Topic 5.1.2

Question 1

What are the permanent support systems

Answer 1

Diaphragm walls
Contiguous bored pile walls
Secant pile walls
Soldier pile walls

Question 2

D-Wall construction sequence

Answer 2

1. Construction of guide wall
2. Excavation of panel
3. Installation of rebar cage
4. Concreting of panel
5. Repetition of process

Question 3

How do D-Walls achieve stability

Answer 3

Struts in the form of floor structure
Ties in the form of ground anchors

Question 4

Where can CBP walls be used

Answer 4

Suitable for crowded urban areas
Can only be used where ground water is not a hazard

Question 5

What sizes do CBP piles come in

Answer 5

600mm-1500mm in diameter
25m in depth

Question 6

What do secant piles consist of

Answer 6

Soft piles that are bored using contiguous flight auger drill rigs and concreted first
Hard piles that are drilled and cut into the soft piles

Question 7

What sizes do secant piles come in

Answer 7

500mm-1200mm

Question 8

Where can secant piles be used

Answer 8

Deep basement walls
To cut off walls for control of groundwater inflow

Question 9

Construction of soldier pile wall

Answer 9

Install piles
Excavate and place lagging
Install support

Question 10

Types of lagging

Answer 10

Timber
Precast concrete
Steel sheeting
Wire mesh with shotcrete

Question 11

Advantages of soldier piles

Answer 11

Lower cost compared to other retaining wall systems
Fast construction
Builders have control over spacing and layout of all materials
Minimal vibrations and noise