Definitions

Question 1

What is the definition of coarse-grained soil?

Answer 1

Coarse-grained soil consists of larger particles such as sand and gravel, with a size greater than 0.075m.

Question 2

What is the permeability of coarse-grained soil?

Answer 2

Coarse-grained soil has high permeability, allowing water to drain easily.

Question 3

What is sheer strength in soil mechanics?

Answer 3

Sheer strength depends on the friction between particles.

Question 4

What is compressibility in soil mechanics?

Answer 4

Compressibility refers to how quickly soil settles under load.

Question 5

What is the definition of fine-grained soil?

Answer 5

Fine-grained soil consists of smaller particles such as silt and clay, with a size less than 0.075m.

Question 6

What is the permeability of fine-grained soil?

Answer 6

Fine-grained soil has low permeability, causing water to move slowly through the soil.

Question 7

What does sheer strength depend on in fine-grained soil?

Answer 7

In fine-grained soil, sheer strength depends on cohesion and plasticity.

Question 8

How does compressibility affect fine-grained soil?

Answer 8

Fine-grained soil compresses slowly over time.

Question 9

Why are coarse-grained soils better for foundations?

Answer 9

Coarse-grained soils are better for foundations due to their strength and drainage properties.

Question 10

What are the drawbacks of fine-grained soils?

Answer 10

Fine-grained soils are more cohesive but problematic in terms of drainage and settlement.

Question 12

Gravel and sand

Answer 12

Visible and gritty

Question 13

Silt

Answer 13

Smooth feeling. Non plastic

Question 14

Clay

Answer 14

Sticky and plastic when moist due to extremely fine particles.

Question 15

Soil strength

Answer 15

Proper moisture ensures good compaction and load bearing capacity; too much or too little weakens it

Question 16

Bearing capacity

Answer 16

Moisture impacts the solid ability to support loads

Question 17

Volume changes

Answer 17

Moisture fluctuations in clayey soils cause expansion or shrinkages affecting foundations

Question 18

Permeability

Answer 18

Moisture affects soil drainage and water management

Question 19

Material durability

Answer 19

Proper moisture is needed for concrete curing.

Question 20

Frost action

Answer 20

Freezing can cause frost heaving , damages structures

Question 21

Construction delays

Answer 21

Excess moisture can slow n down work and complicate soil handling

Question 22

Attenders limits of soil

Answer 22

Used to determine the consistency and behaviour of fine grained soils at different moisture levels.they include liquid limit which is the moisture content at which soil changes from a liquid to plastic state.

Question 23

Effective stress

Answer 23

Stress carried by soil particles calculated as total stress minus pore water pressure. It determines the soils strength, stability and settlement behaviour, making it essential in geotechnical engineering

Question 24

Physical weathering

Answer 24

Breakdown of rocks into smaller pieces without changing their chemical composition

Question 25

Causes of physical weathering

Answer 25

1.Freeze thaw cycles- water enters cracks and freezes and expands and breaks the rock. 2.Thermal expansion- repeated healing and cooling causes rock to crack . 3. Abrasion- wind, water or ice carry particles that grind against rock surfaces

Question 26

Chemical weathering

Answer 26

The decomposition or dissolution of rocks due to chemical reactions

Question 27

Causes of chemical weathering

Answer 27

1. Acid rain- accelerates chemical breakdown. 2. Oxidation- reaction with oxygen, often affecting rocks with iron. 3. Carbonation - reaction with carbonic acid especially in limestone.

Question 28

Biological weathering

Answer 28

Weathering caused by living organisms

Question 29

Causes of biological weathering

Answer 29

1. Plants : roots grow into and expand cracks in rocks. 2. Animal: burrowing animals disturb and expose rock to other weathering agents

Question 30

Igneous rocks

Answer 30

1.Granite 2.Basalt

Question 31

Granite

Answer 31

- an intrusive igneous rock formed from the slow cooling of magma beneath the earths surface

Question 32

Basalt

Answer 32

And extrusive igneous rock formed from from the rapid cooling of lava at the surface

Question 33

Not igneous

Answer 33

Marble ( metamorphic) Gneiss (metamorphic) Quartzite (metamorphic) Shale ( sedimentary)

Question 34

Igneous rocks

Answer 34

Formed by the cooling of molten magma or lava. Granite and basalt

Question 35

Sedimentary rocks

Answer 35

Formed from the accumulation and compaction of sediments over time. Sandstone and shale

Question 36

Metamorphic rocks

Answer 36

When existing rocks are subjected to heat and pressure, altering their structure and composition. Marble and gneiss

Question 37

Mining + quarrying

Answer 37

these activities disturb the earths crust, accelerate erosion and disturb natural geological formations.

Question 38

Deforestation

Answer 38

removing vegetation increases soil erosion and sediment transport altering the natural sedimentary cycle.

Question 39

Burning fossil fuels

Answer 39

This replaces large amounts of co2 , which contributes to climate change and ocean acidification affecting weathering processes