Darshan Institute of Engineering & Technology Engineering Geology Ch-1 Introduction By Agravat Rohit ( )

Introduction  Geology Geology is that branch of natural science which deals with the earth as a whole, regarding its origin, age, interior structure, history, evolution and modification of various surface like rivers, mountains and lakes along with their causes, minerals making up the earth, etc. Geology term has been derived from Greek words Geo (Earth) + lagos (Study of science)

Study of all water bodies existing on the surface or underground - the hydrosphere also forms an important part of geology The interaction of the atmosphere, lithosphere and hydrosphere, including the processes involved and results produced due to such an interaction also fall in the domain of the science of geology. Geology, also includes the study of various physical, dynamic and physico - chemical processes operating on or within the earth and of the agents and forces involved and evolved in such processes. Geology is rightly considered as one of the fundamental basic sciences like physics, chemistry and biology.

Geology Main branchesAllied branches 1.Physical geology 2.Mineralogy 3.Petrology 4.Structural geology 5.Historical geology (Stratigraphy) 6.Palaeontology 7.Economic geology 1.Engineering geology 2.Mining geology 3.Geophysics 4.Geohydrology 5.Geochemistry

 Main branches Branch deals with origin, development & various physical features on the surface of the earth like mountains, plateaus, valleys, rivers, lakes glaciers & volcanoes. This role play by internal agents (volcanism & earthquakes) & external agents (wind, water, ice & atmosphere) on the physical features of the earth makes a major part of study in physical geology. The structural disposition of the rock bodies & huge bodies of water & ice form other specific subject of study in physical geology. 1 - Physical geology

Study of minerals Basic units with different rock & ores. Details of made of formation, composition, occurrence, association, properties, uses, etc. of minerals are studied. i.e. quartsite, marble, calcite, hematite etc. Necessary for a civil engineer. 2 - Mineralogy

Petro – rocks logos – study Earth’s crust made up of Lithosphere. Deals with mode of formation, structure, texture, composition, occurrence, type, etc of rock. Rock is subdivided into three distinct branch 1.Igneous rock 2.Sedimentary rock 3.Metamorphic rock 3 – Petrology Deals with study of rocks

Earth’s crust undergo various deformation, dislocation & disturbances under the action of tectonic forces. As a results folds, faults, joints & unconformities in rocks. A details of mode of formation, causes, types, classification, importance, etc. ( Important in str. ) i.e. at a dam site, sedimentary rocks with upstream dip provided is desirable, while downstream geological this set up is most undesirable. 4 – Structural geology

Study of earth’s history through sedimentary rock. Stratigraphy = Strata + graphy Strata – the sets or beds of sedimentary rock graphy – description Study of rock indicate – time that has passes since their formation, thereby indication the life history of the rocks & its inhabitants. Its also involve extraction of fossils. i.e. remains of plants & animals of the past geological Eras. 5 – Historical geology (Stratigraphy)

Deals with the study of fossils, i.e. remains of plants & animals, extracted from sedimentary rocks Details of mode of formation of fossils, their types, occurrence, etc. from the subject of matter. Helps in providing a background to the development of life on earth, over the past geological ears. 6 – Palaeontology

Deals with study of rocks materials fuels etc. & its occurring on & in the earth that can be used for benefit of man. Include a wide variety of ores of all the metals & non-metal, building stone, salt deposits, fuel, industrial minerals for refractories abrasives & insulation Also its mode of formation, occurrence, classification, association, varieties, properties, concentration, use etc. 7 – Economic geology

 Allied branches Include the study of application of geology to civil engineering. Branch developed due to the interaction between the civil engineering practice & geological sciences. Branch deals with the geotechnical studies of the sites & sites & locations for major project like dams, tunnels, bridges, mountain roads. Etc. Also include availability of construction material. Role play in planning, design & construction of safe, stable & economic engineering projects. 1 – Engineering geology

Deals with the application of geological knowledge in the field of mining & quarrying. includes mode & extent of occurrence of ores, their association, properties. etc. Other physical parameters like depth, inclination (dip), direction (strike), thickness & reserve of ore bodies for efficient utilization. Above details of mineral exploration (purpose of discover), estimation & exploitation (eks,ploy’ty-shum) (productive) are dealt. Pre-requisite for the study of mining geology. 2 – Mining geology

The branch directly deals with the important principles. Processes & methods of physics are applied to solve many geological problems. Such like density & magnetism of the earth To know its interior, forms 3 – Geophysics Geophysics Pure geophysics General aspects of earth as whole Applied geophysics Study of upper layers of earth’s crust Foundation problems, alignment of structures, leakage problems along canals, locating building materials like stone etc.

Deals with occurrence, movement & nature of groundwater in an area. Existence & movement of ground water are directly related to porosity, permeability, structure, texture & composition of the surface & underground rocks. 4 – Geohydrology (hydrogeology)

Deals with the study of chemical properties of the earth as a planet & also of its various parts. Also deals with the occurrence, distribution, mobility, etc. of different elements in the earths crust. 5 – Geochemistry

Scope of geology 1.In civil engineering 2.In mining engineering 3.In ground water 4.In mineral exploration 5.In town planning

Application of geology in civil eng. Large structure like dams, tunnels, bridge etc. having the foundation on geological formation of the earth. safety, stability, economy & life of the structure are require. For above type of structure required material in very large quantities near the site (if not increase cost).

Application of geology in civil engineering (a)Planning (i)Topographic maps (ii)Hydrological maps (iii)Geological maps b)Design c)Construction

 Planning I.Topographic maps A maps which gives the details of different features & are essential to understand merits & demerits of all different possible site of making structure. Also include valleys (a long depression in the surface of the land that usually contains a river) & gorge (gorj) (a narrow pass (especially one between mountains)) can be easily computed from maps.

II.Hydrological maps Gives surface water & ground water & also with occurrence & depth of contours of water catchment area. III.Geological maps Rock types. Fracturing & displacement of rocks. Availability of construction materials.

b)Design Matter of designing an engineering project, the role of geological information is very important. i)Existence of hard bed rocks & their depth from & inclination with the surface ii)Mechanical properties along & across of site Compressive strength Shear strength Porosity & permeability Modulus of elasticity iii.On earth surface plane of weakness iv.Zone of weak material v.Ground water table vi.Seismic zone (earthquake zone)

c)Construction Selection of right type of material, which should be nearer to construction site of rock bed. Knowledge of quality control of material comes from the knowing basic properties of materials. In seismic region structure should light weight, for that light weight material used. Large structure like dam, bridge, tunnel – must have knowledge geology.