101

One of the main sections of Applied Geology : Mining Geology, Petroleum Geology, Groundwater, Geology of radioactive isotopes, Engineering geology and Environmental geology. Dr. SaMeH CE 10114

Dr. SaMeH CE Applied Geology Historical Geology Dynamic Geology GeophysicsGeochemistry Mining geologyPaleontologySedimentationGravityCrystallization Petroleum geologyStratigraphyOcean logySeismologyMineralogy Economic geologyGeographyMagmaElectricityRocks Geology of radioactive isotopes VolcanologyMagnetism Chemistry of Earth Groundwater geology Earthquakes Engineering geology Structural geology Environmental geology

16 Importance of earth sciences 1. Earth Sciences provide engineers with essential information on the physical and mechanical properties and the required tests for the type of materials forming the crust. 2. There is a need to study the properties of the rocks in order to design foundations and conducting the right constructions such as dams, tunnels, mines, surface and subsurface structures and main roads. Dr. SaMeH CE 101

17 3. It almost impossible to carry out correct and safe excavations in rocks without identifying their natural and mechanical characteristics, as well as to understand the type of geological structures that are found in such rocks. 4. Study the geology and ground water movement is very useful in identifying sources of water. Also it is useful for irrigation and drainage engineering works for sanitary. Dr. SaMeH CE 101

18 5. Structure geology is important for protection from landslides. 6. Knowledge of the principles of geological engineer for surface water such as rivers and seas and the role they play as agents of erosion, transport and sedimentation, greatly help in solving some problems related to adjust edges and course of rivers. Also –Strengthening bridges in case of flooding and other engineering projects. –Preservation of the environment. Dr. SaMeH CE 101

7. Mastering engineer to read and interpret reports, geological maps and aerial photos is of great benefit in areas of urban planning and select sites for airports, highways, facilities and location of construction materials and road construction. 8. In some projects, it is vital to study the rocks beneath the surface before choosing a site engineering works. Such studies can be useful for limitation of field works and utilizing all the information and data contained in the report and geological maps and geological profiles. Dr. SaMeH CE 10119

20 Quiz 1…Next week Thanks for your attention Dr. SaMeH CE 101