LE 2 CONCEPTS (M7 - M12)

Question 1

The pressure transmitted through grain to grain at the contact points through a soil mass

Answer 1

Effective Stress

Question 2

If the pores of a soil mass are filled with water and if a pressure induced into the pore water, tries to separate the grains, this pressure is termed as ______________

Answer 2

Pore Water Pressure (u)

Question 3

TRUE OR FALSE

The higher the friction between the particles, the lower the effective stress

Answer 3

False

Question 4

TRUE OR FALSE

The lower the effective stress, the lower the strength of the soil

Answer 4

True

Question 5

TRUE OR FALSE

Increasing the pore water pressure decreases the effective stress, thereby
decreasing the strength

Answer 5

True

Question 6

Assumption where surface load is assumed to be applied on soil that is bounded on one side and extends infinitely in all other directions

Answer 6

Semi-infinite

Question 7

Assumption where surface load is assumed to be applied on soil that has the same soil properties with depth

Answer 7

Homogeneous

Question 8

Assumption where surface load is assumed to be applied on soil that has the same soil properties in all directions

Answer 8

Isotropic

Question 9

Assumption where surface load is assumed to be applied on soil that has recoverable strain where principle of superpostition is applicable

Answer 9

Linear elastic

Question 10

General classes of surface load that is either point load, circular load, rectangular load

Answer 10

Finite Surface Load

Question 11

General classes of surface load that is either fills, surcharges

Answer 11

Infinite Surface Load

Question 12

A stress increase caused by the construction of foundations or other loads compresses soil layers

Answer 12

Compressibility

Question 13

caused by the elastic deformation of dry soil and of moist and saturated soils without any change in the moisture content

Answer 13

Elastic settlement or Immediate settlement

Question 14

result of a volume change in saturated cohesive soils because of expulsion of the water that occupies the void spaces

Answer 14

Primary consolidation settlement

Question 15

observed in saturated cohesive soils and is the result of the plastic adjustment of soil fabrics

Answer 15

Secondary consolidation settlement

Question 16

occurs directly after the application of a load without a change in the moisture content of the soil

Answer 16

Elastic Settlement

Question 17

When a saturated soil layer is subjected to a stress increase, the pore water pressure is increased suddenly

Answer 17

Primary consolidation settlement

Question 18

A simple ground improvement technique, where the soil is densified through external compactive effort

Answer 18

Compaction

Question 19

TRUE OR FALSE

Compaction increases the strength characteristics of soils, which increases the bearing capacity of foundations constructed over them

Answer 19

True

Question 20

TRUE OR FALSE

Compactions increase the amount of undesirable settlement of structures

Answer 20

False

Question 21

TRUE OR FALSE

Compaction increases the stability of slopes of embankments

Answer 21

True

Question 22

TRUE OR FALSE

Compaction causes more water seepage, swelling and contraction

Answer 22

False

Question 23

the maximum unit weight that a soil can attain using a specified means of compaction

Answer 23

Maximum dry unit weight

Question 24

the water content required to allow a soil to attain its maximum dry unit weight following a specified means of compaction

Answer 24

Optimum moisture content, OMC

Question 25

The four most common types of rollers

Answer 25

1. Smooth-wheel rollers (or smooth-drum rollers) 2. Pneumatic rubber-tired rollers 3. Sheepsfoot rollers 4. Vibratory rollers

Question 26

for proof rolling subgrades and for finishing operation of fills with sandy and clayey soils

Answer 26

Smooth Wheel Roller

Question 27

- Better than the smooth-wheel rollers. - It is heavily loaded with several rows of tires. - for sandy and clayey soil compaction. - Compaction is achieved by a combination of pressure and kneading action.

Answer 27

Pneumatic Rubber-Tired Rollers

Question 28

- drums with a large number of projections. - Most effective in compacting clayey soils

Answer 28

Sheepsfoot Roller

Question 29

extremely efficient in compacting granular soils. - Vibrators can be attached to smooth-wheel, pneumatic rubber-tired, or sheepsfoot rollers to provide vibratory effects to the soil. The vibration is produced by rotating off-center weights.

Answer 29

Vibratory Rollers

Question 30

the resistance to movement between particles due to physical bonds from: -Particle interlocking -Atoms sharing electrons at surface contact points -Chemical bonds (cementation) such as crystallized calcium carbonate

Answer 30

Shear strength in soils

Question 31

the oldest and simplest form of shear test arrangement

Answer 31

Direct Shear Test

Question 32

Common Laboratory tests for Shear Strength

Answer 32

* Direct shear test * Triaxial shear test * Unconfined compression test