Intro To Geotech - Exam 1

Front 1

igneous rocks

Back 1

formed by magma cooling asit moves upward toward the ground surface

Front 2

describe intrusive igneous rocks

Back 2

1) below the ground surface;

2) slow coolingprocess;

3) coarse grained

Front 3

decribe extrusive igneous rocks

Back 3

1) at the ground surface;

2) rapidcooling;

3) fine grained

Front 4

name 3 intrusive igneous rocks

Back 4

1) granite

2) diorite

3) gabbro

Front 5

name 3 extrusive igneous rocks

Back 5

1) rhyolite

2) andesite

3) basalt

Front 6

sedimentary rocks

Back 6

formed by soildeposits that have transformed into rock through hardening process calledinduration or lithification

Front 7

describe clastic sedimentary rocks

Back 7

formed by pressure from overlying strata andcementation through precipitation; layered/stratified

Front 8

describe carbonate sedimentary rocks

Back 8

organic materials origin; generallyconsisting of CaCO3 (calcium carbonate)

Front 9

name 3 clastic rocks

Back 9

1) Sandstone

2) Shale

3) Conglomerate

Front 10

name 3 carbonate rocks

Back 10

1) limestone

2) chalk

3) dolomite

Front 11

describe a sinkhole

Back 11

carbonate rocks are dissolved by long exposure to acidic water and cause underground caverns; the soil above caves into the caverns

Front 12

metamorphic rocks

Back 12

formed by both igneous and sedimentary rocks subjected to intense heat and pressure

Front 13

name 3 types of foliated metamorphic rocks

Back 13

1) slate

2) schist

3) gneiss

Front 14

name 2 types of nonfoliated metamorphic rocks

Back 14

1) quartzite

2) marble

Front 15

physical weathering

Back 15

disintegration of rocks into smallerparticles through physical or mechanical process

Front 16

chemical Weathering

Back 16

disintegrationof rocks through chemical reactions between the minerals in the rock, water,and oxygen

Front 17

residual soils

Back 17

soils that remain in place becauseof faster weathering process than the transporting process; common in tropicalregions

Front 18

Transported Soils

Back 18

soils that formed by the deposition ofsediments that have been transported from their places of origin by various agents

Front 19

GlacialSoils

Back 19

transportedby glaciers

Front 20

Alluvial(or Fluvial) Soils

Back 20

transportedby rivers and streams:92768

Front 21

Lacustrineand Marine Soils

Back 21

transportedbeneath lakes and ocean,respectively

Front 22

AeolianSoils

Back 22

transportedby wind

Front 23

Colluvial Soils

Back 23

transported downslope by gravity suchas landslide

Front 24

describe till glacial soils

Back 24

unsortedand unstratifiedglacial sediments directlydeposited by glaciers

Front 25

describe outwash glacial soils (glaciofluvial soils):

Back 25

soils deposited by meltwaterstreams flowing beyond the margin of the glacier carry

Front 26

characteristics of using a test pit

Back 26

- Continuousprofile

- Shallowerdepths

- Disturbedsample

Front 27

characteristics of using drilling

Back 27

- Morecommon technique

- Deeperdepths

- Lessdisturbed sample

Front 28

site exploration steps

Back 28

1) Reviewof background information

2) Fieldreconnaissance

3) Field exploration (drilling, sampling, in-situ testing)

4) Laboratory testing (Chapters 10 and 12)

5) Geotechnicalinterpretations/Analysis

6) Reporting

Front 29

solid stem auger

Back 29

Suitable for firm and dense soils but may not be drilled further if hardbouldersare encountered

Front 30

hollow stem auger

Back 30

hollow stem casing provideslateral support insidethe hole during drilling and hence reduces the possibility of caving; suitable for looser soils

Front 31

mud rotary drilling

Back 31

Drillingfluid provides a hydrostatic pressure to preventcaving (suitable for loose sand below GWT)

Front 32

rock coring

Back 32

Hole is advanced with a rotary diamonddrill bit (hollow cylinder), and nearly continuous undisturbed samples, rockcores,are obtained.

Front 33

Shelbytube sampler

Back 33

- A thin wall tube islowered to the bottom of the boring, then smoothly pressed intothe soil.

- Used for clayey soils toobtain “undisturbed” sample

- Thelarger the tube diameter, the less the sample disturbance

Front 34

split spoon sampler

Back 34

- A split spoon tube islowered to the bottom of the boring, then drivenintothe soil with a hammer

- Typically used for sandy soils toobtain sample (samples obtained from split spoon sampler are moredisturbedthan those from Shelby tube)

Front 35

StandardPenetration Test (SPT)

Back 35

- Drivethe split spoon sampler over 18 in (45cm)

- Recordno. of blows per each 6 in (15 cm) penetration

- Stopthe test if more than 50 blows are required for anyof the intervals (refusal).

- Stopthe test if more than 100 totalblows are required (refusal)

Front 36

ConePenetration Test (CPT)

Back 36

A hydraulic ram pushesthe cone assemblyinto the ground and instruments measure resistance topenetration.

Front 37

CPT vs. SPT

Back 37

CPT Advantages:

- Providesmuch more reliable datawith better resolution.

- Providescontinuous profile

CPT Disadvantages:

- Doesnot give a sample

- Needto mobilize a special rig to perform CPT

- Cannotbe performed to deeper depths in very dense soils or gravelly soils

Front 38

soil is...

Back 38

- a natural material

- a particulate material

- consists of all three phases of matter