Engineering Geology Ch. 1 & 2 Quiz

Engineering Geology

The study of soil, water, and rock and how these three interact with each other and with engineering materials and structures

What does engineering geology focus on?

Application of geological data, techniques, and principles to study rock, soil, and water

What is engineering geology essential for?

Proper location, planning, design, construction, operation, and maintenance of engineering structures

Foundation Engineering

Assessment of soil conditions

Construction Materials

Quality of stone, lime, cement, etc.

Infrastructure

Location of bridges and tunnels

Disaster Mitigation

Seismic resistant structure design, flood control, etc.

Water Resources Engineering

Dams and reservoir capacity, desilting, navigating channels

Environmental Engineering

Ecological balances and solid waste management

Engineering Geology

Established ~1920s with the St. Francis Dam Failure; more quantitative and physical geology; focused on construction

Environmental Geology

Established late 1960s; more qualitative and focuses on physical, chemical, and biological; broad range

William Penning

Published first book “Engineering Geology” in 1880

Rites and Watson

Published American engineering geology textbook in 1914

Conglomerate

Large grain materials put together with lots of pore spaces

Schist

Layered rock that cant bear horizontal stress

Reasons for St. Francis Dam Failure

Sedimentary rocks on the west side lost strength when wet; fault separating east and west rocks started to leak water; Schist on the east had increased pore pressure and lost its shear strength

Trans-Alaska Pipeline

Built in 1970s to transport oil from northern to southern Alaska; ground conditions and permafrost taken into consideration

Permafrost

Ground frozen for a minimum of 2 years

Leaning Tower of Pisa

Foundation of limestone and lime mortar was just 3 meters thick on soft soil from an old riverbed, which resulted in tilting starting in the 12th century

Dynamic soil-structure interaction

Seismic waves not causing soil interaction; ex. tower rides the waves and does not interact

Geology

Study of earth from different perspectives

Minerology and petrology

Composition of earth

Geomorphology

Surface expressions

Structural Geology

Structure of earth

Global Geophysics

Internal activities

Stratiography and Geochronology

Formation process

Paleontology

Ancient life

Crust

Outer layer, ~10 km thick, mostly solid

Mantle

Semi-solid, sort of molten

Inner core

Solid, pressure so intense that liquid becomes solid

Outer core

Liquid layer

Oxygen

Most abundant element in earth’s crust and mantl

Rock (Geological)

Solid material forming the outer rocky shell/crust of the earth

Igneous

Source of all rocks, rocks cooled from molten stateI

Igneous Rocks

Obsidian, granite, basalt

Sedimentary

Deposited from a fluid medium, products from weathering or erosion of rocks

Sedimentary Rocks

Sandstone, mudstone, shale, limestone

Metamorphic

Formed from pre-existing rocks by the action of heat and pressure

Metamorphic Rocks

Schist, marble, dolomite

Intrusive Igneous Rocks

Magma that solidifies before emerging from earth’s crust; cools slowly; individual grains are larger; coarse

Extrusive Igneous Rocks

Rocks that form on surface; cools faster; more porous (small grains)

How do sedimentary rocks form?

All sediments mix then settle down and solidifyA

Aeollan

Wind blown sediments

Sedimentary rocks formation types

Alluvial, fluvial, evaporite, tidal, deltaic, lagoonal, and lacustrine

Types of metamorphic rocks

Regional and contact

Metamorphic Grade

Shale → Slate → Schist → Gneiss →Migmatite

What is the metamorphic grade?

Order of rocks from grade with increase pressure and temperature

How are Igneous rocks formed?

Internal heat

What forms Sedimentary rocks?

Igneous and metamorphic rocks with weathering and erosion then lithifying

What forms metamorphic rocks?

Igneous, sedimentary and metamorphic rocks though heat and pressure

Divergent Plate

Plates separate and magma comes to the surface forming new plates; spreading, constructive, ridges/rift

Convergent Plate

Plates move towards each other building up stress; subduction, destructive, trench

Transverse (Strike-Slip) Plate

Plates slide by each other in opposite directions; lateral sliding, conservative, no topography effect

Subduction

Where two plates colloid and the denser plate, like ocean plates, go below the other plate

Plate tectonic settings of volcanoes

Mid-Oceanic ridges

Intrusive Mid-Oceanic Ridges

Diorite, gabbro, granite

Extrusive Mid-Oceanic Ridges

Andesite, Basalt

Continental Hot Spot

The crust moves over unmoving magma, forming islands and burnt ridges; ex. Hawaii

Criterial for Mineral Classification

Naturally occurring chemical element or compound, formed by inorganic processes, ordered arrangement like crystalline structure, and definite chemical composition

Mineral

A naturally occurring inorganic crystalline solid with set chemical composition and characteristic physical properties

Mineral physical properties

Shape, hardness, density, luster, color, streak, reaction to acid, and magnetism

Types of shapes in minerals

Growth shape, cleavage, and fracture

Types of growth shapes in minerals

Cubic, tetragonal, triclinic, orthorhombic, hexagonal, monoclinic, and trigonal

Mohs Hardness Scale

Scale from 1-10, with 10 being the hardest

Types of scratch tests for Mohs hardness scale

Fingernail (2.5), Penny (3.5), Knife/glass plate (5.5), Steel nail (6.5), masonry drill bit (8.5)

Silicate Minerals

90% of Igneous rocks and 40% of common minerals

Types of silicate minerals

Brick, stone, concrete, glass, feldspar, quartz, ferromagnesium (Fe or Mg), nonferromagnesium (Ca, K, Na)

Sulfide Mineral

Pyrite

Oxide Mineral

Hematite

Sulfate mineral

Gypsum

Calcite (CaCO3)

Fizzes with acid, used in cement manufacturing, cave formation - major constituent

Aragonite (CaCO3)

Polymorph of calcite; same formula, different crystal structure

Dolomite (CaMg(CO3)2)

Very prevalent in the past and scare now

Limestone

Calcite and aragonite rock called limestone, which is what sinkholes come from

Dolostone

Dolomite containing rock

Clay Minerals

Very fine-grained minerals found in soil

Non-swelling clay types

Kaolinite, halloysite, illite

Swelling clay types

Vermiculite, smectite

Smectite

Grow 200% in size, used in drilling mud since it swells when exposed to water

Kaolinite

Made up of high grade clay, used in manufacture of ceramic products, rubber industry, and refactories

Illite

Chief constituent in shales