Written Test3

Question 1

What is failure ?

Answer 1

A state when the element can no longer be used as intended,

cannot be rehabilitated

Question 2

What is Strain ?

Answer 2

– The relative elongation/compression of an element

Question 3

What is Shear Strain ?

Answer 3

The change in angle between two line elements originally at right
angles

Question 4

What is viscoelastic materials ?

Answer 4

Time dependence Materials , The behaviour often changes as time progresses . ( CREEP )

Question 5

What is Deformation

Answer 5

The physical combination of strains and shear strains or the change in volume and shape

Question 6

Principal Strains ?

Answer 6

– For every point in a body there is a coordinate system
directed such that the strain state can be
characterized by the normal strains only
– These normal strains are then denoted principal
strains

Question 7

What is invariants ?

Answer 7

Ki is independent of the 
chosen coordinate system 
They are used to transform 
strains between coordinate 
systems

Question 8

What are compatibility Equations ?

Answer 8

Strain relations used to ensure that the deformations

is compatible with displacements and are continuous

Question 9

Constitutive Equations ?

Answer 9

Mathematical relations between stresses and strains

- the material models

Question 10

Geomechanical Sign conversion

Answer 10

Displacements are positive when acting in the coordinate axes
positive directions
– Normal strains are considered positive at compression

Question 11

Settlement ?

Answer 11

Surface Deformations

Question 12

• Elastic and plastic deformations ?

Answer 12

– Reversible and permanent

Question 13

What is Elasticity ?

Answer 13

Describes the behavior of material in which after
discontinuing the applied stress the entire
deformation remains reversible; the relationship
between stress and strain is usually linear.

Question 14

What is Plasticity ?

Answer 14

Describes a behavior of material which can deform
continuously without failure under stresses
surpassing the one necessary to cause yielding.
• Relate to the concept of residual strength

Question 15

What is Young Modulus

Answer 15

E is the stiffness or ”deformation resistance”

of the material

Question 16

What is Poisson’s ratio

Answer 16

ν is the relationship between the
axial and tangential strain for a
given axial stress

Question 17

K ?

Answer 17

Bulk Modulus

Question 18

G ?

Answer 18

Shear Modulus

Question 19

Laboratory Tests ?

Answer 19

– Uniaxial compression test

– Sound velocity test

Question 20

Field Tests ?

Answer 20

– Plate loading test
– Dilatometer measurement
– Seismic measurement

Question 21

How will you determine young modulus in Uniaxial Compressive Test

Answer 21

Tangential Young’s modulus, (Et) is
calculated when the stress level is equal to
about 50% of the uniaxial compressive
strength.
Average modulus (Eav) is calculated from the slope on the linear part of the stress‐strain curve

Question 22

what are the 2 basic assumptions of the Dilatometer Test

Answer 22

• Tested volume must be free of joints to avoid
  hydraulic fracturing and joint opening
  • Is independent on the prevailing stresses!

Question 23

impoving the slope stability ways ?

Answer 23

Changing Geometry
change water conditions
Installing Reinforcments
Dmage preventions ( smooth plasting and pre split )
Controlling rock falls ( catch benches , fences , nets )

Question 24

Slope monitoring methods ?

Answer 24

*Geodetical Methods ( prisms and base station ) + base movement.
• Extensometer or Inclinometer
(failure surface)
• Vertical boreholes (groundwater)

Question 25

stability is determined in footings on rock surfaces ?

Answer 25

– bearing capacity
– unacceptable settlements
– Slope stability

Question 26

How to measure deformation in site ?

Answer 26

Extensometer measurments
Convergence Measurment
Geodetic Measurments