Wk 4 Place

Question 1

What is the role of a geotechnical engineer?

Answer 1

1. assess/define rock and soil conditions (including strength and deformation properties) of a site and
2. relay this information/data to structural engineers.

Question 2

What is the role of a structural engineer?

Answer 2

designs structural systems & members

Question 3

Outline the CHECKLIST FOR DESIGNING A STRUCTURAL SYSTEM FOR A PROJECT:

Answer 3

1. Explore Site & soil conditions (foundation)
2. Choose a structural material & a gravity load framing or walling system
3. Lay out the framing or walling system
4. Adjust the framing or walling and floor plans to fit one another
5. design and deploy a Lateral Load Resisting system
6. Shape Long Span components
7. Detail the structure
8. Check assumed member sizes using maths to determine their adequacy.

Question 4

Define FOUNDATIONS

Answer 4

earth below the building/structure that carries the load of the building/structure.

Question 5

Define FOOTING

Answer 5

the part of the building that are in
> in contact with the foundation and
> transfers the applied and dead loads of the building to the foundations

Question 6

How is the foundation classification for a particular site determined?

Answer 6

The geotechnical engineer classifies the foundation based on core samples taken from the site

Question 7

What type of foundation can we expect in a ROCKY BAY OR POINT

Answer 7

Sandstone

Question 8

What type of foundation can we expect on a ROCKY SLOPE

Answer 8

1. Bedrock OR
2. Floaters &/OR
3. Weathered rock with some clay

Question 9

What are Floaters?

Answer 9

Large rocks detached from the bedrock)

Question 10

How would we support a brick wall on a ROCKY SLOPE foundation?

Answer 10

If BEDROCK: directly off bedrock or on a concrete strip footing
if FLOATERS: if floaters are present they must be REMOVED OR STABILISED
if WEATHER ROCK/CLAY: by EXTENDING FOOTINGS DOWN TO ROCK

Question 11

How would we support a brick wall on a ROCKY BAY/POINT foundation?

Answer 11

Direction off bedrock or on concrete strip footing

Question 12

What type of foundation can we expect on EXCAVATED ROCK?

Answer 12

sandstone bedrock

Question 13

How could we support a masonry (brick) wall on an EXCAVATED ROCK foundation?

Answer 13

Directly off bedrock or on a concrete strip footing

Question 14

How could we support a concrete slab on an EXCAVATED ROCK foundation?

Answer 14

Directly off bedrock

Question 15

What type of foundation can we expect on EXCAVATED CLAY & WEATHERED ROCK ?

Answer 15

Weathered rock &/or clay

Question 16

How would we support point loads from columns on an EXCAVATED CLAY & WEATHERED ROCK foundation?

Answer 16

Extended footings down to & into the bedrock

Question 17

What type of foundation can we expect in MUDDY BAYS & RIVER EDGES?

Answer 17

Silt

Question 18

What type of foundation can we expect in SANDY BAYS & BEACHES?

Answer 18

Sand

Question 19

How would we support loads on a SILT foundation?

Answer 19

Where possible, extend footings down to bedrock

Question 20

How would we support loads on a SAND foundation?

Answer 20

Generally provides a stable foundation as long as erosion is avoided.

Question 21

What is the difficulty of building on retained slope sites?

Answer 21

Retained filled sites represent difficult foundation conditions as THE MATERIAL SUPPORTING THE BUILDING CAN BE OF VARIABLE QUALITY…Use piers down to stable foundation (preferably bedrock).

Question 22

What are the 8 types of foundations found around the harbour?

Answer 22

1. Rocky bays & points (==>sandstone foundation)
2. Rocky slopes (==> bedrock, floaters &/or weather rock & clay)
3. Excavated rock (sandstone)
4. Excavated clay & weathered rock (clay & weathered rock)
5. Muddy bays & River edges (silt)
6. Sandy bays & edges (Sand)
7. Retained bay & River edges (retaining wall holds filled area, difficulty as potential for variable quality of fill material(s))
8. Retained Slopes (retained filled material raises concern for variable quality of foundation material(s))

Question 23

What is the main cause of foundation instability?

Answer 23

Water

Question 24

What are the most stable foundation types?

Answer 24

1. Rock and

2. Sand

Question 25

What are the most UNstable foundation types and why?

Answer 25

1. Clay - due to its tendency to react with ground water. 2. Soft soils (e.g. silt) 3. Filled sites - variable quality of material supporting the buildings

Question 26

What are the general site foundation classes?

Answer 26

SAND & ROCK > A - sand & Rock CLAY/SILT - reactive, experience ground movement from moisture changes > S - slightly reactive clay > M - moderately reactive clay or silt sites > H - highly reactive clay sites >E - extremely reactive sites which can experience extreme ground movements from moisture change FILLED SITES: > A-P Filled sites >P - soft soils (clay or silt), loose sands, landslip, mine subsidence, collapsing soils, soils subject to erosion, reactive sites

Question 27

What does the appropriate method to RELAY THE LOADS OF A BUILDING TO A STABLE FOUNDATION depend on?

Answer 27

1. BEARING ABILITY of the foundation: how much load it can take 2. REACTIVITY of the foundation material (especially how it is affected by water)

Question 28

What is the 'bearing ability' of a foundation?

Answer 28

how much load the foundation can take

Question 29

What type of loads are PAD FOOTINGS used for?

Answer 29

point loads/ column / 1D

Question 30

What type of loads are STRIP FOOTINGS used for?

Answer 30

load bearing walls

Question 31

What type of loads are REINFORCED SLABS used for?

Answer 31

floors on the ground

Question 32

What are the 3 main types of footings?

Answer 32

1. PADfootings (for point loads/columns/1D) 2. STRIP footings (for line loads/ load bearing walls/ 2D) 3. SLAB footings (for Plane loads/floors on the ground/3D)