1.6 Excavations

Question 1

In connection with excavations, what is ‘battering’?

Answer 1

Battering back the sides of an excavation to a safe angle to prevent instability

Question 2

What is being described below:

The angle measured in degrees to the horizontal
which ground material, if left, will ultimately form to
become completely stable.

Answer 2

angle of repose

Question 3

What is being described below:

load applied to the ground by plant, stored
materials, spoil or structures increases
the horizontal load on the excavation sides

Answer 3

surcharging

Question 4

How far away from an excavation should materials etc. be stored?

Answer 4

Min 1.5m or > depth of excavation

Question 5

There are three main control measures to avoid underground services. What are they?

Answer 5

 Checking of existing plans
 Use of CAT tools
 Appropriate digging techniques

Question 6

When should excavations and any work equipment or materials that may affect its safety be inspected by a competent person (i.e. someone with sufficient training and experience of excavation work):

Answer 6

 the start of every shift
 after any event likely to have affected its strength or stability
 after any material unintentionally falls or is dislodged

Question 7

What is being listed listed below:

 Ground movement / collapse of excavation sides
 Surcharging
 Ground and surface water
 Stability of adjacent structures and services
 Underground services
 Overhead lines
 People falling into excavations
 Plant falling into excavations
 Materials falling into excavation
 Toxic gas and oxygen deficiency
 Biological and chemical health hazards
 Noise and vibration.

Answer 7

The main hazards associated with excavations