Complete Lectures CE-220 Geology for Engineers PDF

CE-220 Geology for Engineers (S.E) Department of Civil Engineering LECTURE # 01 Course Teacher: Ms. Sadia Moin FOR CE-220 (B) BOOKS  F.G.H. Blyth & M.H. de. Freitas, A Geology for Engineers, 7th Edition, Edward Arnold ltd. Publisher, 1984  P.B. Attewell & I.W. Fa...

CE-220 Geology for Engineers (S.E) Department of Civil Engineering LECTURE # 01 Course Teacher: Ms. Sadia Moin FOR CE-220 (B) BOOKS  F.G.H. Blyth & M.H. de. Freitas, A Geology for Engineers, 7th Edition, Edward Arnold ltd. Publisher, 1984  P.B. Attewell & I.W. Farmer, Principles of Engineering Geology, 1st Edition, Champan and Hall ltd. Publisher, 1976  S. Stein & M. Wysession, an introduction to seismology, earthquakes and earth structures, 1st edition, Blackwell publishing ltd., 2003 SESSIONAL MARKS 5 marks for activity portfolio 5 marks for a quiz / test 20 marks in mid term (half covered from CE-220 A and Half from B) Remaining 10 marks sessional provided by Dr. Sadaf CLOS DISTRIBUTION COURSE OUTLINE CHAPTER 1: General Geology, definition and scope CHAPTER 2: Structural geology CHAPTER 3: Crystallography CHAPTER 4:Applied Geology CHAPTER 5: Rock Classification CHAPTER 6: Earthquakes COURSE CONTENT CHAPTER 1 GENERAL DEFINITIONS AND SCOPE 1- INTRODUCTION & DEFINITIONS 2- EARTH AS A PLANET 3- THEORY OF ISOSTASY WHAT IS THE DIFFERENCE BETWEEN GEOLOGY AND ENGINEERING GEOLOGY? Geology is basically the study of earth. Engineering Geology is related to the applications provided by the engineers to different structures based on the geology of the area. DIFFERENT BRANCHES OF GEOLOGY a) Physical geology (current & near g) Historical Geology past) h) Economic Geology (gold etc.) b) Structural geology (forces) i) Engineering Geology c) Sedimentology (sediment process) j) Hydrogeology (water) d) Mineralogy (minerals) e) Petrology (rocks) f) Paleontology (fossils) one two three four Geological Process Geological Agents weathering Erosion Wind Transportation Deposit- Water ion Heat & pressure EROSION SEDIMENTATION the action in which soil removes the tendency of the particle to from one location under the remain settle as a sediment. It action of wind, water, etc. and may be due to deposition or then transport it to another precipitation. location. ACTIVITY 1 Mention through figure that how the geological process are connected with each other How the rivers are making their path change, which geological process plays an important role in it. Briefly explain it.  CE-220 Geology for Engineers (S.E) Department of Civil Engineering LECTURE # 02 CE-220 (B) ORIGIN OF EARTH SECTION OF EARTH EARTH AS A THEORY OF ISOSTASY PLANET ORIGIN OF EARTH From different studies Scientists have found that the early Earth would have been an unsorted mixture of materials, growing as it gathered up smaller objects in its path. During this time, the heavier materials sank towards the center, creating the core, and the lighter materials rose to the surface, creating the mantle and the crust. This process of separation is called differentiation. Earth Section and Different Layers Description Section Of Earth Inner Core: Most Denser Layer; possibly made of pure iron and Nickel Outer Core: It is less dense than inner core; probably consist of lighter elements like oxygen, sulfur or carbon Mantle: It is made up of silicate materials like basalt, olivine, and pyroxene. Aesthenosphere: Highly viscous and ductile region of earth made up of viscoelastic solid. Lithosphere: It consist of continental crust and oceanic crust A material that possesses characteristics of a liquid substance, alongside of attributes of a solid substance. THEORY OF ISOSTASY ISOSTASY: It is the state of gravitational equilibrium between crust and mantle. It gives an idea that lighter crust must be float on the denser underlying material or mantle. There are the two theories regarding Isostasy Pratt’s theory Airy’s theory PRATT’S THEORY AIRY’S THEORY Lateral changes In rock density across the According to Airy, the rock density is lithosphere. approximately same but the crustal blocks Assuming that the mantle below is uniformly have different thicknesses. dense and the less dense crustal blocks floats Mountains that shoot up higher also higher to become a mountain. extends to the deeper roots in to the denser material below. And the more dense blocks will form low lands and basins. DENUDATION Land areas are being reduced and their shape modified by weathering and erosion. The general term used for this process is known as Denudation.  DIASTROPHISM It is also called as tectonism. It refers to the twisting of earth surfaces. Large scale deformation of earth crust by natural processes which leads to the formation of continents and ocean basins.  CE-220 Geology for Engineers (S.E) Department of Civil Engineering LECTURE # 03 CE-220 (B) INTRUSIONS 1- BATHOLITH 2- LACCOLITH 3- LOPOLITH 4- DIKE 5- SILL INTRUSIONS A laccolith is a body of intrusive rock with a dome-shaped upper surface and a level base, fed by a conduit from below. A laccolith forms when magma rising through the Earth's crust begins to spread out horizontally A batholith is a large mass of intrusive igneous rock, larger than 100 km² in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, such as granite, quartz monzonite, or diorite ACTIVITY 2 Draw all types of intrusions in a single picture and label it clearly. Write one line definition or identification of each intrusion. SUMMARY OF CHAPTER 1 Difference between Geology and Engineering Geology. Branches of Geology Geological Process and Geological agents Origin Of earth Internal section of earth Denudation & Diastrophism Intrusions CRYSTALLOGRAPHY AND MINERALOGY  Crystal TOPICS Mineral COVERED IN Criteria for the mineral TODAY’S LECTURE Occurrence of Minerals Elements of Crystal CRYSTAL crystals are the bodies of geometric shape which are bounded by the faces arranged in a regular manner and related to internal atomic structure. Iridescent Mineral Selenite crystal cluster MINERAL  It can be defined as a natural inorganic substance having particular chemical composition and a regular atomic structure.  Substance which having the following five criteria is known as mineral. Solid Naturally occurring Inorganic Fixed chemical formula Specified atomic structure OCCURRENCE OF MINERALS Minerals occur as crystals i.e. bodies of geometric shapes which are bounded by faces arranged in a regular manner and related to internal atomic structure. Volcanism CRYSTAL FACE AND CRYSTAL FORM CRYSTAL EDGE, VERTICES SOLID ANGLE AND INTERFACIAL ANGLE GONIOMETER DISTORTION COMBINATION Crystal develop faces of different If a crystal is bounded by dissimilar shape and size. This one is known as or unlike faces then it is termed as distortion. combination.  CE-220 Geology for Engineers (S.E) Department of Civil Engineering & (S.E) Department of Civil Engineering along with specialization in Construction LECTURE # 04 Course Teacher: Ms. Sadia Moin CRYSTALLOGRAPHIC AXES CRYSTAL GROUPS Isometric Isodiametric Anisometric SYMMETRY PLANE OF SYMMETRY The faces, edges and solid angles It is an imaginary plane which in crystals occurs with divides the crystal system in two regularities and this is known as equal halves. symmetry. CENTER OF SYMMETRY Crystal is said to possess a center of symmetry if on passing an imaginary line from some definite face, edge or corner. Many crystals have no plane of symmetry, but they possess center of symmetry ASSIGNMENT / CLASS ACTIVITY Draw a table in such a manner that have column of crystal name, crystal shape, crystal group, crystallographic axes and mention its angles and sides, etc. in the same manner as mentioned in the previous slide and also make a column of example and search any mineral name who have that specified crystal structure (like quartz having hexagonal crystal system; so in the tab of example you can write quartz in front of hexagonal crystal system) Represent the plane of symmetry of every crystal system separately (proper scaled diagrams)  CE-220 Geology for Engineers (S.E) Department of Civil Engineering & (S.E) Department of Civil Engineering along with specialization in Construction LECTURE # 05 Course Teacher: Ms. Sadia Moin  Crystallographic axes Crystal system QUICK RECAP OF PREVIOUS Crystal groups LECTURE Plane of symmetry Center of symmetry TODAY’S LECTURE Mineral Occurrence & Importance of minerals Physical properties of mineral MINERALS Substance which having the following five criteria is known as mineral. 1. Solid 2. Naturally occurring 3. Inorganic 4. Fixed chemical formula 5. Specified atomic structure IMPORTANCE OF MINERAL Iron is important for construction, transportation and construction of different equipment. Copper use for wiring as well as for making utensils. Gold, silver, Nickel, rock salt, etc. OCCURRENCE OF MINERAL Mineral is obtained by natural process One common natural process is crystallization of magma Normally they found in faults, cracks and on seabed or ocean floor The smaller occurrences are called veins and larger are called lodes. PROPERTIES OF MINERALS This includes color, luster, hardness, cleavage, fracture, tenacity, habit, streak, diaphaneity, magnetic property, specific gravity. Except this some minerals have their own property which is named as special property. For example, Sulphur having property of odor or a pungent smell, magnetite having special property of magnetism PHYSICAL PROPERTIES OF MINERAL Color Tenacity Luster Habit Hardness Streak Cleavage Diaphaneity Fracture PHYSICAL PROPERTIES OF MINERAL COLOR LUSTER PHYSICAL PROPERTIES OF MINERAL CLEAVAGE PHYSICAL PROPERTIES OF MINERAL FRACTURE conchoidal (curved), Even (nearly flat), uneven (rough) and hackly (small sharp irregularities). PHYSICAL PROPERTIES OF MINERAL HABIT TENACITY PHYSICAL PROPERTIES OF MINERAL STREAK DIAPHANEITY PHYSICAL PROPERTIES OF MINERAL HARDNESS Practical Hardness Scale Practical Hardness scale Fingernail - 2.5 Moh’s Hardness scale Copper coin – 3.5 Iron nail- 4.5 Sharp glass- 5.5 Streak plate – 6.5  CE-220 Geology for Engineers (S.E) Department of Civil Engineering & (S.E) Department of Civil Engineering along with specialization in Construction LECTURE # 06 Course Teacher: Ms. Sadia Moin TODAY’S LECTURE i. Moh’s hardness scale ii. Special Properties of mineral iii. Rock forming minerals iv. Bore log v. Geologic Time scale MOH’S HARDNESS SCALE MINERAL HARDNESS TALC 1 GYPSUM 2 CALCITE 3 FLUORITE 4 APATITE 5 FELDSPAR 6 QUARTZ 7 TOPAZ 8 CORRUNDUM 9 DIAMOND 10 SPECIAL PROPERTIES MAGNETISM DOUBLE REFRACTION When a light enters in crystal and separate in two different rays (mica, quartz, etc.) SPECIAL PROPERTIES FLOURESCENCE (sodalite, apatite, etc.) PHOSPHORESCENCE (light emitted by a substance without combustion or perceptible heat. E.g: celestite and willimite) PIEZOELECTRIC (electric charge produce in the result of applied mechanical stress e.g topaz, tormalline) ROCK FORMING MINERALS Olivine Quartz Amphibole Mica Feldspar Pyroxenes Calcite pyrite OLIVINE Most common mineral group in igneous rock, occurred in rounded shape, normally transparent or translucent in yellow-green color. Such as in basalt, gabbro etc. QUARTZ Quartz is a glassy looking, transparent or translucent mineral which varies in color from white and grey to smoky. When there are individual crystals they are generally clear, while in larger masses quartz looks more milky white. Quartz is hard. In many rocks, quartz grains are irregular in shape because crystal faces are rare. AMPHIBOLE The most common amphibole is hornblende. Hornblende is quite similar to augite in that both are dark minerals, however hornblende crystals are generally longer, thinner and shinier than augite and the mineral cross-sections are diamond-shaped. MICA Mica is easily distinguished by its characteristic of peeling into many thin flat smooth sheets or flakes. This is similar to the cleavage in feldspar except that in the case of mica the cleavage planes are in only one direction. Mica may be white and pearly (muscovite) or dark and shiny (biotite). FELDSPAR Feldspar is the other common, light-colored rock-forming mineral. Instead of being glassy like quartz, it is generally dull to opaque with a porcelain-like appearance. Color varies from red, pink, and white (orthoclase) to green, grey and white (plagioclase). Feldspar is also hard but can be scratched by quartz. Feldspar in igneous rocks forms well developed crystals which are roughly rectangular in shape, and they cleave or break along flat faces. PYROXENE Minerals in the pyroxene group are abundant in both igneous and metamorphic rocks. The most common pyroxene mineral is augite. Augite is generally dark green to black in color and forms short, irregular shape crystals. CALCITE: Calcite is a very common mineral in sedimentary rocks. It is commonly white to grey in color. Individual crystals are generally clear. In a rock, calcite grains are often irregular in shape. Calcite's major distinguishing characteristic is fizz test in which calcite reacts with dilute hydrochloric acid and produces bubbles. Dolomite is very similar to calcite but does not react well with acid unless powdered first. It contains carbonates of magnesium with calcite. PYRITE The group contains sulphide minerals in common, i.e. those minerals containing sulphur as a principal component. It occurs in all rock types, though usually only in small amounts. It is a pale brassy yellow in color with a metallic luster and often forms cube-shaped crystals. Also known as "fool's gold". CLASS ACTIVITY Observe the following minerals and make a page in your lecture copy and write their physical properties color, habit etc. BORELOG Bore log is usually small diameters holes which are providing the opportunity to physically remove soil or rocks for the testing. MAKE A BORE LOG REPORT the bore done in the area of Nooriabad for construction of building by using mechanical drilling of steam auger up to a depth of 5m with weight of 30 pounds. The excavation started and it shows at a depth of 2m there is only loose sand available with a moisture content of 5% and unit weight of 18.5 pcf. After the depth of 2 m there is an strata which have a thickness of 3m which comprised of compacted gravels are available but the gravels available after 4m are highly wet. The moisture content and unit weight of dry part is 3% and 20.5 pcf respectively while the wet part is having moisture content of 12% and unit weight of 31 pcf.  PREPARE A BORE LOG REPORT FROM THE GIVEN DATA ASSUME IF YOU THINK ANY IMPORTANT INFORMATION IS MISSING Company “ABC” did the bore on request of client “XYZ”. The area for which the bore log required is a place near Quetta, Balochistan. Company did a bore on 8 dec, 2023 and they found that they cannot apply blows in the first 2 ft strata because of the presence of Soft soil, so they did it manually, the density and moisture content of that soil are 11 pcf and 1% respectively. After that 2 ft boring start by the help of mechanical steam auger the driving weight and height is 20 pounds and 5 ft. On the application of 20 no of blows, initial 3 ft showed silty clay soil with some part of gravel, its density found as 12 pcf and moisture content measured as 8%, after that strata, on the application of 35 blows, sampler provided a thick compacted layer of sand which is 2 ft thick and 1 ft after that layer is comprised of gravel and pebbles. The density of sand was 18 pcf and moisture was 9% while gravels and pebbles give the density of 25 pcf and the moisture was 12%. The highly wet layer of loose pebbles achieved on 30 no. of blows, having thickness of 3 ft and achieved at the end of the bore, that one is having a moisture content of 68% and density of 18 pcf. UNCONFORMITY Unconformity indicates history of rock formation, Diastrophism, erosion and deposition of sedimentary rocks. Unconformity is a former land surface now buried by younger rock representing gap in the rock record Mismatching in rock layers.  STRATIGRAPHY It is a branch of geology that deals with the rock succession through time. Largely based on the law of superposition. Two major types of stratigraphy are Lithostratigraphy Biostratigraphy WHY IT IS IMPORTANT TO STUDY? This field is important to understanding the geological history and forms the basis for classification of rocks into distinct units that can be easily mapped. The civil engineers need to know the properties of rocks accurately to enable them to consider different rocks for any required purpose that is as a foundation rock, as road metal, as concrete aggregate, as building stones or as the roofing material for decorative purpose. BASIC PRINCIPLES OF STRATIGRAPHY Law of Superposition Law of original Horizontality Law of lateral continuity Law of crosscutting relationship Law of Faunal Succession LAW OF SUPERPOSITION LAW OF ORIGINAL HORIZONTALITY LAW OF LATERAL CONTINUITY LAW OF CROSSCUTTING RELATIONSHIP LAW OF FAUNAL SUCCESSION Make a borelog at point a and b (1 cm wide) and identify which layers are producing unconfirmity LAW OF FAUNAL SUCCESSION FIND OUT THE LAWS OF STRATIGRAPHY  WHAT IS STRUCTURAL GEOLOGY?  BEDDING PLANE ELEMENTS OF  HORIZONTAL STRATA STRUCTURAL  DIPPING STRATA GEOLOGY  TYPES OF DEFORMATION  TYPES OF STRESSES  PRIMARY AND SECONDARY STRUCTURAL FEATURES OF ROCK STRUCTURAL GEOLOGY THE STUDY OF THE DEFORMATION OF THE ROCKS IN THE EARTH’S LITHOSPHERE KNOWN AS STRUCTURAL GEOLOGY. BEDDING PLANE A single stratum may be of any thickness but the layer which separates two stratums (above or below) or two layers is known as bedding plane. HORIZONTAL STRATA The areas where rocks are in horizontal state or near the horizontal position is known as horizontal strata. DIPPING STRATA A ridge which is formed of hard bed overlying a softer layer with a small to moderate dip. STRESS Force per unit area is known as stress. Lithostatic Stress: earth surface experiences equal pressure in all directions because of the weight of the overlying rock. Differential stress: Rock experience additional or unequal stress is known as differential stress. TYPES OF DIFFERENTIAL STRESSES Compressional stress; which tends to squeeze the rock Tensional stress; which tends to pull a rock apart Shear stress, which results from parallel forces that act on different parts of the rock body in opposite directions. STRAIN & DEFORMATION The deformation in rocks is said to be strain. It is a change in shape, size or volume of a material. TYPES OF DEFORMATION ELASTIC: A rock is said to deform elastically if it can return to its original size once the stress is removed. Plastic: deformation, results in permanent changes in the size and shape of the rock, even after the stress is removed.Also known as DUCTILE deformation. BRITTLE: If stress applied which is greater than its yield strength and continues to be subjected to stress may finally break, a behavior known as brittle deformation. GEOLOGICAL STRUCTURAL FEATURES OF ROCKS Primary structural feature Secondary structural feature  Fracture Joints Faults and type of faults Folds Geological mapping Break in rock body is fracture FRACTURE It is of two types dependent on movement Fault Joint JOINTS Joints are fractures in the rocks characterized by no movement along their surfaces. Although most joints are secondary structures, some are primary, forming at the time of formation of the rocks. TYPES OF JOINTS 1- Columnar joints: Are joints that form in basalts. When the basaltic lava cools, it contracts giving rise to hexagonal shaped columns. TYPES OF JOINTS 2- Mud cracks: Are joints that form in mud. As the mud loses its water, it contracts and cracks. TYPES OF JOINTS 3- Sheet joints: Are joints that form in deserts causing them to break into thin parallel sheets. These joints form when the rocks expand as a result of the rapid removal of the overlying rock cover, possibly due to faulting or quarrying. This process is called exfoliation. FOLIATION FAULTS Normal fault Reverse fault Thrust fault Strike slip fault FOLDS Related to bending Two basic kinds of folds: Syncline Anticline WHAT IS HAPPENING IN FOLD? ACTIVITY Draw the schematic diagram of different types of fold and mention their differences through figure and single line explanation. Mention at least 4 different types of phenomenon occurred in basic kind of folds through figure and explanation. Describe the process which helps in identification of anticline and syncline VERTICAL & HORIZONTAL BEDDING ANTICLINE & SYNCLINE DIP & STRIKE JOINTS & FOLIATION SYMBOLS FOR DIFFERENT STRUCTURAL FEATURES GEOLOGICAL MAPPING It provides a horizontal cross section view of the distribution and occurrence of rock bodies exposed at earth surface. It involves 3 level of information Scale Information of surface topography Information about the bed rock BASIC MAP INFORMATION Scale 1:62500 1:63360 1:100000 1:25000 Location 51º, 25', 34"N PLOTTING OF A TOPOGRAPHIC PROFILE