Intro to piling 3-9 October

Question 1

Main use of strip foundations

Answer 1

Transferring long continuous loads such as walls when ground conditions are good

Question 2

What is the purpose of a foundation?

Answer 2

To transfer load from a structure to the ground safely without causing unacceptable settlement

Question 3

Name three factors that affect foundation choice

Answer 3

Type, weight/ use of structure, ground/soil conditions

Question 4

Name the main use of a pad foundation

Answer 4

Underneath point loads such as columns

Question 5

What is the purpose of rienforced concrete raft foundations?

Answer 5

Spread the load over a whole building area reducing the load per unit area

Question 6

When are raft foundations used?

Answer 6

when building loads are high and/or ground conditions are poor

Question 7

How do piles work?

Answer 7

takes the load through weak soil to load bearing strata

Question 8

What does CFA stand for?

Answer 8

Continuous flight auger

Question 9

What is step one of CFA construction?

Answer 9

Auger is lowered to the ground to start drilling and is not removed during drilling as it supports the bore sides

Question 10

What is step two of CFA construction?

Answer 10

Drill to the design depth

Question 11

What is step three of CFA construction?

Answer 11

Concrete is delivered through the center of the auger to the base of the bore and auger is removed at the same rate as concrete fill, excavated soil is to be disposed of

Question 12

What is step 4 of CFA construction?

Answer 12

Reinforcement cage is added to the wet conrete

Question 13

What is an auger?

Answer 13

A tool resembling a large corkscrew used for boring

Question 14

What are the advantages of CFA?

Answer 14

Quiet
vibration-free
no casing
can be used when rocks are weak

Question 15

State the disadvantages of CFA

Answer 15

Blind piling
Tolerances
Depth limitation
Obstructions
bore spoil

Question 16

What classification are CFA piles?

Answer 16

Replacement usupported

Question 17

What classification are CFA piles?

Answer 17

Install casing and begin drilling through strata layers
When drills reach firm strata at design depth reinforcement cage is lowered into the hole and concrete is poured

Question 18

What are the steps for rotary bored piling?

Answer 18

Install casing and begin drilling through strata layers
When drill reaches firm strata at correct depth lower reinforcement cage into the hole and pour concrete

Question 19

Advantages of rotary bored piling

Answer 19

Range of diameters
High load capacity
Ground is seen
Can be used on adverse ground
Rock boring in all rocks
Obstructions are dealt with

Question 20

Disadvantages of rotary bored piling

Answer 20

Slow
Soil to be disposed of
Expensive
Lots of bore supports needed

Question 21

What classification is rotary bored piling

Answer 21

Replacement supported

Question 22

What are the advantages of driven cast in-situ piling?

Answer 22

Rapid installation
Economical
Enhanced based resistance
Deals with obstructions
No spoils

Question 23

Disadvantages of driven cast in-situ piling?

Answer 23

Noisy
Vibrates a lot
Limited length

Question 24

What’s is the classification of driven cast in-situ piling?

Answer 24

Displacement driven cast in-situ

Question 25

What are the advantages of driven precast concrete piles?

Answer 25

Versatile
Economical
Clean site
No spoils

Question 26

What are the disadvantages of driven precast concrete piles?

Answer 26

Noisy
Lots of vibrations
Waste
Can’t deal with obstructions

Question 27

What is the classification of driven precast concrete piles?

Answer 27

Displacement preformed concrete